Which Buildings Need Section J? Classes 3 and 5 to 9

Short answer: Class 3 and Classes 5 to 9.

Section J is the energy efficiency part of NCC Volume One. Under NCC 2025, its Deemed-to-Satisfy route applies to a Class 3 to 9 building, with Class 4 parts handled by their own provisions. The ABCB lists hotels, offices, retail, hospitals and schools as typical examples.

Two groups sit outside it. Houses (Class 1) are in NCC Volume Two, Part H6. For apartment buildings (Class 2), NCC 2025 replaces Section J with Section J of NCC 2022 Amendment 2.

What each class means, in the ABCB's words.

Class 3

Residential buildings other than Class 1 houses or Class 2 apartments, or a Class 4 part of a building.

Class 5

Office buildings used for professional or commercial purposes.

Class 6

Typically shops, restaurants and cafes.

Class 7a and 7b

Class 7a is carparks. Class 7b is typically warehouses, storage buildings and buildings that display goods for wholesale.

Class 8

A building where a process or handicraft is carried out for trade, sale or gain. Factories and workshops.

Class 9a, 9b and 9c

Health-care buildings (9a), assembly buildings where people gather for social, theatrical, political, religious or civil purposes (9b), and residential care buildings (9c).

Mixed buildings

A minor use can take the main classification when it is not more than 10% of the floor area of the storey it is on. The ABCB's example: an office taking 8% of a warehouse floor lets the whole building be Class 7b; at 12% the office is classified separately.

What Section J actually covers.

NCC 2025 splits Section J into nine Parts. Parts J3 to J9 are the Deemed-to-Satisfy Provisions.

J1 Performance Requirements and Verification Methods.
J2 How the Deemed-to-Satisfy Provisions apply.
J3 Elemental provisions for a Class 4 part of a building.
J4 Building fabric: roofs, walls, floors and glazing.
J5 Building sealing.
J6 Air-conditioning and ventilation.
J7 Artificial lighting and power.
J8 Heated water supply and swimming pool and spa pool plant.
J9 Energy monitoring and on-site distributed energy resources.

For a Class 3 to 9 building, J2D2 says the main Performance Requirement, J1P1, is met by complying with Parts J4 to J8, J9D3 and J9D5(2) to (4). In NCC 2025, J9D5 is where the solar PV requirement sits.

Which parts a typical job touches.

New building

The full set: fabric and glazing, sealing, services, lighting, hot water, metering and solar.

Fitout with new lighting only

Often Part J7, the lighting power and controls, for the area being fitted out. The building surveyor confirms the scope.

Not sure which class the building is? The building surveyor decides, from the use on the drawings. Send the plans and we confirm what the report needs to cover. More on our Section J reports page.

Sources: ABCB, Building classifications; NCC 2025 Volume One, Section J, Part J1 and Part J2; NCC 2025 commercial energy efficiency changes. General information, not an assessment of any particular site.

Common questions

Does Section J apply to a warehouse?

Yes.

Warehouses are Class 7b, inside the Class 5 to 9 range that Section J covers.

An office inside the warehouse may need its own Class 5 classification if it is more than 10% of the storey's floor area.

Does Section J apply to apartments?

Under NCC 2025, Class 2 buildings use Section J of NCC 2022 Amendment 2 instead of the 2025 text.

So apartments still have Section J requirements, just from the 2022 edition.

Do houses need a Section J report?

No.

Class 1 houses are in NCC Volume Two and use Part H6, usually through a NatHERS rating.

That is a residential energy report, not Section J.

Is a carpark covered?

Class 7a carparks sit inside the Class 5 to 9 range.

The building surveyor confirms which Parts apply to the work.

Need a Section J report?

For builders, developers and architects with a Class 3 to 9 building: NCC 2025, 2022 or 2019, within 72 hours.

See the service

Which buildings does Section J apply to?