New Zealand Building Code, H1 Clauses Breakdown
January 12, 2024 By Anthony Broatch
General building code details
In New Zealand there is a Building Code that contains rules and standards for constructing a house or commercial building. The building code is broken down into clauses covering each area of construction compliance.
One of these clauses is H1 Compliance which makes sure that buildings are designed and built so that they operate in an energy efficient way. There are 3 main compliance method pathways for H1 as follows and each method as 2 sub pathways depending on the building type:
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H1 Modelling Method: This method assesses both heating and cooling energy performance of your building design through computer simulation models. By considering factors such as insulation, building constructions, solar shading, and solar performance of glazing, this method provides the most flexibility and often the best construction cost savings.
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Calculation Method: This method considers only heating energy performance of your building design and provides some flexibility in thermal performance of building constructions.
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Schedule Method: This method considers only heating energy performance of your building design and all windows, walls, roof, floors, and doors must meet or exceed the minimum thermal performance requirements set out in clause H1.
The two sub pathways of each option above is
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Small commercial buildings or residential
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Large commercial buildings
Breakdown of Each H1 clause
H1/AS1: Energy efficiency for all housing and buildings up to 300 m2
General
This standard covers the schedule and calculation method for the following building types:
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All residential or community care projects
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Any commercial or residential building up to 300 m2
The schedule method details
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Each building component (wall, roof, floor, glazing) must meet the minimum required thermal resistance (R value) for the region in the country.
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You are limited to a glazing areas of 30%
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considers space heating energy use only
The calculation method details
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You have flexibility in the thermal resistance (R value) of each building component however the overall heating energy use must be the same as a building with the minimum required thermal resistance (R value) for the region in the country.
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Although there is flexibility in the thermal resistance (R value) of each building component, the R value) of each building component must not be less than half the minimum required insulation R value (thermal resistance) level stated for the schedule method.
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You are limited to a glazing area of 40%
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considers space heating energy use only
H1/AS2: Energy efficiency for buildings greater than 300 m2
General
This standard covers the schedule and calculation method for the following building types:
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Any commercial building over 300 m2
The schedule method details
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Each building component (wall, roof, floor, glazing) must meet the minimum required thermal resistance (R value) for the region in the country.
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You are limited to a glazing areas of 50%
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considers space heating energy use only
The calculation method details
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You have flexibility in the thermal resistance (R value) of the wall, door, and window building component however the overall heating energy use must be the same as a building with the minimum required thermal resistance (R value) for the region in the country.
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No flexibility is allowed in the roof or floor R values and they must meet the minimum required thermal resistance (R value) for the region in the country.
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There is no limitation on glazing area.
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considers space heating energy use only
H1/VM1: Energy efficiency for all housing, and buildings up to 300 m2
General
This standard covers the schedule and calculation method for the following building types:
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All residential or community care projects
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Any commercial or residential building up to 300 m2
The modelling method details
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There is no limitation on glazing area.
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There is no limitation on minimum required insulation R values.
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You have flexibility in the thermal resistance (R value) of each building component however the overall heating and cooling energy use must be the same as a building with the minimum required thermal resistance (R value) for the region in the country and no solar shading.
H1/VM2: Energy efficiency for buildings greater than 300 m2
General
This standard covers the schedule and calculation method for the following building types:
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Any commercial building over 300 m2
The modelling method details
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There is no limitation on glazing area.
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There is no limitation on minimum required insulation R values.
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You have flexibility in the thermal resistance (R value) of each building component however the overall heating and cooling energy use must be the same as a building with the minimum required thermal resistance (R value) for the region in the country and no solar shading.
H1/VM3: Energy efficiency of HVAC systems in commercial buildings
General
This standard covers the energy efficiency and insulation requirements HVAC systems in commercial buildings
Reshape Consulting can guide you through the intracies of each of the H1 building code clauses and help you achieve compliance without comprimising on energy efficiency or aesthetics.
References
New Zealand Building Code Clause H1
https://www.building.govt.nz/building-code-compliance/h-energy-efficiency/h1-energy-efficiency/
About the author
Anthony Broatch
Director, H1 Specialist, Chartered Senior Mechanical & Hydraulic Engineer
BE(Mech), CEng, MCIBSE, MEngNZ
Reshape Consulting Ltd
I have had been involved in a energy efficency and energy modelling in buildings for the the last 15 years and have worked on countless H1 complaince reports, building performance analysis projects, and energy audits.
