Changing H1 standards in NZ
Changing H1 standards in New Zealand and getting windows above requirement
It has long been held that New Zealand homes are lacking when it comes to warmth and moisture prevention. Our windows, in particular, act like ‘open pits’, allowing warm air to pour through to the outside. But why should this be?
The problem with NZ windows
Because of our building materials’ low tolerance for moisture in New Zealand, we tend to build windows with sizable cavities for drainage. This style means that the frame isn’t particularly air-tight, so a lot of heat is lost through the spaces between the wall and window. On top of that, windows are primarily made with aluminium frames. Aluminium is one of the most heat conductive materials; hence lots of heat loss via frames and visible condensation on the frames even with double glazing. Even with warm uPVC windows or thermally broken aluminium ones, typical installation outside of the insulating layer of the wall creates thermal bridging where heat is lost bypassing the warm window frame.
Solving this problem is simple. Use only uPVC or well-insulated aluminium frames for your windows. Use warm spacers in the glass units. Install Koffman triple glazing for only 10% extra cost and use a well-proven recessed installation method.
What the H1 standard means
The H1 standard in New Zealand is about changing homes to be more energy-efficient and healthier, mitigating the risk of cold, damp conditions that have historically led to health problems. Part of this change has involved recognising New Zealand’s unique ‘micro-climates’ across the North and South Island, divided into six different zones.
Each zone has an acceptable level of thermal resistance for windows, a mandatory requirement for builders that was updated at the end of November last year. This update requires that the glass’s thermal resistance meet the new installation standards.
What is the R-value?
The R-value, or resistance value, measures the amount of thermal resistance an object (such as a window) has. In other words, it measures the transfer from heat to cold in a set number of units.
As you’ll see from the below New Zealand climate zone map, the further down the country you go, the higher R-value is needed. This is generally due to the further position from the equator and the lack of humidity that traps air (but that also increases unhealthy condensation). However, the inland regions of the North Island also experience a wide range of temperature extremes, getting as cold as parts of the West Coast, which is why it’s in a region 4 zone.
Zone 1
Districts: Far North, Whangarei, Kaipara, Thames-Coromandel, Western Bay of Plenty, Tauranga City, Whakatane, Kawerau, Opotiki
Required R-value: 0.37
Zone 2
Districts: Hauraki, Waikato, Matamata-Piako, Hamilton City, Waipa, Otorohanga, South Waikato, Waitomo, Gisborne, Wairoa, Hastings, Napier, Central Hawke’s Bat, New Plymouth, Stratford, South Taranaki, Whanganui
Required R-value: 0.46
Zone 3
Districts: Rangitikei, Manawatu, Palmerston North, Horowhenua, Kapiti, Porirua, Lower Hutt, Wellington City, Tasman, Nelson City, Marlborough, Kaikoura, Chatham
Required R-value: 0.46
Zone 4
Districts: Taupo, Rotorua, Ruapehu, Rangitikei, Tararua, Upper Hutt City, Masterton, Carterton, South Wairarapa, Buller, Grey, Westland
Required R-value: 0.46
Zone 5
Districts: Hurunui, Waimakariri, Christchurch City, Selwyn, Ashburton, Timaru, Waimate, Waitaki, Dunedin City
Required R-value: 0.50
Zone 6
Districts: Mackenzie, Waitaki, Central Otago, Queenstown, Southland, Gore, Invercargill
Required R-value: 0.50
So what do I have to do?
As this is part of the requirements for new builds, you won’t need to do anything unless you’re in the building industry. However, if you are looking at building a new home or renovating your existing home, it’s a good idea to be aware of these requirements moving forward. While not officially standardised until November, proper roof and window insulation will prevent you from needing to renovate your house later on if you decide to sell or undergo development.
How Koffman can help
New Zealand’s standard of warmth and insulation is still relatively low compared to the European countries we model our window designs off. Our maximum standards here would equate to the bare minimum over most of Europe — which is why we believe in getting you something a little better.
Our uPVC double and triple seal windows have an R-value up to 2.7 times higher than the proposed New Zealand H1 standard for cold zone 5 and 6. They’re highly efficient at insulating against sound, with a reduction rate of up to 47dB (decibels).
We also offer high-standard aluminium windows, depending on the look you’re going for and the surrounding material used in your build. Our aluminium frames improve upon traditional frame models by including plastic and foam insulation within the frame. The long-lasting thermal insulation means both high and low temperatures can be tempered throughout the year.
Once you’ve consulted with your architect or designer over the proper windows needed and the sizing, the next stage is to ensure with them that your windows and doors are properly fitted. We can talk you through the installation process, what to expect and who to contact, whether you’re at the initial design stage or are looking to fit windows to your developing build project.
Contact us for a free quote, visit our showroom, or discuss your build project further.
Sites sourced:
- ArchiPro Editorial Team. “Rethinking our windows—the case for using uPVC in New Zealand” on ArchiPro. Date Published: 21st July, 2021. Site Link: https://bit.ly/3OQnghl.
- “Building work repairs and replacements – H1 compliance” on Building Performance.
- “Changes to H1 Energy Efficiency— What this means for you” on WindowMakers. Date Published: 2nd June, 2022. Site Link: https://bit.ly/3AAgmbJ.
- “Consultation document: Building Code update 2021” in Builder Performance. Date Published: 6th April, 2021. Site Link: https://bit.ly/3uwlx8y.
- Duder, Matthew. “Updated Energy Efficiency Requirements for New Builds” on EBOSS. Date Published: 29th November, 2021. Site Link: https://bit.ly/3bXTFDM.
- “Map C North” on Niwa. Date Accessed: 8th July, 2022. Site Link: https://bit.ly/3IqjQiY.
- “Understanding the new H1/AS1 Insulation Regulations” on POD. Date Published: 2nd May, 2022. Site Link: https://bit.ly/3Rn6NTw.
- “Understanding the R-value” on Bayview Windows. Date Last Updated: 23rd September, 2020. Site Link: https://bit.ly/3nNa5S9.
