Passive House Roof Assembly

The irish standard part l 2011 for a traditional roof structure is 0 16 w m 2 k.

Passive house roof assembly.

The roof trusses alone cost 20 000. 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. 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.

Passive house has a reputation for requiring ungodly amounts of insulation. 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 building science details for this roof system involve a method that is increasingly common for cathedral roofs in passive house construction.

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 wall assembly design. The striking building is situated on nearly three acres of rural land bordered by woods and farm fields in freeland michigan. 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.

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. 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. The super insulated air tight building enclosure includes masonry walls with dense pack cellulose and continuous exterior mineral wool and polyiso insulation that provides r 34 a roof assembly of r 61 that combines dense packed cellulose in the rafter cavity and continuous mineral wool and poly isocyanurate rigid insulation outbound of the roof sheathing r 36 under the basement concrete slab and building details to mitigate all thermal bridging. 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 carpenter reported that he could have got her the stock plan and all the upgrades to passive house for less than the cost of her roof.