Showing posts with label Polystyrene foam insulation. Show all posts
Showing posts with label Polystyrene foam insulation. Show all posts

Monday, June 21, 2010

Energy saving features of the house

Here is what builder John Nelson had to say about some of the things we are doing to save energy in building the Sunnyland Sunhouse;

'The method involves removing most of the plywood sheathing and covering the entire exterior of the building with rigid foam with a rating of R-5. In the stud bays I will use R-23 blown in blanket insulation. The use of an uninterrupted R-5 layer on the exterior that is also air-sealed with glue and tape (and has a perm rating similar to Tyvek) has the effect of keeping the interior of the wall warm and dry almost every day of the year. By putting the vapor barrier on the outside and eliminating the vapor barrier on the inside, this method actually reduces the chance of having condensation occur inside the wall cavity and still allows any moisture to get out after those few days of the year when temperature and dew point create the possibility of moisture condensing. By combining these R-values, installing in this manner and using a rain path gap between the foam and the siding, I hope to show with testing that the wall is functioning at R-30. Combine that with R-38 in the floor, raised heal trusses and R-60 in the attic, foam spayed to seal the rim joist areas beneath each floor, and advanced framing techniques to limit thermal bridging, I am attempting to create what I call an Extreme Insulation Envelope that should make it possible to heat or cool the house with almost no energy.

Some other interesting features that the future owners of this home will hopefully appreciate include:

Efficient plumbing design with high-efficiency hot water tank, waste-water heat recovery, and super-short hot water plumbing lines
Solar panels (more about that later!)
Mini-split heat-source with a SEER rating of 25
High indoor air quality
A vegetable garden, with ripe vegetables at the time of sale (around August 1)
Thanks to all who have gone before me and provided me with the opportunity to produce a house like this that can sell for less than 20% above the median price in Whatcom County. My belief that green buildings can be built without much added cost is being demonstrated here. Methods used to realize this project will be shown to the public via internet and other means, should anyone be interested. A website will be online by June 21. Sustainable Connections has suggested that they will showcase the home and the RE Store has published some information about their efforts to reclaim materials from the demolished house and to help me keep the building out of the landfill. By the way, zero percent of the old house became trash.'

Friday, June 18, 2010

Exterior foam insulation now in place










We are making a lot of progress on the Sunnyland Sunhouse & I'm so busy with things that I haven't had a chance to post anything for a while. Here are some pictures of where we are right now.
The exterior is wrapped in 1 inch of polystyrene foam with an R-5 value.

The roof is on and windows are in. Doesn't look too pretty yet but it looks a lot more like a house!




Here is a detail that shows a lot; Studs at 24"oc with the window sized to fit between so that minimal lumber is used. Metal hangers replace cripple studs.


Foam spray in joist bays above seal the space from air leaks. Exterior 1" foam has replaced OSB sheathing where it is not needed for structural reasons. The window header uses 2x material with polystyrene sandwiched between for more insulation value.

At right are some of the decorative knee braces
that will be used on the house. They are built of scrap and recycled lumber. The red-toned pieces are made from fence posts found on the site. They are excellent quality cedar.