Why a warehouse awning can count towards fire compartment volume

By Brenscot Builders | Last reviewed September 2026

An awning over the loading area looks like free weather protection. It has no walls, so most people assume it sits outside the building for compliance purposes. Under the National Construction Code (NCC) that is not a safe assumption. Depending on what happens underneath it, an awning can add to the building's measured floor area and volume, and on a warehouse that is already close to its limits, that can change the fire requirements for the whole building.

This article refers to NCC 2022 Volume One, which applies in Queensland until NCC 2025 commences on 1 May 2027.

The short answer

The NCC measures a fire compartment's floor area and volume within its walls, but where there is no wall, the measurement includes any area or space "which has a use which contributes to the fire load". An open-sided awning used for loading, staging pallets or storage can therefore be counted. The building certifier decides how the definition applies to your design, so raise it at concept stage.

Why it matters: the limits are tight

NCC Table C3D3 limits a fire compartment in a Type C warehouse (Type C is the construction type that applies to most single-storey warehouses) to 2,000 m2 of floor area and 12,000 m3 of volume. Exceed either and the building needs fire walls, a higher type of construction, the large isolated building provisions or a performance solution. See fire walls and fire compartments.

Tall warehouses reach the volume limit well before the floor area limit. Buildings are often designed close to the limit to maximise lettable area, so a small addition matters.

Worked example: a building 60 m long with an 8 m deep awning along one side at an average height of 6 m. If the awning is counted, it adds 60 x 8 = 480 m2 of floor area and 480 x 6 = 2,880 m3 of volume. That is almost a quarter of the entire 12,000 m3 allowance for a Type C compartment.

The same 2,000 m2 and 12,000 m3 figures are also the threshold in clause E1D13 above which an occupancy of excessive hazard needs sprinklers. See fire services.

What the NCC definitions say

The NCC's defined terms (Schedule 1) include:

• Floor area, in relation to a fire compartment: the total area of all floors within the fire compartment measured within the finished internal surfaces of the bounding construction, "and if there is no bounding construction, includes an area which has a use which contributes to the fire load".
• Volume, in relation to a fire compartment: the total space measured within the fire-resisting walls (or, where a wall is not fire-resisting, over the enclosing wall), from the lowest floor to the underside of the roof covering, and "if there is no enclosing wall, includes any space within the fire compartment that has a use which contributes to the fire load".

So the test is not whether the awning has walls. It is whether the space beneath it has a use that contributes to the fire load, meaning combustible material that would feed a fire.

We have not found published Australian Building Codes Board guidance that deals specifically with warehouse awnings. The interpretation sits with the building certifier on each project, and certifiers can differ. That is the reason to ask the question early and get the answer in writing.

When an awning is more likely to be counted

Treat these as prompts for a conversation with the certifier, not as rules:

1. Goods are stored or staged under it. Pallets waiting for collection, packaging, bins, stillages and stock all contribute fire load.
2. Work happens under it. Packing, assembly or processing extends the building's use into the space.
3. It is partly or fully enclosed. Side sheeting, mesh, roller doors or plastic strip curtains make it part of the building in every practical sense.
4. It is continuous with the main roof. A deep awning under the same roofline reads as an extension of the warehouse.
5. It is likely to be filled or enclosed later. A tenant who sheets in the sides or stacks goods beneath changes the basis of the approval.

An awning that only shelters a doorway or a vehicle while it is being loaded, with nothing stored beneath it, is easier to argue as not contributing. It remains the certifier's decision.

Awnings and large isolated buildings

If the building relies on the large isolated building provisions (clause C3D4), it needs either open space at least 18 m wide around it (which must include fire truck access, and is only available for buildings up to 18,000 m2 and 108,000 m3), or sprinklers with a continuous 6 m wide perimeter access path for fire trucks. Under clause C3D5 the open space must not be used for storage or processing and must not be built on, apart from guard houses and service structures, such as substations and pump houses, that don't unduly impede firefighting. An awning, or goods stored under one, within that space can compromise the pathway. Check awning locations against the perimeter access before the site layout is fixed.

Design moves that help

• Decide what the awning is for. Shelter over a door needs far less depth than all-weather staging for pallets.
• Count it from the start. Include the awning in the floor area and volume calculations at concept stage, and size the building to suit. It is easier to find later that you have spare capacity than to find you are over.
• Keep it open and keep it clear. If the compliance approach relies on the awning being open and free of storage, record that in the approval documents and the lease, so later occupants know.
• Watch the height. Volume is area multiplied by height. Lowering an awning reduces what it adds.
• Separate awnings between units. In multi-unit buildings, keep each unit's awning within that unit's fire compartment and don't run a continuous awning across the fire walls without resolving how the separation is maintained.
• Don't enclose it later without approval. Enclosing an awning is building work and changes the building's measured size. It needs a building approval.

Frequently asked questions

Do awnings count towards a warehouse's floor area under the NCC?

They can. For fire compartment purposes, the NCC includes unenclosed areas that have a use contributing to the fire load. Storage and staging of goods under an awning is such a use. The certifier decides for each building.

How is fire compartment volume calculated?

It is the total space within the compartment's walls, from the lowest floor to the underside of the roof covering. Where there is no enclosing wall, spaces with a use that contributes to the fire load are included.

Is fire compartment floor area the same as gross floor area?

No. Gross floor area is a planning term defined in the Planning Regulation 2017 and is used for planning assessment and infrastructure charges. It excludes areas such as parking, loading and vehicle manoeuvring. The NCC's floor area is a building term with a different definition. An awning can be treated differently under each.

Can I enclose an awning later?

Only with building approval. Enclosing it adds to the building's floor area and volume and may change fire, structural and planning compliance.

Does an awning need its own approval?

An awning built with the warehouse is part of the building approval. Adding one later is building work and needs approval, and it may need planning assessment if it changes site cover or setbacks.

Sources

• National Construction Code 2022, Volume One: Schedule 1 definitions of fire compartment, floor area and volume; clause C3D3 and Table C3D3; clauses C3D4 and C3D5; clause E1D13, ncc.abcb.gov.au
• Planning Regulation 2017 (Qld), Schedule 24, definition of gross floor area

General information only

This article is general information based on NCC 2022 Volume One, current as at September 2026. It is not design or certification advice. How floor area and volume are measured for your building, including the treatment of awnings, must be confirmed by your building certifier.

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