The South facing sunshades on the Langley Passive House are permanent, sized to reject the overheating summer sun while allowing passage of the winter sun through the windows to heat the home, and fit the architectural style of the home. There are two levels of sunshade one at the roof level as an extension of the eaves and the other shades the main level windows and doors as a continuous wall mounted canopy.
The upper eaves are extensions of the top chord of the roof trusses and form an angled soffit with continuous venting. This overhang shades the upper level windows from the steep angle of the summer sun. The lower angle winter sun is not obsured by the length of the overhang allowing the warming rays to play a key role in heating the interior of the home.
The main level canopy is shown in the detailed close-up image and is attached such that it does not penetrate the insulation and create a thermal bridge. The trusses are hung off 2×4 ledgers which are in turn attached to the 2×4 vertical strapping without penetrating the insulation.
Doors are installed similarly to windows. A 2×4 ripped is offset at jamb and head. The door frame rests on plywood spacers and is glued/sealed with adhesive foam. The frame is over a self-adhered flashing at sill which itself sits above rigid EPS at concrete foundation.
As mentioned in part 1 of the series this wall detail takes a high vapour permeance or breathable approach in contrast with a more vapour closed system such as traditional 6 mil poly, spray foam insulation, or SIPS panel.
The South facing sunshades on the Langley Passive House are permanent, sized to reject the overheating summer sun while allowing passage of the winter sun through the windows to heat the home, and fit the architectural style of the home.
The Langley Passive house is a ‘split-insulated’ wall assembley pioneered by RDH Building Engineering for the BC climate. This strategy is described in the Building Enclosure Design Guide (HPO 2011) and Guide for Designing Energy Efficiency Building Enclosures (FPInnovations 2013) both by RDH.
