Passive heating technology: Perhaps the most ingenious part of the passive house concept is its
ability to heat (or cool) the inside spaces with only a modest input of heat or cooling from exterior energy
sources. As fresh, cold air enters the house through the ventilation system, it is heated (or cooled) by the
warm air it passes on its way out. Some systems have the incoming air passing through subterranean heat
exchangers which extract significant heat from the ground. Various forms of direct, on-site collection of solar
enenergy may also be incorporated in the building design. Only small wattage electric heating needs to be
This paper from Germany gives some idea of the benefits. < CLICK
The prices of electricity, the chief source of heating energy in New Zealand, continue to rise. As at the end of 2011, it is proposed that the re-elected National Party government will sell off 49% of shares in the strategic resource of New Zealand's own hydro-electric dams and power-plants. It seems certain that the price of electricity will rise following these sales. Electricity prices are already highest in locations near the dams, which include some of the coldest-climate districts of New Zealand, and therefore those in most need of energy conservation.
In many of these places, it is no longer legal to install in a new house, as of right, a coal-fired or a log-fired fireplace. These are the sources of least expensive house heating. The residual options then become diesel-fired, gas, and wood-pellet fires, as well as electric so-called heat pumps, all of which require electricity to run.
The constancy of electricity supply in New Zealand, especially in the south, always has concerns about being broken. If not by drought ( giving shortage of water to drive the generator turbines ), then by wind or snow damage to the electricity supply lines. It is not many years ago that a snow storm inflicted severe damage to 1,200 km of transmission lines in the Ashburton district, and some consumers were without power for 6 weeks in the depths of a particularly cold winter. They had extreme discomfort inflicted on them, and lives of the elderly were put at risk. Many people installed small petrol- or diesel-powered generators to keep vital electrical equipment functioning.
Consequently, it is good sense when building a new house, to choose an authentic Passive House, because the technology required in its construction will ensure that all heat released inside the home will be conserved very well, and the amount ( and therefore the cost ) of supplied electricity will be the lowest reasonably possible because only a small amount of electricity will need to be purchased for house-warming (or cooling).
Note, that in a Passive House, the retained heat is distributed reasonably uniformly throughout the whole house, not as most other systems have it which is to heat only those rooms actually being occupied. This means that for once, bedrooms in winter can be a place of real comfort in New Zealand, instead of imitating freezer-chests. And, the whole house is supplied with a constant supply of filtered fresh air at a steady rate independent of whether or not a gale is blowing outside, and, in winter, without freezing the house in the process. Dust, smog, pollen, vehicle exhaust particulates and other allergens, insects, and rodents and the like, can not gain entry through the automatic and continuous ventilation system. Neither do windows have to be left open for the inadvertent benefit of burglars or possums. Similarly, in those houses where there is a cigarette smoker living, the cigarette smoke is sucked out fairly quickly.
Would you like to see a passive house in New Zealand now?
You can follow the blog of the first build at
New Zealand's first Passive house blog-spot
Another NZ passive-house is documented on-line, on facebook. If you are a facebook user, you should have no problems viewing these pages.
A New Zealand Passive house set of informative pages
A New Zealand Passive house - the base page
Congratulations to Brooke the Architect (MOAA Architects) for what looks like a thorough job, and likewise the builder for following instructions so well. Lots of construction detail in here.
Links to pages about the seven precepts of Passive House design.
Very efficient Insulation
No thermal bridges
Passive solar gain
Prices / costs