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New NZBC H1 Requirements

On the 29 November 2021 the MBIE released some new compliance paths for NZBC clause H1 Energy Efficiency. These new compliance paths are quite a step-up on previous requirements and are summarised as follows:


NZBC H1/AS1 - Residential and Commercial <300m2

  • Is in effect from 29 November 2021, but has a grace period until 2 November 2022 before mandatory enforcement.

  • No Longer cites NZS4218. R values are now directly in the acceptable solution.

  • Significant increase in insulation requirements summarised in the below table:


  • Will require much more roof insulation thickness, or moving toward PIR sandwich panel roofing systems.

  • Will require double glazing moving toward triple glazing, low E coatings and more thermally efficient window framing systems.

  • May require underslab insulation layer depending on building size, location and layout.

  • Will require much more insulation for suspended floors.

  • Solar gain comment on means to reduce this. Lack of tangible requirements.


NZBC H1/AS2 - Large Commercial >300m2


  • Is in effect from 29 November 2021, but has a grace period until 2 November 2022 before mandatory enforcement.

  • No Longer cites NZS4243 except for artificial lighting. R values are now directly in the acceptable solution.

  • Significant increase in insulation reqruiements summarised in the below table:


  • Will require much more roof insulation thickness, or moving toward PIR sandwich panel roofing systems.

  • Will require double glazing for all commercial buildings.

  • Will require more use of thermal breaks, particularly on steel framing.

  • May require underslab insulation layer depending on building size, location and layout.

  • Solar gain comment on means to reduce this. Lack of tangible requirements.


NZBC H1/VM1 - Residential and Commercial <300m2

  • Modelling method of AS1.

NZBC H1/VM2 - Large Commercial >300m2

  • Modelling method of AS2.

NZBC H1/VM3 - Energy efficiency of HVAC systems in commercial buildings

  • Is in effect from 29 November 2021.

  • Is a completely new requirement for HVAC in commercial buildings

  • Air conditioning system control, operating times and zoning, economy cycles, variable speed fans requirements.

  • Mechanical ventilation system control, operating times and zoning, limiting outdoor flow, variable speed fans requirements.

  • Fan efficiency and duct component max pressure drops requirements defined.

  • Ductwork insulation and Sealing requirements defined. Flexible ductwork to R1.0, Rigid ductwork in conditioned space R1.2, where exposed to sunlight R3.0.

  • Pumps to be a minimum efficiency and pipes sized for pressure drop requirements defined.

  • Pipework Insulation requirments; defined minimum R1.7 for refrigerant pipes <40mm. (parcoil 6.35mm copper 10mm insulation about R0.5)

  • Space heating to use approprialty selected equipment requirements defined.

  • Refrigerant chillers to comply with MEPS and given full load and part load efficiency requirements for air and water cooled requirements defined.

  • Unitary AC equipment over to comply with MEPS and given efficiency requirments for air and water cooled requirements defined.

  • Heat rejection equipment on condenser coils maximum 42W for each kW of rejected heat and cooling towers as per table requirements defined.

  • Facilites for energy monitoring, more requirements to collect time of use energy consumption data for larger buildings requirements defined.

  • Access to be provided for the commisioning, maintenance and replacement of equipment requirements defined.

https://www.building.govt.nz/building-code-compliance/h-energy-efficiency/h1-energy-efficiency/


Conclusions

  • Big changes in thermal envelope R values across all buildings and components. this will require a re-think on alot of the building elements design approach to improve performance.

  • Dissapointing there is not more focus on the solar gain of commercial buildings as a significant area to improve energy efficiency and building comfort.

  • Significant introduction of new requirements of HVAC systems design and performance.

  • Generally a good step in improving building efficiency.

Feel free to get in touch with one of our team to understand how these changes might affect your next project.


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