Passive House Roof Assembly

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 assembly.

The striking building is situated on nearly three acres of rural land bordered by woods and farm fields in freeland michigan. It grew out of the superinsulation movement after all. The underside of the rafters will receive a smart vapor barrier fabric pro clima intello designed to resist the passage of moisture into the insulated cavities from interior space but still allow the cavities to dry to the inside if necessary. In terms of heating oil passive house buildings use less than 1 5 litres per square meter of living space per year far less than typical low energy buildings.

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. Both houses being built by john hodges have the following double stud larsen truss wall assembly optimized for passive house based on a value of r3 5 per inch for cellulose. Passive house prefab homes because the wall and roof assemblies can be built indoors while your site is being prepared and your foundation is being built because the walls and roof already have the insulation drywall and air sealing and need only on site assembly and windows you save an immense amount of construction time. The roof trusses alone cost 20 000.

And the construction of the roof sheathing and shingling were all more expensive than that of the stock plan house. 2x6 stick frame wall with dense packed cellulose in the cavities r19 plywood sheathing taped to act as vapor barrier and air barrier. The a haus was assembled with pre insulated wall and roof panels this single family home nicknamed the a haus is the first house in michigan to be certified by the passive house institute u s. Passive house buildings allow for heating and cooling related energy savings of up to 90 compared with typical building stock and over 75 compared with average new builds.

Passive house has a reputation for requiring ungodly amounts of insulation. The building science details for this roof system involve a method that is increasingly common for cathedral roofs in passive house construction. Passive house wall assembly design. Wall assembly for the kingston passive house note the almost continuous insulation layer it is interrupted only by the top bottom and cap plates required per the sip manufacturer s specification.

This is very close to the passivhaus standard 0 10 0 15 w m 2 k however it still does satisfy it.