We are working on our first certified Passive House Project that will be built for the Fischer family in Canberra.
Located 608 metres above sea level, this is an excellent test of how our Habitech System will perform in a cool temperate climate zone. The particular challenges of this climate are large daily temperature shifts, high solar gain and low humidity. Clear skies give rise to cold winter nights followed by excessive sunshine during daylight hours that can cause overheating.
We have been working with Harley Truong of H3 Space as an independent Passive House Consultant and yesterday we discussed the preliminary rating results. The standard Habitech panels and construction details are complemented by a mechanical ventilation heat recovery system as well as high quality glazing from Logikhaus.
Using the Passive House Planning Program, the design is projected to achieve a heating demand of 15.9kWh/m2 per annum. As a first pass, the proposed design is only 0.9kWh/m2 per annum too high from complying with the passive house standard of 15kWh/m2 per annum. This is assuming a worst case air-tightness test result of 0.6 air changes per hour, when our system can achieve better performance in practice.
The small residual heating and cooling loads will be met by all-electric systems powered by on-site solar photovoltaic generation. If this energy were to be purchased at typical grid electricity prices it would involve bills in the order of $710 per annum. Although Nathers energy ratings and Passive House methods are calculated differently, to put the result in context, this minimal level of energy use would be expected of a 9 star house.
We are now working on some minor adjustments to ensure the completed house will comfortably meet the passive house standard. It is really exciting to see our commitment to creating super-insulated airtight homes vindicated by this independent analysis that is backed by proven building science.
We will keep you updated as this project and others progress.
Niall O Healaithe, Senior Designer Habitech Systems