Why government ductwork is its own discipline
A federal departmental office tenancy at first glance looks like a commercial office — same NCC Class 5 base classification, same AS 1668.2 ventilation rates, same AS 2107 acoustic target for general open plan. A mechanical engineer who has specified a typical Sydney CBD tower or a Collins Street Melbourne tenancy could reasonably assume the brief is portable. It is not.
The federal estate sits on top of the commercial envelope an additional set of overlays that change the duct design in ways the commercial standard does not anticipate. The first is the Protective Security Policy Framework, the federal-level security regime administered by the Attorney-General's Department, which classifies every working space into a security zone and dictates the construction class of every envelope. The second is the ASIO T4 Protective Security policy framework, which provides the technical detail for hardened zones, TEMPEST shielding, secure briefing rooms and Restricted Zone Class A holdings. The third is the Information Security Manual issued by the Australian Cyber Security Centre, which governs the cyber and emissions security of classified IT spaces. The fourth, for Defence, is the Defence Industry Security Program, which clears the contractor and the installer crew before they touch the envelope. Layered on top of these is the federal heritage protection regime applied to Old Parliament House, Australian Parliament House on Capital Hill and a number of departmental buildings of architectural significance, plus the state heritage regimes at Macquarie Street Sydney, Spring Street Melbourne, George Street Brisbane and equivalents.
What this means for ductwork is concrete and specific. Inside a single federal departmental tenancy the engineer is now sizing five distinct duct streams. A general office stream in galvanised mild steel for the open plan, meeting rooms and corridors. A heritage-concealed stream routed through structural voids for any space inside the heritage envelope. A stainless steel TEMPEST shielded stream for the cabinet room, the SCIF, the secure briefing room and the classified server room. A spark-resistant stream for the UPS battery room and the generator exhaust under AS/NZS 60079. And a public-facing stream for the passport counter, the Centrelink front office or the equivalent state-level service counter, with its own filtration, pressure regime and security overlay. All five duct streams need to be produced on a single line, delivered on a single schedule, and installed by a single cleared contractor with documented chain of custody.
This guide reads through every one of those zones, calls out the binding code references and the binding security overlays, and finishes with the machinery configuration SBKJ recommends to produce the entire batch from the SBKJ production cell. It is written for the mechanical services consultant, the principal contractor, the federal Department of Finance Australian Government Property Group, the state government property authority and the cleared installer crew. It is not a substitute for the Protective Security Policy Framework documentation, the Information Security Manual or the ASIO T4 technical guidance — those documents govern, and the cleared design team works to them. This guide sits underneath that hierarchy and answers the operational question that arises after the security brief is set — how is the duct actually built.
Zone 1 — the general departmental office floor
Most federal employees work on a general departmental office floor. A Treasury floor in the Langton Crescent precinct at Parkes. A Department of Finance floor in the adjacent block. A Department of Foreign Affairs and Trade floor in the RG Casey Building at Barton. A Department of Home Affairs floor in the central Canberra precinct. A regional ATO office in Brisbane, Sydney, Melbourne, Perth, Adelaide, Hobart or Darwin. A Services Australia back-of-house floor in any of fifty large suburban office leases across the country. A Department of Veterans' Affairs floor at Brindabella Park. A Department of Climate Change, Energy, the Environment and Water (DCCEEW) floor in Canberra. A Department of Social Services floor. A Department of Health and Aged Care floor. A Department of Education floor. A Department of Employment and Workplace Relations floor. A Department of Industry, Science and Resources floor. A Department of Infrastructure, Transport, Regional Development, Communications and the Arts floor. An Australian Public Service Commission floor.
These floors are NCC Class 5 commercial office, built against AS 1668.2 with a ventilation rate of 10 L/s per person, AS 4254 ductwork construction in TDF20 or equivalent, AS 2107 acoustic at NC 35 to NC 40 for general open plan and corridor, and the NCC fire and smoke management overlay. The mechanical envelope is essentially the same as a commercial CBD tower — an outline of which is in the SBKJ commercial office tower HVAC duct guide. The setpoint is 22-23 °C at 50% relative humidity. Six to eight air changes per hour is typical. The supply ductwork is galvanised mild steel in Z275 coating, the return is either ducted or run through a sealed plenum riser, and the perimeter zones carry their own VAV terminals.
What differs is the security overlay. Even on a general open plan, the PSPF Security Zone 2 or Zone 3 classification applies. Document handling, visitor control, internal partitioning and end-of-tenancy decommissioning all carry obligations beyond the commercial standard. For the ductwork specifically, this means three things. The duct penetrations through the tenancy boundary must be documented and signed off. The return air path must not commingle with adjacent tenancies in a shared base-building riser. And the access panels for filter change and damper service must be located inside the secured tenancy boundary, not on a public corridor. SBKJ produces the galvanised general office duct on the SBAL-V auto duct line as a standard configuration — it is the workhorse output of the line.
Zone 2 — the executive office and the senior officials private office
Every federal department has a Secretary — the senior civil servant equivalent of a chief executive. Below the Secretary are Deputy Secretaries, then First Assistant Secretaries, then a layer of Senior Executive Service officers. The departmental Secretary occupies an executive office, typically with an attached anteroom for staff and a private meeting space adjacent. Deputy Secretaries and Senior Executive Service officers occupy private offices — not as elaborate as the Secretary's but still walled, with door, with private climate control and with a higher acoustic standard than the open plan.
The mechanical brief for these spaces is a clean private climate at 22 °C with a tight tolerance of plus or minus 1 K, 50% relative humidity, AS 2107 acoustic at NC 30, and a dedicated VAV terminal per office. The ventilation rate stays at 10 L/s per person but the diffuser face velocity drops to keep the room quiet enough for a recorded phone call or a video conference with a counterpart in another capital. The supply ductwork is the same galvanised mild steel as the open plan, sized down to the smaller branch dimensions and with acoustic lining on the last three metres of the branch run. The return is ducted, not via plenum, to keep audio paths clean.
The security overlay at this layer adds two requirements. The office is typically inside the working zone boundary, with no shared returns to the corridor. And the secure cabinet or safe inside the office may be on a separate environmental control if it holds particularly sensitive material — though this is normally handled by the safe manufacturer rather than the building HVAC. SBKJ produces this duct on the SBAL-V line as part of the same batch as the general office duct, with a coil change unnecessary because the material is the same.
Zone 3 — the meeting room and the secure briefing room
Meeting rooms in the federal estate fall on a spectrum. At one end is the general meeting room — book it with the online room booking system, walk in with a laptop, hold a thirty-minute stand-up. At the other end is the secure briefing room — cleared attendees only, no devices allowed, hardened envelope, a single dedicated comms link to ministerial offices. The HVAC brief follows the spectrum.
The general meeting room is built against AS 1668.2 at 10 L/s per person, AS 2107 at NC 30 to NC 35 depending on the recording specification, and a dedicated VAV terminal. Ductwork is galvanised mild steel. The supply and return paths are dedicated to the meeting room, not shared with the corridor, to give the occupants acoustic and thermal stability during a 60 to 90 minute session.
The secure briefing room is built against AS 1668.2 at 10 L/s per person but with all extract isolated from the general AHU, AS 2107 at NC 25 to support clean audio recording, TEMPEST shielded penetrations, stainless steel sealed-seam plenum for the supply, vibration-isolated supports, anti-tamper grilles on every opening and isolated extract back to a controlled relief shaft. The pressure cascade runs slightly positive against the corridor to keep outside air from entering when the door opens. The construction class follows the ASIO T4 technical guidance and the Information Security Manual sections on TEMPEST. SBKJ produces the stainless steel plenum for these rooms on the SBAL-V line with a coil change to 304 stainless, with welded joints by the SB-ZF1500 stitchwelder, and with all support brackets sized to the heavier wall thickness and the vibration isolator specification.
Zone 4 — the cabinet room
The Cabinet Room at Australian Parliament House on Capital Hill is the meeting room of the federal executive — the Prime Minister and the Cabinet Ministers of the Commonwealth. The state equivalents sit at Macquarie Street Sydney, Spring Street Melbourne, George Street Brisbane and the equivalent precincts in Perth, Adelaide and Hobart. The cabinet rooms are Restricted Zones — the most sensitive working spaces in the federal and state executives.
From publicly available information, the cabinet room HVAC brief carries the following characteristics. The room sits on a dedicated AHU branch with no shared returns to any adjacent space. Every duct penetration through the cabinet envelope is sleeved, shielded and bonded so the room functions as a Faraday cage continuous with the building earth. The acoustic target is NC 25, well below the AS 2107 general office baseline, requiring lined branches and very low face velocities at every supply diffuser. The extract air is filtered and isolated, not returned to the general AHU. The room runs slightly positive to its anteroom to keep outside air from entering during occupancy — the deliberations should not be capable of leaking out through air paths, and the anteroom should not be capable of leaking in. The kitchen and pantry serving the cabinet room are on a separate exhaust with no common run — food preparation smells and noise belong outside the deliberative envelope. The entire mechanical scope is delivered by a cleared installer crew with documented chain of custody on every fitting from coil change at the production cell to commissioning at the building. The default materials are stainless steel for the secure plenum and galvanised for everything outboard of the envelope.
The cabinet anteroom — the secure transition space between the corridor and the cabinet room itself — runs at slightly negative pressure relative to the cabinet room and slightly positive relative to the corridor. Its ventilation rate stays at 10 L/s per person but its acoustic target sits at NC 30, between the cabinet room and the general office. The cabinet kitchen runs on its own exhaust, with no commingling with the general office return, and is sized for the meal service load including stove, oven and dishwasher.
Heritage constraints apply at Parliament House and the state parliaments. The cabinet rooms sit inside heritage-protected envelopes that limit visible ductwork and restrict surface penetrations. The mechanical solution routes the cabinet branch through structural voids, with concealed slot diffusers, return paths run behind plasterboard and the access panels located on the non-heritage face of the partition. SBKJ produces the cabinet room plenum on the SBAL-V line in 304 stainless with the SB-ZF1500 stitchwelder for the welded joints. The dispatch documentation includes the chain of custody log required by the cleared contractor.
Zone 5 — the Sensitive Compartmented Information Facility (SCIF) and the Compartmented Information Facility (CIF)
The Sensitive Compartmented Information Facility, and its closely related counterpart the Compartmented Information Facility, is an accredited workspace where compartmented intelligence material is handled. The Australian implementation aligns with the ASIO T4 Protective Security policy framework and the relevant sections of the Information Security Manual. Examples of agencies that operate SCIF or CIF space include the Australian Security Intelligence Organisation, the Australian Secret Intelligence Service, the Australian Signals Directorate, the Office of National Intelligence, intelligence components within the Department of Defence, the Department of Home Affairs, the Australian Federal Police and a number of departmental policy teams that handle classified material.
SCIF and CIF ductwork has three signature features. The envelope is shielded — every penetration is TEMPEST treated, the ducts are isolated from the building's general mechanical services, and the room sits on its own AHU branch. The penetrations are small — typically below the size that admits a person or a long acoustic path — and protected with anti-tamper grilles and welded bar arrays where appropriate. The plenum is built from stainless steel, sealed-seam, with vibration isolators at every transition so structural-borne audio cannot couple into the duct.
The pressure cascade runs positive within the SCIF against the corridor at plus 12.5 Pa minimum. This keeps outside air from entering when the door opens and keeps the SCIF integrity intact during a fire alarm overpressure event. The HVAC system supports a continuous occupancy of cleared personnel during operational hours and switches to a holding mode outside operational hours, with the security envelope held by the access control system rather than active HVAC.
SBKJ delivers SCIF plenum on the same SBAL-V auto duct line as the galvanised general office product, with a coil change to 304 stainless and the SB-ZF1500 stitchwelder for the welded joints. The dispatch documentation includes a complete material certificate, a heat number trace, a weld procedure record and the chain of custody log. The cleared installer crew receives the batch under documented handover.
Zone 6 — the council chamber, the parliamentary chamber and the committee room
The state parliaments operate their primary debating chambers as the centre of the building. The Legislative Assembly and Legislative Council at Macquarie Street Sydney. The Legislative Assembly and Legislative Council at Spring Street Melbourne. The Legislative Assembly at George Street Brisbane — Queensland is unicameral, having abolished its upper house in 1922. The Legislative Assembly and Legislative Council in Perth. The House of Assembly and Legislative Council in Adelaide. The House of Assembly and Legislative Council in Hobart. The ACT Legislative Assembly in Canberra and the NT Legislative Assembly in Darwin — both unicameral. And at the federal level, the House of Representatives Chamber and the Senate Chamber at Australian Parliament House on Capital Hill.
These chambers carry a distinct HVAC brief. Ventilation is sized at 15 to 20 L/s per person to support the high occupancy of a full sitting with members, advisers, Hansard staff, attendants and broadcast crew. The acoustic target is NC 25 or NC 30 to support broadcast quality audio — Hansard and the parliamentary broadcast are recorded live, with the audio feed distributed to media. The lighting load is high to support broadcast television cameras, so the cooling load is correspondingly high. The supply paths use ducted distribution with slot diffusers concealed in the architectural ceiling, and the return is via dedicated risers, not via shared plenums, to keep audio paths clean.
Reverberation time control under AS 2107 requires careful coordination between the architect, the acoustic consultant and the mechanical engineer. The duct geometry contributes to the room acoustic via supply diffuser location, return register velocity and the acoustic absorption of the lined branch run. SBKJ supplies the chamber duct in galvanised mild steel from the SBAL-V line, with optional acoustic lining inserted on the branch run in the manufacturing cell, and with welded transitions on the larger trunks fabricated by the SBLR-600 welder. For the heritage chambers at Macquarie Street, Spring Street and equivalents, the duct routing is concealed behind the heritage joinery.
Committee rooms operate at lower occupancy than the chamber but carry the same acoustic standard. The Senate Estimates Committee room at Australian Parliament House, the Joint Standing Committee rooms, the state parliament committee rooms — all are recorded and broadcast, and all carry NC 25 to NC 30 acoustic targets. The ventilation rate is 10 L/s per person and the supply ductwork is galvanised mild steel with acoustic lining on the branch.
Zone 7 — the press gallery and the media briefing room
The press gallery at Australian Parliament House occupies dedicated office space within the building, housing the working journalists of the federal political bureau. The state parliament press galleries occupy equivalent space at Macquarie Street, Spring Street, George Street and the other state capitals. The media briefing rooms — the Blue Room at Parliament House Canberra, the various state equivalents — host televised press conferences and ministerial doorstops.
The press gallery itself is a working office floor with a higher density than the general departmental floor — journalists, producers, camera operators and IT support staff packed into a confined working zone, plus the equipment racks for the broadcast feeds. Ventilation is sized at 12 L/s per person to account for the higher density. The acoustic target is NC 35 for general working space and NC 30 for the editing suite and recording booth. The supply ductwork is galvanised mild steel from the SBAL-V line.
The media briefing room itself carries an NC 25 acoustic target to support broadcast audio, a high lighting load from broadcast cameras and a dedicated AHU branch with its own VAV terminal. The supply diffusers are slot type concealed in the ceiling, the return is ducted, and the lined branch ensures the room is acoustically clean during a televised press conference.
Zone 8 — the public gallery
Every parliamentary chamber has a public gallery from which members of the public observe the debates. The federal Senate and House of Representatives public galleries seat several hundred each, with school groups and visitors cycling through the building continuously during a sitting week. The state chambers carry smaller galleries, scaled to the chamber. The public gallery sits inside the security envelope — visitors pass through a screening point on entry — but is functionally a high-occupancy public space.
The mechanical brief is 10 L/s per person ventilation, AS 2107 at NC 30 to keep the public gallery quiet enough to follow the chamber audio, dedicated supply and return paths separate from the chamber to keep acoustic and pressure isolation, and a cascade running slightly negative against the chamber to keep the chamber audio from leaking out into the public space. The gallery has a higher infiltration rate than the chamber because of the door cycling as visitors enter and leave. SBKJ supplies galvanised mild steel duct for the gallery from the SBAL-V line, with acoustic lining on the branch run.
Zone 9 — the parliamentary library, Hansard and the records archive
The Parliamentary Library at Australian Parliament House supports the research and information needs of senators and members. The state parliamentary libraries serve the same function at Macquarie Street, Spring Street and the equivalents. The Hansard office records the proceedings of the chamber, transcribes them and publishes the official record. Behind the library and Hansard sit the records archives — collections of historical material that must survive a 50 to 100 year preservation horizon.
The library reading room carries an AS 1668.2 ventilation rate at 10 L/s per person, AS 2107 acoustic at NC 30 and a setpoint of 22 °C at 50% relative humidity. The stack zones where books are held operate at the preservation envelope — 18 to 22 °C and 45 to 55% relative humidity — with tight tolerance to keep paper-based collections stable across decades. The acoustic target on the stack zone is NC 30 to allow research work in proximity to the collection. The mechanical detail follows the SBKJ library, museum and archive HVAC duct guide.
The Hansard office is an acoustic-sensitive recording space at NC 25 with isolated supply and return, dedicated to keeping the transcription audio clean. The records archive runs at the preservation envelope with HEPA filtration on the supply AHU and a tight humidity tolerance. SBKJ supplies the duct for these zones in galvanised mild steel from the SBAL-V line, with acoustic lining on the Hansard branch and tight-tolerance fabrication on the archive zone.
Zone 10 — the heritage envelope
Australian Parliament House on Capital Hill, opened in 1988, is heritage-listed. Old Parliament House in Canberra, which housed the federal parliament from 1927 to 1988 and now operates as the Museum of Australian Democracy, is heritage-listed. The state parliaments at Macquarie Street Sydney, Spring Street Melbourne, George Street Brisbane, St Georges Terrace Perth, North Terrace Adelaide and Salamanca Hobart are heritage-listed. A number of departmental buildings of architectural significance — including the Treasury Building Canberra, the Department of Defence Russell Hill, the East Block and West Block on Capital Hill, and the Edmund Barton Building — carry heritage controls.
Heritage controls translate into mechanical constraint. Visible ductwork is restricted or prohibited. Surface penetrations through heritage walls and ceilings are restricted or prohibited. New plant penetrations through the heritage building envelope are restricted. The mechanical engineer must route the ductwork through structural voids, use concealed slot diffusers integrated into the heritage joinery, locate access panels on the non-heritage face of the partition, and document the heritage scope for the local heritage council and the National Heritage Council.
The duct configuration for a heritage envelope drops the visible cross-section, raises the local face velocity within the heritage acoustic limits, and uses sealed-seam construction throughout to keep the leakage class tight so the concealed run does not leak out into the heritage cavity. SBKJ produces the heritage-grade duct on the SBAL-V line with TDF20 or higher leakage class, with all transitions welded by the SB-ZF1500 stitchwelder, and with the production cell configured to handle the smaller branch dimensions that fit inside the heritage void. The SBKJ heritage building renovation HVAC duct guide covers the broader heritage methodology.
Zone 11 — the lobby, the reception and the public counter
Every federal and state government building has a public face. At Parliament House, the marble foyer and the visitor reception. At a departmental building, the reception lobby and the visitor management desk. At a Services Australia, ATO or equivalent shopfront, the public counter. At Australian Border Force, Passport Office and equivalent identity-verification counters, a screened public counter with a security envelope behind it. At Service NSW, Service Victoria and the state equivalents, the public-facing service centre.
The lobby and reception operate at high occupancy and high infiltration due to door cycling. Ventilation is sized at 10 L/s per person. The acoustic target is NC 35 to NC 40. The cascade runs neutral or slightly negative against the back-of-house office to keep outside air from migrating into the secured working zone. The supply ductwork is galvanised mild steel from the SBAL-V line.
The public counter adds two requirements. First, the back-of-house office behind the counter is a working zone and runs slightly positive against the counter, with the counter zone slightly negative against the lobby. The pressure cascade enforces airflow direction across the security envelope. Second, the supply AHU carries MERV 13 filtration to protect the back-of-house personnel from airborne contamination, and the return path from the counter is dedicated, not shared with the back-of-house return. SBKJ supplies the public counter duct in galvanised mild steel from the SBAL-V line, with acoustic lining on the branch run to keep the working zone quiet during high-traffic periods.
Zone 12 — the holding cell and the secure custody zone
Many federal and state government buildings include a holding cell or secure custody zone. The Federal Court of Australia at Queens Square Sydney and the Owen Dixon Commonwealth Law Courts Melbourne hold detainees prior to court appearance. The Australian Federal Police Edmund Barton Building holds persons in custody. The Australian Border Force operational facilities at major airports hold persons under immigration detention. Some state government buildings include short-term holding for police custody or court custody.
The mechanical brief for a holding cell follows AS 4072.1 Class C secure construction principles. Sealed-seam ductwork, 96 mm anti-contraband mesh on every duct penetration, no accessible return air boots, welded-back joints on every branch take-off inside the custody envelope, and a six air change per hour minimum with the supply at 10 L/s per detainee. The pressure cascade runs the holding cell most negative in the building, drawing air from the secure transport corridor through the cell and to a controlled relief shaft. The supply AHU carries HEPA filtration where the custody zone handles persons with communicable disease risk. SBKJ produces holding cell duct in 304 stainless from the SBAL-V line with a coil change, with welded joints by the SB-ZF1500 stitchwelder. The SBKJ courthouse and court HVAC duct guide covers the broader custody methodology.
Zone 13 — the classified server room and the sovereign HCF data centre
Government IT spaces fall on a spectrum from a small comms room serving a single departmental floor up to a full sovereign HCF certified data centre that hosts classified workloads. The certification regime is the Hosting Certification Framework administered by the Department of Home Affairs, which classifies cloud and data centre providers as Certified Strategic, Certified Assured or Certified. The federal government places classified and high-impact workloads only in Certified Strategic facilities, with progressively lower classifications moving down the certification scale. Public information lists AWS Australia (Sydney and Melbourne), Microsoft Azure Australia Central (Canberra, the dedicated government region), Google Cloud Australia (Sydney and Melbourne), NEXTDC, Macquarie Government, StackCT, Sovereign Cloud Australia and Vault Cloud as participants at various levels of the HCF.
Inside a federal departmental tenancy, the classified server room is built against ASHRAE Class A2 or A3 thermal envelope (typically 18 to 27 °C dry bulb at the IT inlet), 8% to 80% relative humidity with tight dewpoint control, hot aisle and cold aisle containment, redundant CRAC units to N+1 minimum, redundant supply to the chilled water plant, and a comprehensive smoke and fire detection system with gaseous suppression where the room holds particularly sensitive equipment under AS 4214 or wet sprinkler under AS 2118 where the load is less sensitive. The ductwork supports the air-side distribution, return path to the CRAC and the fire and smoke management overlay.
Where the server room handles classified material it is also TEMPEST shielded with isolated mechanical services. The shielded envelope follows the same principles as the SCIF — small penetrations, anti-tamper grilles, vibration-isolated transitions, dedicated AHU branch, no shared returns. The duct material is stainless steel sealed-seam for the shielded portion and galvanised for everything outboard.
SBKJ produces the server room duct on the SBAL-V line with the SBSF-1525 for the smaller branch runs and the SBFB-1500 spiral former for the return risers serving a multi-storey installation. For the TEMPEST shielded portion, the coil changes to 304 stainless and the SB-ZF1500 stitchwelder takes the welded joints. The SBKJ data centre HVAC duct manufacturing guide covers the broader data centre methodology.
Zone 14 — the UPS battery room, the generator room and the diesel storage
Every major government building carries a backup power system. The UPS battery room holds the uninterruptible power supply that bridges a mains outage until the standby generator starts. The generator room holds the diesel standby generator that takes the load during an extended outage. The diesel storage tank holds the fuel that runs the generator. All three zones carry distinct mechanical and hazardous area requirements.
The UPS battery room is a hazardous area where the battery technology is lead-acid — the charging process releases hydrogen, which is flammable at 4% concentration in air. AS/NZS 60079 classifies the space as Zone 2, and the extract ventilation must keep the hydrogen concentration below 25% of the lower explosive limit at all operating points. Practical extract rates run at 12 air changes per hour minimum, with the extract running continuously when the batteries are charging and switching to a higher rate during equalisation charges. The extract ductwork must be spark-resistant — typically aluminium or special grade galvanised steel with bonded earth and AS 3000 compliant wiring on every motorised damper and exhaust fan.
The generator room handles combustion air on the supply side and engine exhaust on the discharge side. The combustion air rate runs at typically 8 to 10 m³/s at full generator load. The engine exhaust runs through a separate duct to a discharge stack above the building roof, with the exhaust temperature high enough to require stainless steel construction and the duct run sized to keep the back-pressure within the engine manufacturer's specification. AS 1940 governs the diesel storage tank and the fuel transfer system.
SBKJ supplies spark-resistant duct on the SBAL-V line in a dedicated configuration with all internal seams sealed, an external bond strip applied per AS/NZS 60079, and the duct material in aluminium alloy or special grade galvanised. The generator exhaust duct is supplied in 304 stainless from the same line with a coil change, with welded joints by the SB-ZF1500 stitchwelder. The combustion air supply duct is in galvanised mild steel as standard.
Zone 15 — the dignitaries residence and the helicopter pad
The Lodge in Canberra is the official Canberra residence of the Australian Prime Minister. Kirribilli House in Sydney is the official Sydney residence. The state premier residences and gubernatorial residences operate at the equivalent state level — Government House Sydney, Government House Melbourne and the equivalents. These residences carry a domestic mechanical brief overlaid with a security overlay (PSPF Zone 4 or Zone 5 depending on the function) and a heritage overlay (most of these residences are heritage-listed).
The mechanical brief is residential in form — ducted reverse-cycle distribution with zoning by room, ventilation sized for the residential occupancy plus state visitor capacity, AS 2107 at NC 30 for the bedrooms and study, AS 2107 at NC 35 for the dining and reception rooms. The ductwork is galvanised mild steel and concealed throughout. The security envelope holds at the staff and protective service entrances. The duct penetrations through the heritage envelope are concealed within structural voids.
The helicopter pad — where present — carries an AS/NZS 60079 Zone 2 classification around any aviation fuel storage. Where the pad is on the roof of a government building, the building HVAC system carries no direct relationship with the pad operations, but the rooftop plant room and the fuel storage area carry AS/NZS 60079 spark-resistant ductwork. The pad lighting circuit and the refuelling apron are designed by the aviation services contractor.
Zone 16 — the worker change room and amenity zone
Government buildings serving cleared zones include worker change facilities separated by security clearance level. The cleared installer crew, the cleared cleaning team and the cleared catering staff each access change rooms and amenity zones with the appropriate security envelope. The HVAC brief is conventional — AS 1668.2 ventilation, AS 2107 acoustic, NC 40 acceptable, and the supply ductwork in galvanised mild steel from the SBAL-V line.
The security overlay adds that the change room and amenity zone for the cleared crew is inside the secure envelope, with its own pressure regime and no commingling with the public-facing amenity. The cleared crew accesses the change room from the secure side and accesses the building from the secure side. The duct routing keeps the supply and return paths inside the secured envelope.
The pressure cascade in a federal government building
The pressure cascade in a federal government building is more complex than a commercial office tower because there are more zones and the security envelope binds harder. The hierarchy, from most positive to most negative, runs as follows. The cabinet room, SCIF and Restricted Zone Class A holdings at plus 12.5 to plus 15 Pa against their anterooms. The anterooms slightly positive against the corridor. The executive and senior officials private offices neutral against the corridor or slightly positive. The general open plan neutral. The corridor neutral or slightly negative against the secure zones. The public counter and lobby slightly negative against the back-of-house office. The holding cell most negative in the building, drawing air from the secure transport corridor. The UPS battery room runs at a controlled exhaust regime under AS/NZS 60079, not a fixed pressure setpoint.
The VAV terminals on each AHU branch hold the cascade. The commissioning team verifies the cascade with calibrated pressure sensors at the door of every secure zone before fit-off, with a documented commissioning record for the cleared contractor. The cascade is re-validated annually as part of the AS 1851 fire damper inspection cycle and the PSPF building security review.
The acoustic constraint
The acoustic targets across a federal government building span from NC 25 in the cabinet room and SCIF to NC 40 in the public counter and lobby. The targets bind the duct sizing in ways that the commercial office standard does not anticipate. The face velocity at supply diffusers in the cabinet room must stay below 1.5 m/s. The face velocity at return registers must stay below 1.2 m/s. The trans-duct break-in attenuation must be sufficient that the recording specification is met — chamber audio, cabinet record and SCIF compartmented record all carry distinct recording requirements that drive the trans-duct specification.
The acoustic lining on the branch run extends over the last three to five metres of the supply branch into a secure zone, with the lining specified for the frequency range that matches the room recording target. The supports are vibration-isolated at every transition to keep structural-borne audio out of the duct. The return air path uses ducted construction, not shared plenum, to keep audio cross-talk from leaking from one secure zone to another.
SBKJ supplies the duct with acoustic lining inserted in the manufacturing cell, with the lining specification matched to the recording target. The lined duct dispatches from Box Hill North VIC as part of the same batch as the unlined general office duct. The cleared installer crew receives a coordinated delivery.
Fire and smoke management
The federal government building falls under the NCC fire and smoke management overlay, with AS 1530.4 fire resistance of duct penetrations, AS 4072.1 fire-rated barrier construction, AS 4072.3 fire-rated smoke barrier construction, AS 1851 fire damper inspection cycle and AS 1668.1 smoke management. The cabinet room, SCIF, classified server room and Restricted Zone all sit inside fire-rated envelopes that must hold integrity during a fire event without compromising the security envelope. The fire damper at every secure zone penetration carries both a fire integrity rating and a tamper-resistant access panel.
Gaseous fire suppression under AS 4214 applies to the classified server room where the equipment is too sensitive to tolerate sprinkler discharge. The gaseous system uses inert gas or fluorinated agent flooding, with the suppression release coordinated with the HVAC shutdown so the agent is not extracted by the AHU before it reaches design concentration. The HVAC and the suppression system interlock at the controls level, with the duct dampers slamming closed on suppression release.
Sprinkler protection under AS 2118 applies to the general office, the public counter, the lobby, the corridor and the back-of-house zones. The sprinkler heads coordinate with the supply diffusers at the architectural ceiling so the suppression spray pattern is not obstructed by the duct geometry. The fire damper inspection cycle under AS 1851 runs annually with a documented record kept for the building manager and the fire authority.
The Hosting Certification Framework and the sovereign cloud landing zone
Federal agencies place classified and high-impact workloads only in Hosting Certification Framework (HCF) Certified Strategic facilities. The HCF, administered by the Department of Home Affairs, classifies data centre and cloud providers as Certified Strategic (highest), Certified Assured, or Certified. Public information lists AWS Australia (Sydney and Melbourne), Microsoft Azure Australia Central (Canberra, the dedicated government region), Google Cloud Australia (Sydney and Melbourne), NEXTDC at the HCF level, Macquarie Government, StackCT in Canberra, Sovereign Cloud Australia in Canberra and Vault Cloud in Canberra as participants at various levels of the HCF.
Where a federal agency stands up a tenancy in a sovereign cloud landing zone, the agency typically retains some on-premise classified server capacity inside the departmental building for the most sensitive workloads. The on-premise classified server room is built against the principles of the SCIF or Restricted Zone Class A holding — TEMPEST shielded, isolated mechanical services, redundant CRAC, hot aisle containment, gaseous suppression. The off-premise tenancy in the sovereign cloud handles the lower-classification workloads at HCF Certified Assured or Certified.
The mechanical brief for the on-premise classified server room follows the same approach as the SCIF in this guide. The mechanical brief for the off-premise tenancy in the sovereign cloud landing zone follows the SBKJ data centre HVAC duct manufacturing guide — the sovereign data centre is operationally a high-grade data centre with the HCF certification overlay.
The Defence Industry Security Program (DISP)
Where the federal facility supports Defence personnel or Defence work, the Defence Industry Security Program clears the principal contractor and the installer crew before they access the envelope. The DISP runs across four membership levels, with the higher levels carrying progressively heavier vetting and ongoing reporting obligations. The mechanical services contractor and the duct fabricator both need DISP membership at the appropriate level to access the secure construction site.
The DISP overlay adds three operational requirements on top of the conventional mechanical brief. The crew on site is vetted and badged. The fabrication facility is documented and the chain of custody log on every fitting is maintained from coil change at the production cell to commissioning at the building. The disposal of off-cuts and scrap is documented and the off-cuts do not leave the secure precinct in a public waste stream. SBKJ delivers all three under standard practice for the Defence projects — the documented chain of custody is part of the dispatch documentation, the off-cuts are returned to the secure precinct or destroyed under the cleared contractor's protocol, and the production cell at Box Hill North VIC supports the DISP audit cycle.
Heritage protection at Australian Parliament House and the state parliaments
Australian Parliament House on Capital Hill, designed by Mitchell, Giurgola & Thorp and completed in 1988, is heritage-listed under the National Heritage List. Old Parliament House in Canberra, opened in 1927, is heritage-listed at the highest level. The state parliaments at Macquarie Street Sydney (1816), Spring Street Melbourne (1856), George Street Brisbane (1868), the Perth complex on St Georges Terrace, the North Terrace Adelaide building (1855-89) and the Salamanca Hobart building are all heritage-listed under state legislation.
The mechanical engineer working on any of these envelopes coordinates with the heritage architect, the heritage council and the building services authority. The duct routing follows structural voids, the supply diffusers integrate into the heritage joinery, the access panels locate on non-heritage faces, and the new plant penetrations through the heritage envelope are restricted to existing service apertures. The duct fabrication carries tighter dimensional tolerances than the commercial standard to fit the concealed run. SBKJ supplies the heritage-grade duct on the SBAL-V line with TDF20 leakage class, welded transitions by the SB-ZF1500 stitchwelder and the production cell configured for the smaller branch dimensions.
The state parliament case — Macquarie Street, Spring Street, George Street and equivalents
The NSW Parliament at Macquarie Street Sydney occupies a heritage envelope dating from 1816 with later additions. The complex includes the Legislative Assembly chamber, the Legislative Council chamber, ministerial offices, committee rooms, members' lounges, public galleries, the parliamentary library, the press gallery and a heritage entrance hall. The mechanical brief overlays AS 1668.2 ventilation, AS 2107 acoustic and the NCC Class 5 office classification onto the heritage envelope, with concealed ductwork routing, slot diffusers integrated into heritage joinery and dedicated AHU branches for the chambers.
The Victorian Parliament at Spring Street Melbourne occupies a heritage envelope completed in stages from 1856, with the Queen's Hall, the chambers, the library, the members' dining room and the committee rooms inside the listed building. The cabinet suite operates within the precinct. The mechanical brief carries the same overlay as Macquarie Street.
The Queensland Parliament at George Street Brisbane is unicameral, with the Legislative Assembly as the single chamber. The 1868 building carries heritage controls. The Annex addition houses ministerial offices and meeting rooms. The mechanical brief overlays AS 1668.2 onto the heritage envelope and runs the cabinet suite as a discrete secure zone.
The Western Australian Parliament on Harvest Terrace Perth, the South Australian Parliament on North Terrace Adelaide and the Tasmanian Parliament on Salamanca Place Hobart each carry their own heritage and security overlays scaled to the state. The ACT Legislative Assembly in central Canberra and the Northern Territory Legislative Assembly in Darwin are more modern, unicameral chambers.
SBKJ supplies duct for state parliament projects on the same SBAL-V production line as the federal work, with the heritage configuration applied at the production cell. The state parliament cleared installer crew receives the batch under the same chain of custody as the federal projects.
The Australian Defence Force Russell Hill complex
Russell Hill in Canberra hosts the head office complex of the Department of Defence, the Australian Defence Force headquarters and supporting agencies. The general administrative floors look like a federal office tenancy — AS 1668.2 ventilation, AS 4254 ductwork, NCC Class 5 — but the building also hosts classified planning rooms, secure briefing facilities, communications spaces, an operations floor and supporting Restricted Zones.
The mechanical brief therefore overlays the PSPF, ASIO T4 and the DISP onto a conventional commercial office envelope. The result is two parallel duct streams — a galvanised general office stream and a stainless TEMPEST stream — and a cleared installer crew that handles both. The SBKJ defence and military HVAC duct guide covers the broader Defence methodology, including the Defence Science and Technology Group (DSTG) sites at Edinburgh SA and Fishermans Bend VIC, the Defence ranges at Williamtown NSW, Holsworthy NSW, Larrakeyah NT and Bonegilla VIC, and the operational ADF installations across the country.
The Ben Chifley Building (ASIO HQ)
The Ben Chifley Building at Parkes in Canberra is the head office of the Australian Security Intelligence Organisation, opened in 2013. From publicly available descriptions, the building combines general administrative space, briefing rooms, intelligence operations floors, communications rooms, server farms, an auditorium, training spaces and Restricted Zone Class A holdings.
The general administrative floors are built against AS 1668.2 and the NCC Class 5 office standard. Restricted Zone Class A holdings are TEMPEST shielded with isolated mechanical services. The communications and operations floors use a sovereign HCF certified server room standard with redundant AHUs and ASHRAE Class A2 or A3 thermal envelopes. The auditorium and briefing rooms add NC 25 acoustic. Every duct penetration is documented under the PSPF, and the construction is delivered by a DISP cleared contractor. The mechanical brief therefore needs three duct material streams from a single production cell — galvanised general office, stainless steel secure plenum, and acoustically lined briefing duct.
Equivalent intelligence community buildings — the Australian Secret Intelligence Service Canberra headquarters, the Australian Signals Directorate Canberra headquarters, the Office of National Intelligence Canberra headquarters — carry similar mechanical briefs scaled to the agency's footprint.
The Australian Federal Police Edmund Barton Building
The Edmund Barton Building in Canberra houses the head office of the Australian Federal Police, plus other Commonwealth agencies. The AFP component includes general administrative floors, operational command centres, communications and signals intelligence rooms, holding cells, evidence storage, firearms armoury, training spaces and meeting rooms. State and territory police equivalents — NSW Police Force at Parramatta, Victoria Police Centre at Spencer Street Melbourne, Queensland Police HQ at Roma Street Brisbane — carry the same broad brief at the state level.
The mechanical envelope follows AS 1668.2 for the general administrative space, AS 4072.1 Class C for the holding cell and evidence storage, AS 4214 gaseous suppression for the signals intelligence and operational command rooms, and TEMPEST shielding for the classified planning rooms. The duct material splits between galvanised general office, stainless steel secure plenum and spark-resistant for the firearms armoury cleaning area where solvent vapour management is required.
The Australian Border Force operational facilities
The Australian Border Force operates from a head office in Canberra and from operational facilities at major airports — Sydney Kingsford Smith, Melbourne Tullamarine, Brisbane, Perth, Adelaide, Cairns — and at major seaports including Port Botany, Port Melbourne, Port of Brisbane, Fremantle, Port Adelaide and Townsville. The operational facilities combine the airside passenger processing area, a back-of-house officer working zone, the holding cell for immigration detention, the secure evidence storage, the communications and intelligence room, and the public-facing primary line booths.
The mechanical brief overlays AS 1668.2 ventilation, AS 4072.1 Class C secure construction for the holding cell and secure evidence room, AS 2107 acoustic at NC 35 for the primary line and NC 30 for the secondary inspection room, and TEMPEST shielding for the classified intelligence room. The duct material splits between galvanised general office, stainless steel secure plenum and a specialised stainless for the secondary inspection area where biological sample handling occurs.
The airport operational facility integrates with the broader airport mechanical envelope — see the SBKJ airport HVAC duct guide for the airport context. The ABF tenancy inside the airport carries its own duct material specification and pressure cascade.
The Federal Court and the High Court
The Federal Court of Australia operates from court facilities in Sydney (Queens Square), Melbourne (Owen Dixon Commonwealth Law Courts), Brisbane (Harry Gibbs Commonwealth Law Courts), Perth (Peter Durack Commonwealth Law Courts), Adelaide, Canberra, Darwin and Hobart. The High Court of Australia operates from its purpose-built facility on the Parliamentary Triangle in Canberra, opened in 1980. The Family Court and the Administrative Appeals Tribunal operate from similar facilities across the country.
The court mechanical brief follows the SBKJ courthouse and court HVAC duct guide — courtroom, jury room, witness room, judge chambers, public gallery, custody holding cell, transport corridor, secure dock and records archive zones, all built against AS 1668.2, AS 2107, AS 4072.1 and the relevant ASHRAE Applications Handbook chapter. The court component of a federal building draws the courthouse brief into the broader government brief; the engineer reads both guides together.
The dignitaries residence — The Lodge and Kirribilli House
The Lodge in Canberra is the official Canberra residence of the Australian Prime Minister, completed in 1927. Kirribilli House in Sydney is the official Sydney residence, dating to 1855. The state Government Houses — Government House Sydney (1843), Government House Melbourne (1872), the equivalents in Brisbane, Perth, Adelaide and Hobart — serve as the gubernatorial residences. The state premier residences operate at a scaled-down equivalent of the Lodge.
The mechanical brief is residential in form, with ducted reverse-cycle distribution, zoning by room, AS 1668.2 ventilation for the residential occupancy plus state visitor capacity, AS 2107 acoustic at NC 30 for the bedrooms and study and NC 35 for the dining and reception. The ductwork is galvanised mild steel concealed throughout. The security envelope holds at the staff and protective service entrances. The duct penetrations through the heritage envelope are concealed within structural voids. SBKJ supplies the residence duct in galvanised from the SBAL-V line, with the heritage configuration applied at the production cell.
The cleared installer and the chain of custody
The cleared installer crew receives the SBKJ batch under a documented chain of custody. The chain of custody log starts at the coil change in the production cell, records the heat number on every fitting, records the welding procedure on every joint, records the QA hold point at the production cell and at the dispatch hold point, records the seal on the shipping container, records the destination handover, and closes at the building commissioning sign-off. The cleared contractor maintains the log for the building manager and the security authority.
This chain of custody is part of the operational practice for any federal building project that touches a Restricted Zone, a SCIF, a CIF, a cabinet room, a classified server room or a Defence facility. The DISP audit cycle reviews the chain of custody log on a periodic basis. The PSPF building security review reviews the duct construction class against the security zone classification. The AS 1851 fire damper inspection cycle reviews the fire damper integrity. The annual ISM review reviews the TEMPEST envelope integrity.
SBKJ supports each of these review cycles with the dispatch documentation, the production cell records, the material certificates and the welding procedure records. The cleared installer crew receives a complete documentary package with every batch.
The Department of Finance Australian Government Property Group
The Department of Finance Australian Government Property Group manages the Commonwealth's office accommodation portfolio — the network of owned and leased buildings that house federal departments and agencies. The portfolio sits on top of a property strategy that consolidates departmental tenancies into shared buildings where practical, refreshes the workplace fitout on a defined cycle and aligns the property footprint with government policy.
For the mechanical services supplier, the Australian Government Property Group is the procurement counterparty on a range of federal fitout projects. The standard procurement model uses a head contractor — typically one of Lendlease ASX:LLC, John Holland (CIMIC), Multiplex (Brookfield), Built (Lendlease), Hutchinson Builders, Doma Group, Stack Group or Construction Control on Canberra projects, or Capella Capital and Plenary Group on PPP projects — with the mechanical services contractor as a subcontractor and the duct fabricator under the mechanical services contractor. SBKJ engages the supply chain at the duct fabricator level.
State equivalents include Property NSW, the Department of Treasury and Finance Victoria, the Queensland Building and Construction Commission QBCC, the State of NSW Property authority, the Building Commission Victoria and the Hesperia state property entity in Western Australia. Each operates a parallel property portfolio with parallel procurement and parallel mechanical services briefs.
Australian engineering, Australian dispatch, the SBKJ production cell
The SBKJ Group production cell at Box Hill North VIC produces the entire federal and state government duct portfolio from a single line, with coil changes at the production cell to switch between galvanised general office, stainless TEMPEST plenum and spark-resistant aluminium or special grade galvanised for the hazardous area. The line is the SBAL-V auto duct line, configured for the multi-material workflow and supported by the SB-ZF1500 stitchwelder for the welded stainless joints, the SBSF-1525 for the smaller branch runs, the SBFB-1500 spiral former for the multi-storey return risers, the SBPC1500 plasma cutter for the shaped penetrations and the SBLR-600 welder for the larger transitions.
Every batch dispatches from the Box Hill North VIC office as a single coordinated delivery, with the full chain of custody documentation, the material certificates, the heat number trace, the weld procedure records and the QA hold point records. The cleared installer crew receives the batch under documented handover. The 12-hour engineering reply on every quotation comes from a senior SBKJ engineer, not a salesperson — the engineering team understands the federal and state procurement model, the PSPF zoning, the ASIO T4 technical requirements, the DISP clearance regime, the ISM TEMPEST envelope and the AS 4072.1 fire-rated penetration discipline.
Machinery configuration — the SBKJ recommendation for a federal government project
For a typical federal departmental fitout combining general office, executive suite, cabinet-grade secure briefing, SCIF, classified server room, UPS battery room and generator room, SBKJ recommends the following machinery configuration. The SBAL-V auto duct line is the workhorse, producing the galvanised general office duct in Z275 coating at TDF20 leakage class and the stainless TEMPEST plenum in 304 stainless steel with sealed-seam construction. The coil change between materials is a documented step in the production cell. The SB-ZF1500 stitchwelder handles the welded stainless joints for the SCIF, the cabinet room plenum and the secure briefing room. The SBSF-1525 small duct line handles the smaller branch runs that fit into the heritage void and the concealed plenum runs above the executive offices. The SBFB-1500 spiral duct former produces the return risers for the multi-storey installations and the round duct sections for the chamber distribution. The SBPC1500 plasma cutter handles the shaped penetrations and the custom hole patterns for the TEMPEST grilles. The SBLR-600 welder handles the larger site-welded transitions for the chamber risers and the auditorium plenums.
For the UPS battery room and the generator combustion air, the SBAL-V line runs in spark-resistant configuration with aluminium alloy or special grade galvanised coil, with all internal seams sealed and an external bond strip applied per AS/NZS 60079. The generator exhaust duct in 304 stainless from the same SBAL-V line with welded joints by the SB-ZF1500.
The single coordinated batch dispatches from Box Hill North VIC with the full chain of custody documentation. The principal mechanical services contractor takes delivery of a single batch and installs it through the cleared installer crew with on-site commissioning supervised by the SBKJ engineering team.
For the smaller federal projects — a regional ATO office, a Department of Veterans' Affairs tenancy in a leased suburban office, a Department of Social Services back-of-house in a regional capital — the configuration scales down to the SBAL-V line alone, with galvanised general office duct only. The Restricted Zone components are typically absent from these smaller projects, and the procurement runs through the standard commercial mechanical services contracting model.
Working with the Canberra-focused contractors
Several mechanical services contractors and head contractors maintain a Canberra-focused practice with deep experience in the federal estate. Doma Group, Stack Group and Construction Control all maintain Canberra offices and run continuing portfolios of federal projects. Lendlease and John Holland (CIMIC) maintain national practices with significant Canberra delivery capacity. Multiplex (Brookfield), Built and Hutchinson Builders all carry federal credentials. For Public-Private Partnership delivery models, Capella Capital and Plenary Group structure the PPP and bring the head contractor and the mechanical services supply chain to the project — the Royal Adelaide Hospital PPP and similar federal-state hybrid projects sit in this category.
SBKJ engages these contractors as the duct fabrication subcontractor in the mechanical services chain. The 12-hour engineering reply, the documented chain of custody, the multi-material production cell at Box Hill North VIC and the dispatch documentation align with the contracting model these head contractors run on federal projects. The cleared installer crew — whether engaged directly by the head contractor or by the mechanical services contractor — receives the SBKJ batch under documented handover with full documentation.
Industry bodies and the broader policy environment
The Property Council of Australia (PCA) speaks for the commercial property sector and engages the federal Department of Finance on the office accommodation policy. The Australian Strategic Policy Institute (ASPI) publishes on Defence and strategic policy and informs the broader industry view on Defence infrastructure. The Australian Defence Industry Capability framework (ADIC) shapes the Defence industry policy that flows down to the contractor and subcontractor base. The Australian Cyber Security Centre (ACSC) issues the Information Security Manual and engages the industry on cyber and emissions security.
The mechanical services supplier reads these policy bodies for the trend signals on government investment in the building portfolio, the Defence infrastructure footprint and the sovereign cloud landing zone. The trend signals translate into the procurement pipeline that the SBKJ Group production cell at Box Hill North VIC supports.
Commissioning, balancing and the handover
The commissioning of a federal government building HVAC system runs across a structured sequence. The supply AHU is started and balanced to design flow at every diffuser. The return path is verified open and balanced. The pressure cascade is set with calibrated pressure sensors at the door of every secure zone. The acoustic performance is verified with a sound level meter at the cabinet room, the SCIF, the classified server room and the chamber. The fire damper integrity is verified with a smoke test at every damper. The TEMPEST envelope is verified with the emissions test sequence prescribed by the ISM. The chain of custody log is closed at the handover sign-off.
SBKJ supports the commissioning with the production cell records, the material certificates, the welding procedure records and the QA hold point records. The senior SBKJ engineer attends the site for the commissioning of the secure zone plenums where the cleared contractor requests engineering support. The 12-hour engineering reply window extends to the commissioning phase.
The recurring maintenance cycle
The federal government building runs an annual maintenance cycle. The AS 1851 fire damper inspection runs annually with a documented record. The AS 1668.1 smoke management system tests run annually. The TEMPEST envelope verification runs on a cycle prescribed by the ISM. The PSPF building security review runs on a cycle prescribed by the building security plan. The annual filter change at the supply AHU and the annual coil clean at the chilled water coil sit inside the standard mechanical maintenance schedule.
The cleared maintenance crew accesses the secure zones under documented entry. The chain of custody log carries forward across the maintenance cycle. The SBKJ engineering team supports the maintenance phase with replacement components produced on the same SBAL-V line, with material certificates and weld procedure records aligned to the original install.
The SBKJ position — one production cell, the full government brief
The SBKJ Group position on the federal and state government brief is straightforward. One Australian production cell, in Box Hill North VIC, runs the SBAL-V auto duct line and the supporting machines to produce the entire portfolio of duct material that a federal or state government project needs. Galvanised general office, stainless TEMPEST plenum, spark-resistant aluminium or special grade galvanised, acoustic-lined branch, heritage-grade tight-tolerance fabrication — all five duct streams produced on the same production cell, dispatched as a single coordinated batch with full chain of custody documentation, installed by the cleared contractor's installer crew under documented handover.
The 12-hour engineering reply on the quotation comes from a senior SBKJ engineer based at Box Hill North VIC. The engineer reads the floor plan, classifies the zones against the PSPF security schedule, identifies the heritage envelope, sizes the duct against AS 1668.2 and AS 2107, specifies the construction class against AS 4254 and AS 4072.1, configures the production cell for the multi-material workflow and dispatches the batch.
The federal procurement counterparties — the Department of Finance Australian Government Property Group, the state property authorities and the cleared head contractors — receive a single accountable supplier for the duct component of the mechanical services scope. The cleared installer crew receives a coordinated batch with full documentation. The PSPF, the ASIO T4 technical guidance, the ISM TEMPEST envelope and the DISP cleared contracting model all align with the SBKJ delivery practice.
Frequently asked technical questions
What is the acoustic target for the federal cabinet room?
The cabinet room operates at NC 25 under the AS 2107 acoustic schedule, which is well below the AS 2107 general office baseline of NC 35 to NC 40. The face velocity at supply diffusers stays below 1.5 m/s, the face velocity at return registers stays below 1.2 m/s, and the trans-duct break-in attenuation is specified to meet the recording target for the official cabinet record.
How does SBKJ document the chain of custody for a Defence project?
The chain of custody log starts at the coil change in the production cell at Box Hill North VIC, records the heat number on every fitting, records the welding procedure on every joint, records the QA hold point at the production cell and at the dispatch hold point, records the seal on the shipping container, records the destination handover and closes at the building commissioning sign-off. The log is part of the dispatch documentation. The cleared installer crew receives the log with the batch.
Which SBKJ machine produces the SCIF plenum?
The SCIF plenum is produced on the SBAL-V auto duct line with a coil change to 304 stainless steel, with welded joints by the SB-ZF1500 stitchwelder. The plenum dispatches as part of the same batch as the galvanised general office duct, with the documented chain of custody and the material certificate.
What is the typical lead time on a federal departmental fitout batch?
For a typical federal departmental fitout combining general office, executive suite, cabinet-grade secure briefing, SCIF, classified server room and UPS battery room, total production time is approximately 8 to 12 line shifts including coil changes and QA hold points. Dispatch from Box Hill North VIC is typically 14 to 21 days after final fabrication, including ISPM-15 fumigated crating where required by the destination site.
Does SBKJ deliver the duct to the secure construction site?
SBKJ dispatches the batch from Box Hill North VIC to the destination handover point. The destination handover point may be the head contractor's site office, the cleared installer crew's holding facility, or the secure construction site directly — depending on the chain of custody protocol agreed with the head contractor. The dispatch documentation carries forward to the destination handover.
What does SBKJ recommend for the press gallery duct?
The press gallery is a working office floor at higher density than the general departmental floor. SBKJ recommends Z275 galvanised mild steel from the SBAL-V line, with acoustic lining on the branch run for the editing suite and recording booth, sized at 12 L/s per person under AS 1668.2 and balanced to NC 30 for the editing suite and NC 35 for the general working space.
How does the cabinet anteroom differ from the cabinet room itself?
The cabinet anteroom sits between the corridor and the cabinet room, providing a secure transition for entry and exit during a cabinet meeting. The anteroom runs at slightly negative pressure relative to the cabinet room and slightly positive relative to the corridor, with ventilation at 10 L/s per person, AS 2107 acoustic at NC 30, and a dedicated supply branch separate from the cabinet room. The ductwork is galvanised mild steel, distinct from the stainless plenum serving the cabinet room itself.
What is the UPS battery room extract rate?
For a lead-acid UPS battery installation, AS/NZS 60079 requires extract ventilation to keep the hydrogen concentration below 25% of the lower explosive limit at all operating points. Practical extract rates run at 12 air changes per hour minimum, with the extract running continuously during charging and switching to a higher rate during equalisation. SBKJ supplies the extract duct in spark-resistant aluminium or special grade galvanised from the SBAL-V line, with bonded earth and AS 3000 compliant wiring on all electrical components.
Does the cabinet room kitchen share an exhaust with the general kitchen?
No. The cabinet room kitchen runs on its own exhaust to a separate discharge, with no commingling with the general office kitchen exhaust or the general office return air. The separation keeps food preparation noise and odour out of the cabinet room deliberative envelope. The exhaust duct is supplied in 304 stainless from the SBAL-V line with welded joints by the SB-ZF1500.
How does SBKJ handle the heritage configuration?
The heritage configuration runs on the SBAL-V line with TDF20 leakage class, tight dimensional tolerance to fit the concealed void above the heritage ceiling, welded transitions by the SB-ZF1500 stitchwelder and the smaller branch dimensions handled by the SBSF-1525. The duct routes through structural voids on site, with slot diffusers integrated into the heritage joinery and access panels on the non-heritage face of the partition. The heritage configuration applies at Parliament House Canberra, Old Parliament House, the state parliaments and the heritage departmental buildings.
Conclusion — the government brief rewards the disciplined supplier
The federal and state government building is among the most demanding mechanical services environments in the Australian construction sector. Five distinct duct material streams produced on one production cell. Five distinct security overlays applied to the same envelope. Five distinct acoustic targets bound by the recording specifications of the chambers, the cabinet room and the SCIF. Five distinct fire-rated and smoke-rated barrier classes coordinated with the security envelope. One cleared installer crew engaged through one head contractor on one project schedule.
The mechanical services brief that delivers this is the brief that treats the whole portfolio as one system, with a single accountable duct supplier delivering galvanised, stainless, spark-resistant, acoustic-lined and heritage-grade product from a single Australian production cell. The cleared contractor takes a single coordinated batch and installs it through the cleared crew, with the documented chain of custody intact from the coil change at Box Hill North VIC to the commissioning sign-off at Capital Hill, Russell Hill, Parkes, Macquarie Street, Spring Street or any of the other government precincts across the country.
The SBKJ SBAL-V auto duct line, configured for this multi-stream workflow and delivered through the SBKJ Group Box Hill North VIC dispatch facility, is the production cell that makes the brief economic and timely. The 12-hour engineering reply on the quotation comes from a senior SBKJ engineer who understands the federal and state procurement model, the PSPF zoning, the ASIO T4 technical requirements, the DISP clearance regime, the ISM TEMPEST envelope and the AS 4072.1 fire-rated penetration discipline. The principal mechanical services contractor takes delivery of a single coordinated batch and installs it through the cleared installer crew, with on-site commissioning supervised by the SBKJ engineering team and the chain of custody documentation closed at the building handover.
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