We have been talking with Roxul makers of the arguably the best batt insulation available. They are interested in being part of our project and of suggested that their newer product called Comfort Board would be a better way to reach our goals of R44. This product would be installed exterior to the building sheathing, on the outside of the framing. Exterior insulation like this makes for a continuous building envelope that is more efficient. With any luck Roxul will be able to support our project in a big way.
At long last we have come to a decision about insulating our slab. We installed 6” of EPS foam under the slab of the house with 3” of insulation between the slab and foundation walls. In the garage we put only 3” under and 1 1/2” insulation around the perimeter. Our crawl space will have 3” of rigid board installed on the walls with plywood over top to assist in mounting plumbing pipes and pumps.
With this system we are leaving all of the concrete exposed to the cold, choosing instead to bring the insulated layer around to the inside of the concrete. Our 12” thick wall will cover the 8” concrete wall and 3” of foam before the slab starts.
We have broken ground on the 8th Living Building Challenge project in BC. The ground was easy and sandy. Ground water was found about 8’ below the surface. This was expected due to the spring rains and high water tables of the nearby creek. Our rain water tanks and earth tubes will be kept 1’ above ground water. Our foundation and footings are well above this level (2’ required by local code).
Integral Design Group used their expertise and experience in the designing of this unique system. The HVAC is designed to take fresh air and return air through a number of 4” diameter pipes called earth tubes. In the process the air takes on the temperature of the ground. According to studies the earth tubes an have change the temperature by up to 13 degree Celsius. In the building world there is lots of discussion about this use of this passive technology. The long and short if it is, it works.
“We love the earth tube system installed in our home” Chris and Cathy Jennens, Kelowna, BC
In this house we will be running all of the air supply to the house fan through these tubes. Manually adjusted dampers will mix the approbate amounts of fresh air into the system. These dampers will be adjusted in the spring and fall.
Many materials for the earth tubes were considered. (More detailed discussion can be found here ) Concrete, steel, HDPE, PVC, and polyethylene, . Concrete works well for larger projects but is expensive and laborious to install without the use of heavy machinery. Steel when coated offered an attractive alternative, however it’s proximity to water table and cost of install put questions in our mind about longevity and ruled it out of this project. HDPE is available in many sizes including the 18” diameter we required, but the costs of the piping and heat welding required to connect the joints was expensive. PVC is toxic and not permitted on LBC projects. That left us with polyethylene or “big O” as it’s referred to. This piping is inexpensive, flexible, but only comes in 4” diameters. Our challenge now is to bury the 18 4” pipes, each 100’ long, into the space beside the Ethel Lane House.
Integral Design Group has been excellent in helping with the design of Ethel Lane House. Their scope of work includes:
Here is a wonderful explanation of the systems of Ethel Lane House prepared by Integral Group.
Fantastic event. Thank you to everyone that took the time to join us. Thanks to Jordan Lige’s family for making this possible.
The goal of the night was to share with the community an overview of the project and introduce the family to the community. We opened the event by presented a brief overview of the project and how it relates to the Living Building Challenge. Then we heard from Jamie and Trevor of Integral Design Group about the thought behind the mechanical systems. Lastly the owners Joanna and Nathan shared a few thoughts about the process and their hopes for the project.
The evening was also attended by:
The Joanna and Nathan Lige family, Integral Design group, En Circle Design Build, UBCO Eco Art video documentary team, Allen & Mauer Architects, Hugh Bitz Architect, Stonebridge Contemporary Originals, Tatham Design Associates, Waterplay, Bench Landscape Architecture, and many other brilliant minds.
We look forward to our onsite workshop coming up in August/Sept.
With the help of Trevor Butler and his company Earth Tubes we will be installing buried earth tubes in Ethel Lane House similar to the ones in the picture. Over the centuries this “technology” has been used around the world but only recently have designers and engineers begun to revisit these systems.
Our goal is to install the equivalent of 12” diameter duct into a trench around the perimeter of the building. This trench will simply act as a method of cooling the fresh air supply in the summer or warming it up in the winter. We will be using 100” of polyethylene Big “O” similar to the material used in perimeter drains.
As noted in our last post we have had to do away with a full house craw space. Instead we have opted for a hybrid of sorts. We will digging a dropped crawlspace under the the bathroom to accommodate the composting toilet. This space will hold the systems for the Black, Grey and fresh water supply. All pumps and systems that can be damaged by water must be installed above the high water mark, which is only a couple of feet down from the ceiling. Our composting toilet has no electrical or mechanical systems that will be damaged by water, and our backup sump pump is submersible.
We have also moved the rain water tanks out of the crawlspace to a hole to be dug under the deck. This will eliminate the chance of hydraulic lifting that might happen in flood situations. Our choice of tanks has also changed and we will be installing only one Super Tank from Premier plastics that will be buried below grade close to spring ground water levels, which are rumoured to be 8’ below ground in that area.
Our surveyor, Goddard Land Survey, has completed their work to locate the building at the back of the property. And now we are left to consider the elevation of the building to the nearby Mill Creek.
The two numbers that are important are:
1. Lake level 343.6m
2. the floodplain level of Mill Creek is 347.4m.
Our survey indicated that our elevation at ground will be 347.91m.
Lots of discussion this week around Water Storage systems. We explored a number of options for storage but ultimately ended up deciding on installing Polyethylene tanks into basement.
Options considered were Made in BC, and NSF Food Grade
Pro: Good volume per sqf of floor, Moderately Priced, Easy to clean,
Con: Must be tethered to foundation so it doesn’t lift building (in flood)
Concrete tanks (built in place)
Pro: Highest volume per sqf, best integration into building
Con: Expensive, difficult to build proper lid, would require proper engineering, waterproof concrete additives expensive, High water table added a lot of engineering, material and labour costs,
Concrete Tanks (pre-formed)
Pro: Simple to install
Pro: Inexpensive, Flexible, no need for tethering (due to high water table), inexpensive shipping
Con: harder to clean, Least volume per sqf