Passive house - Castletown

There has been a test of how super well insulated homes perform for new public sector homes.  Two examples of these “Passive Homes” were built in the new 3-bed semi-detached homes at Janet’s Corner in Castletown.

The principles behind a passive house are that the property is built to very high standards of construction, incorporating high levels of thermal insulation built into the walls, complemented with triple glazed windows and doors, and a high level of air tightness, or a very low level of air leakage, to combat heat loss. As the building envelope is so airtight, a mechanical ventilation system with heat recovery is installed in the properties, this system draws in fresh air from outside and via a plate heat exchanger recoups the heat from the extract air drawn from the kitchen, bathroom, and toilet, the fresh heated air is then supplied into each of the three bedrooms. This ventilation system runs 24 hours a day, so to combat any build-up of moisture and thus prevent condensation inside the property.

The hot water provision for the property is supplied by a gas fired instantaneous hot water generator, and the heating requirements are supplied by the casual heat gains caused by living in the property like cooking, bathing, electrical appliance usage, tv’s, computers etc. The building is orientated to maximise the benefit of solar gains in the winter but also with shading to protect the property from solar gains in the height of summer.

They were built using local skills, and importantly look like conventional homes, but with subtle differences like larger windows on the south side of the house than the north side, and better insulation standards everywhere.  Future houses could reduce energy used for hot water even more by having a small solar hot water panel on the roof.

Results from this project proved that they used less than half the energy of “standard” houses, even allowing for the electricity needed for TV’s, lights and the ventilation system, and was a very warm home all year round, despite not having a central heating system – insulation works!