Building fabric
The building fabric is a home's thermal shell (walls, roof, floor, glazing) whose insulation and sealing the NatHERS rating and elemental DTS energy provisions assess.
Ask Chalkline about this →In energy-efficiency terms, the building fabric is the thermal shell of a building: the external walls, the roof and ceiling, the floor, and the glazing (windows and doors). It is the part of the building whose insulation, thermal mass, and air sealing determine how much heat moves in and out, and therefore how hard the heating and cooling has to work. For example, adding wall and ceiling insulation, double glazing, and draught sealing all improve the fabric; swapping the air conditioner does not.
Under NCC 2022, the fabric is what the NatHERS thermal rating and the elemental Deemed-to-Satisfy provisions assess: insulation R-values, glazing performance, and sealing. This is deliberately separate from the fixed appliances (hot water, heating and cooling, lighting, pool pumps) measured by the Whole-of-Home budget. The two work together: a new Class 1 home must pass both a fabric requirement (a minimum 7-star NatHERS rating, or BASIX in NSW) and a Whole-of-Home score.
A good fabric is usually the cheaper lever, because it cuts the heating and cooling load for the life of the building, not just until an appliance is replaced. Get the fabric wrong and no amount of efficient appliances will rescue the rating, because the NatHERS rating is a fabric measure. The most common cost hit is a late glazing change, which forces the thermal model to be redone, so lock the window schedule, insulation spec, and sealing details before the NatHERS model is finalised.
Also known as: Thermal envelope, building envelope, thermal shell.
Category: Energy efficiency / Building science.
Related
See also
References
- ABCB: NCC energy efficiency provisions (verified 2026-05-09)
- Nationwide House Energy Rating Scheme (NatHERS) (verified 2026-05-09)
Last updated: 2026-05-30. Verified: 2026-05-09. Quarterly review for currency.