Passive House Roof Insulation

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.

Passive house roof insulation.

These key principles are high levels of thermal insulation passive house windows heat recovery ventilation airtightness and thermal bridging free design. State of the art vacuum insulation materials allow for very slender yet highly insulated. Insulation and ventilation are both important components in the design and build of a passive house but there s still much more to it. 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.

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. 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. 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. 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.

Passive house has a reputation for requiring ungodly amounts of insulation. 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. Even a straw bale wall of 50 cm or more would be suitable for the passive house. That super insulation like it is used passive houses does not pay back.

This is very close to the passivhaus standard 0 10 0 15 w m 2 k however it still does. Typical conventional insulation materials mineral wool polystyrene cellulose require layers of about 30 cm. 1 foundation detail at denby dale the uk s first certified cavity wall passive house with a lightweight insulating concrete block at the wall to floor junction. Inadequate insulation and air leakage are the main causes of heat loss in homes.

Thermal insulation for passive houses must be extremely effective and so thick walls are built up using super insulation to achieve high r values. It grew out of the superinsulation movement after all. Passive houses are working examples of dwellings with very good thermal insulation standards. The irish standard part l 2011 for a traditional roof structure is 0 16 w m 2 k.

3 200mm kingspan insulated.