3. Insulation in large buildings
This section covers energy efficiency for large buildings greater than 300m squared other than housing.
On this page
The proposals in this section relate to ways to amend the Acceptable Solution H1/AS2 and Verification Method H1/VM2 to:
- Optimise insulation to better balance upfront building costs and longer-term benefits
- Improve the consistency and certainty of compliance and consenting of buildings regarding insulation requirements and energy efficiency.
In this section
3.1. Background on energy efficiency for large buildings
Pathways for the H1 energy efficiency insulation provisions for large buildings.
3.2. Optimising insulation to better balance upfront building costs and longer-term benefits
Key topics on optimising insulation to better balance upfront building costs and longer-term benefits.
3.3. Topic 12: The schedule method may lead to less cost-effective construction than the more flexible calculation and modelling methods
Proposing the removal of the schedule method.
3.4. Topic 13: The calculation method does not provide flexibility for roof, skylight and floor R-values, limiting opportunities for optimising insulation
Allowing flexibility for the R-values of all building elements in the calculation method.
3.5. Topic 14: Where underfloor heating is only used in bathrooms, the minimum R-values for heated floors may cause unreasonable upfront costs
Proposed change to exempt embedded heating solely used in bathrooms from additional insulation.
3.6. Consistency and certainty of compliance and consenting
Clear and up-to-date requirements in acceptable solutions and verification methods support consistency of how the requirements are applied and help provide certainty.
3.7. Topic 15: The modelling method includes requirements that are unclear or outdated
Areas in the modelling method where current requirements and assumptions are unclear or unnecessary.
3.8. Topic 16: The schedule method does not adequately limit heat losses and gains from skylights in large buildings
Proposed amendments to Acceptable Solution H1/AS2 Energy Efficiency for buildings greater than 300m2 to limit the permitted area of skylights in the schedule method to 1.5% of the roof area.
3.9. Topic 17: Thermal bridging from framing in walls is not adequately considered
Proposed changes to the values for construction of framed walls.
3.10. Topic 18: How the areas of roofs, walls and floors should be measured is unclear
Proposed change for roofs, walls and floors to be measured using overall internal dimensions.
3.11. Topic 19: NZS 4214 includes ambiguous instructions for determining the R-values of roofs, walls and some floors
Proposed change to provide clear requirements on how to apply NZS 4214.
3.12. Topic 20: For some mixed-use buildings it is unclear whether H1/AS1 and H1/VM1 can be used, or H1/AS2 and H1/VM2
Proposed change to provide clearer requirements for establishing which of the H1 acceptable solutions and verification methods apply for mixed-use buildings.
3.13. Topic 21: The look-up tables with R-values for slab-on-ground floors do not cater for some common situations
Proposed changes to Acceptable Solution H1/AS2 that enable the use of the look-up tables for slab-on-ground floor R-values for more situations.
3.14. Topic 22: Acceptable Solution H1/AS2 and Verification Method H1/VM2 include obsolete provisions and definitions, and outdated references to documents and tools
Proposed changes to Acceptable Solution H1/AS2 and Verification Method H1/VM2 to make them user-friendly and reduce the risk of misinterpretations.
3.15. Summary of the proposals for large buildings
Summary of proposals to change Acceptable Solution H1/AS2 and Verification Method H1/VM2.
3.16. Transition period for large buildings H1/AS2 and H1/VM2
Proposed period that the existing Acceptable Solutions and Verification Method will remain in force.
3.17. Transition period for large buildings H1/AS2 & H1/VM2
Question on the transition time of 12 months for the proposed H1/AS2 and H1/VM2 changes to take effect.