Eco house gets warm fuzzies

The people who end up living in Wanganui's experimental low energy house will be kept warmer than an unshorn sheep by 300mm of natural wool insulation in the ceiling.
Earlier this week the wool - washed waste from carpet manufacture - was blown into the ceiling cavity of the eHaus nearing completion at 5 Webster Pl in the Lithgow Dr subdivision on St John's Hill.
It's being built by partners Baden Brown and Jon Iliffe, of Eco Build Developments.
The layer of wool will have an insulation value of R5 - higher than the R2.9 required for the roof of a timber-framed building in Wanganui.
The wool would settle with time, Mr Iliffe said, and would breathe naturally, handling moisture and temperature changes. It cost more, but worked better and lasted longer than standard insulation made of recycled glass.
"For us, it just feels great to use wool, because it's a New Zealand product and it's not highly processed."
The house gets furniture and drapes in the next few days and the partners plan to launch it next Friday. They will open it to the public after that.
It will be for sale, for $590,000.
Mr Iliffe said building was only two weeks behind schedule, and landscaping had slightly exceeded the budget.
The materials used and building process used a lot of energy. But this would be more than offset by the small amount of energy needed to run the house for the next 50 to 100 years, Mr Iliffe said.
Economy of energy; The Chronicle got a preliminary tour of energy saving features.
The main one is that it is so well sealed. A recent pressure test moved less than 0.3 per cent of the air in the house in an hour. In an average new house all the air would have been replaced five to 10 times.
A 44-watt ventilation system works constantly, cycling air after removing the heat from it. It shares cupboard space with a hot water cylinder.
Hot water is provided by a solar system on the house roof. Mr Iliffe said it was expensive to put in but had a payback time of three-to-six years because it reduced electricity costs.
Heating will seldom be needed. It is provided by an Italian pellet fire that has a thermostat and is remote controlled.
Natural light comes through two skylights. They are double glazed, to prevent heat escaping through them, and will save on electric lighting.