by Laird Herbert
Leaf House has a new home in the Yukon, Whitehorse, Canada, and is back in the thick of tiny house construction. Plans for version.2 are complete and for sale on the website www.tinyhousing.ca, and Leaf House will be building one more custom tiny house this winter.
The company is testing a variety of innovative materials and technologies suitable for tiny house construction in cold climates. Leaf House is using this upcoming tiny house as a case study, incorporating extremely energy efficient windows, an innovative compact Heat Recovery Ventilator (HRV) for small spaces, a lightweight concrete finish for countertops, metal mesh rainscreen, aerogel insulating material, and lightweight panels and interior finishes.
The most exciting technology showcased in the tiny house, which is the subject of this post, is the vacuum insulated panel (VIP). VIPs are an insulating product that is not yet available in commercial construction but have incredible potential for tiny houses and the recreational vehicle industry. VIPs are thin (1/2” to 1”) yet have an R value of R30 per ½”. The extremely low pressure in the panels prevents heat transfer, and overlapping the panels means that a wall of R60 can be achieved with only 1” thick of material. The panels are filled with silica and are also lightweight. The space and weight savings mean that tiny house construction might just be the perfect application for VIPs.
An R30 VIP panel
With VIPs tiny house builders can use 2X3s, 2x2s or metal tubing for framing, reducing the overall wall size significantly, yet achieving R60 efficiency with little weight. Leaf House will be building three different kinds of walls to test different wall designs. The first is studs on 24” O.C. with the VIPs and a layer of spray foam between the studs which also acts as a vapour barrier. The second is a double stud wall with a double layer of VIPs for R60 on the north side, and the third is a curtain wall that will also be R60 and hang over the structural framing.
The biggest challenge posed by VIPs is that they cannot be cut, bent or modified in any way. This means that the tiny house must be designed to the dimensions of the panels, including the rough openings and around the wheel wells of the trailer. Any punctures to the panels will break the seal and they will no longer function to such a high efficiency, which means construction can be a little nerve wracking when using a nail gun. Leaf House is countering this limitation by wrapping the entire structure in R-8 foam and then spray foaming any gaps in the VIP panels, creating a vapour barrier in the process.
Conceptual rendering of Case Study Tiny Home
VIPs just may be the ultimate material for tiny house construction or RV manufacturers. They allow an R60 wall to be built in an incredibly compact footprint, an option which has not really being available to tiny house builders to date. In the Yukon being able to build such an energy efficient tiny house wall is a huge advancement for cold climate construction and the technology will have important ramifications on construction in the north. Please keep posted to the website www.tinyhousing.ca for updated pictures of the tiny house and information on VIPs, as well as the other technologies showcased in the tiny house. Expect to see the completed home to be posted for sale by May 2013. Manufacturers can source the panels from Panasonic Canada.