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.
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.