2. Insulation in housing and small buildings

2.1. Background on energy efficiency for housing and small buildings

Background on energy efficiency for housing and small buildings.

2.2. Optimising insulation to better balance upfront building costs and longer-term benefits

Three key topics that cover ways insulation could be optimised to better balance upfront building costs and longer-term benefits.

2.3. Topic 1: The schedule method may lead to higher upfront costs and less cost-effective construction than the more flexible calculation and modelling methods

Discussion topic on whether the schedule method may lead to higher upfront costs and less cost-effective construction than the more flexible calculation and modelling methods.

2.4. Topic 2: The calculation method contains restrictions to the flexibility of roof, wall and floor R-values that can lead to unnecessarily costly and complex construction in some buildings

Discussion topic on whether the calculation method contains restrictions to the flexibility of roof, wall and floor R-values that can lead to unnecessarily costly and complex construction in some buildings.

2.5. Topic 3: Where underfloor heating is only used in bathrooms, the minimum R-values for heated floors may cause unreasonable upfront costs

Discussion topic on if underfloor heating is only used in bathrooms does the minimum R-values for heated floors cause unreasonable upfront costs.

2.6. Consistency and certainty of compliance and consenting

Discussion topics identified through sector feedback and BRANZ analysis.

2.7. Topic 4: The modelling method includes requirements that are unclear or outdated

Discussion topic on whether the modelling method used in the Building Code H1 Energy Efficiency requirements is unclear or outdated.

2.8. Topic 5: Thermal bridging from framing in walls is not adequately considered

Discussion topic on thermal bridging from framing in walls which is not adequately considered.

2.9. Topic 6: How the areas of roofs, walls and floors should be measured is unclear

Discussion topic on how the areas of roofs, walls and floors should be measured is unclear

2.10. Topic 7: NZS 4214 includes ambiguous instructions for determining the R-values of roofs, walls and some floors

NZS 4214 includes ambiguous instructions for determining the R-values of roofs, walls and some floors.

2.11. Topic 8: For some mixed-use buildings it is unclear whether H1/AS1 and H1/VM1 can be used, or H1/AS2 and H1/VM2

For some mixed-use buildings it is unclear whether H1/AS1 and H1/VM1 can be used, or H1/AS2 and H1/VM2.

2.12. Topic 9: The look-up tables with R-values for slab-on-ground floors do not cater for some common situations

The look-up tables with R-values for slab-on-ground floors do not cater for some common situations

2.13. Topic 10: The look-up table with R-values for vertical windows and doors in housing misses some common glazing types

The look-up table with R-values for vertical windows and doors in housing misses some common glazing types

2.14. Topic 11: Acceptable Solution H1/AS1 and Verification Method H1/VM1 include obsolete provisions and definitions, and outdated references to documents and tools

Acceptable Solution H1/AS1 and Verification Method H1/VM1 include obsolete provisions and definitions, and outdated references to documents and tools.

2.15. Summary of the proposals for housing and small buildings

2.16. Transition period for housing and small buildings

Proposed transitional arrangements for Acceptable Solution H1/AS1 and Verification Method H1/VM1.

2.17. Effects of the H1 insulation requirements on overheating and dampness risks in new housing

Effects of the H1 insulation requirements on overheating and dampness risks in new housing.