Passive House Roof Insulation

Typical conventional insulation materials mineral wool polystyrene cellulose require layers of about 30 cm.

Passive house roof insulation.

An external wall a floor to the basement or a slab on ground a ceiling or a roof is characterised by the thermal heat loss coefficient or u value. Inadequate insulation and air leakage are the main causes of heat loss in homes. The irish standard part l 2011 for a traditional roof structure is 0 16 w m 2 k. Draught sealing is also important as draughts can account for up to 25 of heat loss from a home in winter see passive solar heating.

Even a straw bale wall of 50 cm or more would be suitable for the passive house. If you re familiar with any passive house projects you may be thinking about double stud walls that are a foot thick or regular walls with 6 to 12 inches of rigid insulation on the outside. It grew out of the superinsulation movement after all. It s important to maximise passive solar gain meaning the sun is used as often as possible to heat the air and water the home consumes on a daily basis.

These key principles are high levels of thermal insulation passive house windows heat recovery ventilation airtightness and thermal bridging free design. For example if insulation is installed but the house is not properly shaded built up heat can be kept in by the insulation creating an oven effect. State of the art vacuum insulation materials allow for very slender yet highly insulated. More information on how insulation works determining insulation requirements options for roof insulation options for wall insulation options for floor.

3 200mm kingspan insulated. This is very close to the passivhaus standard 0 10 0 15 w m 2 k however it still does. Passive houses are working examples of dwellings with very good thermal insulation standards. That super insulation like it is used passive houses does not pay back.

2 xtratherm detail showing upstand of insulation around the edge of the floor slab to minimise thermal bridging with the inner leaf of the cavity wall. Thermal insulation for passive houses must be extremely effective and so thick walls are built up using super insulation to achieve high r values. Insulation acts as a barrier to heat flow reducing heat loss in winter to keep the house warm or reducing heat gain in summer to keep the house cool. To achieve the passivhaus standard passive roofs need high levels of insulation thermal bridges need to be eliminated and the structure itself needs to be airtight.

The thickness can even be reduced to 20 cm with common polyurethane foam insulation materials.