What is Passive House?
It is a building standard.
Passive house is considered the most rigorous voluntary, energy-based standard in the design and construction industry today, resulting in buildings that consume as much as 90 percent less heating and cooling energy than conventional buildings do.
Applicable to almost any building type or design, the Passive House high-performance building standard is internationally recognized, science-based and proven. The standard requires that the house can be maintained at approximately 200c all year round with extremely small amounts of energy. The standard also requires that the total energy use in the building is extremely low.
How is this standard achieved?
The standard is achieved by very careful design and rigorous calculations to accurately predict the performance of the building. Utilising solar gain through carefully placed windows, optimised insulation, ventilation and an airtight structure the total energy use for heating, cooling and all appliances used in the house is calculated. An internationally qualified designer will ensure that the building plans meet the standard using software developed by the international passive house association. This is then verified by an independent certifier. The design must account for the local climate, altitude, building orientation, shading, window quality size and positioning, ventilation system and insulation.
During and after construction testing will be carried out to ensure airtightness and the building will be supervised to ensure that all the passive house elements are correctly installed. When completed passive house certification is loaded on the iPHA website and a plaque can be paced on the house if wanted.
Passive house costs and building materials
Passive house is a standard relating to energy use and does not prescribe building materials. In order to achieve the very low energy use required to meet the standard certain building methods are required but the house may look like any other house and there is no prescribed materials or forms.
However there are building methods that work better than others for passive house certification and these preferred building methods include the most common building methods used in houses in New Zealand.
How much extra does a passive house cost?
The costs vary for each house. Compared to a house built to the minimum code requirements a passive house will have extra insulation, a high quality ventilation system and higher quality windows and appliances. In Europe where passive house is more established, certified passive houses can be built for the same cost as any other house due to well-established supply systems. In New Zealand the additional costs vary for each house and in one recent case a certified passive house has been built for less than a group home built house.
A certified passive house will not need much to be spent on heating or cooling and total power savings will offset any additional costs. There are many ways to reduce the cost of building and still maintain the high passive house standard, and it has been shown that a certified passive house can be built for the same price as a minimum code house in New Zealand.
Next Steps
If you are considering a low energy building, then contact us now. We’re happy to meet you or to discuss your plans over the phone, answer your questions and provide advice on a no obligation basis. We are not architects so if you wish to proceed with passive house certification then we will need to work with your house designer in the same way that a house designer and engineer work together on other aspects of any house design.
We have relationships with existing low-energy design architects who can do a full design if required. The important thing is to start early in order to ensure that the important decisions are made at the beginning in order to achieve the passive house standard. We look forward to hearing from you and discussing your plans, that is what we do.
