Sustainability and energy

5 October 2026

NCC Section J Energy Efficiency Explained: Performance Requirements, the DTS Parts J4 to J9, Section J Reports and Lighting Power (2025 Guide)

Section J of NCC 2025 Volume One sets the energy efficiency rules for Class 3 and Class 5 to 9 buildings and Class 4 parts. This guide covers the four Performance Requirements, the Verification Methods (NABERS Energy, Green Star, a reference building and an air-tightness test), the Deemed-to-Satisfy Parts J4 to J9 with their key numbers, what a Section J report is, and a checker for the J7D3 lighting power allowance.

5 October 2026

NatHERS 7 Star Rating and Whole-of-Home Explained: NCC 2025 Energy Requirements for New Houses (2025 Guide)

A new house on the NCC 2025 energy rating pathway needs a NatHERS rating of 7 stars, inside separate heating and cooling load limits, and a whole-of-home rating of 60 (Specification 42). In climate zones 1 and 2 a qualifying outdoor living area lowers the star rating to 6.5, or to 6 with a ceiling fan. This guide sets out both pathways in Part H6, the elemental route in Housing Provisions Section 13, the state and territory variations, and a checker for your ratings.

13 May 2025

Ventilated Rainscreen Facades and NCC Section J: Thermal Bridging, R-values and the Clauses That Apply

How a ventilated rainscreen wall works, why thermal bridging decides its real R-value, and where the requirements sit in NCC 2025: J4D3, J4D6 and Specification 37 in Section J, and F8D3 for condensation.