Come see the Yukon's Second LEED Registered Home

Come see our little SuperGreen laneway home - it's nearly finished!  This is arguably* the most energy efficent home in the Yukon, scoring an EnerGuide rating of 89!  The home is registred as a LEED Canada for Homes project and really is a model of sustainable housing in Whitehorse.

So come for a visit and tour - Friday April 3rd - drop by between noon and 7pm.  Note that this is a laneway house, so access it from the alley between Wood and Jarvis Street, between 7th and 8th.  



* Why do I say "arguably", well so there is one other home in Whitehorse recently rated at 89, but it is a big home and they used a big heat pump to score so well--the current EnerGuide rating system is not kind to small homes.  ALSO, Habitat for Humanity's triplex built out at Champagne & Aishikik First Nation's Takhini River subdivision scored a 90, but again they cheated by putting whopping 14kW photovoltaic array on the building.  It's building envelope isn't as energy efficient as ours, but the big renewable energy generation raises their overall EnerGuide rating.  Either way, these are all great, high performance homes and the debated about who's most efficient really is becoming a fun academic game. 

Heating people, not air

One of my favorite online publications is called "Low-Tech Magazine".  I few weeks ago I thought they'd written an article just for me--it was called: Restoring the Old Way of Warming:  Heating People, not Places

This article, along with the follow-up called How to Keep Warm in a Cool House, cause us to re-think how we currently heat houses.  The focus of these articles is challenging the current practice of heating air to keep people warm.  The authors look at alteratives in "spot heating" or heating the occupants directly. Any wood-burner knows the best place to be is sit around the wood stove in the living room.  More old-tech in action!

It was a particularly timely article because we just installed radiant electric heaters in the garage we are building.  The idea being to heat the occupants and objects instead of the air because when you open the garage door, out goes all the warm air.  They seem to work just fine, but will it translate into any significant energy savings? Tough to tell. 

Wall mounted electric radiant heaters in the garage.

The other interesting application the authors point out is that radiant heating (where you heat objects, not the air) is a good in existing, lower performance leaky houses.  By using radiant or conductive you can keep the house's air temperature lower, but the occupants can stay comfortable.  This will reduce energy losses through leakage of hot air from the house. There are some interesting ways of doing this both old-tech and new ideas (heated office chairs!)

Anyway, a good read if you interested in re-thinking how we stay warm and comfortable in your houses in a time of rising energy costs, especially existing older housing:

Part 1: Restoring the Old Way of Warming:  Heating People, not Places
Part 2: Radiant & Conductive Heating Systems
Part 3: How to Keep Warm in a Cool House

Lots and lots of Sprayfoam

Yesterday they started sprayfoaming our little laneway house.  Although sprayfoam is often used in certain applications as part of house construction, the unusual thing about this house is we are using a whopping 7.5" of closed-cell sprayfoam, installed on the outside of the building.  This acts as a big blanket that completely envelops the house.  Green Building Advisor calls sprayfoam the "King of Insulation".

First layer of closed-cell sprayfoam being installed.  All finished trim and windows have been masked-off to protect from over-spray.

Closed-cell foam has an R-value of 6 of 6.5 per inch.  This means the sprayfoam provides at least R45 on the outside of the house, plus it acts as our air barrier and vapour barriers.  

The closed-cell foam has to be built up in layers.  I looks like they can put on about 2" to 3" of foam each pass, so it will take them a few days to completely fill the 8" cavity.

Today while I was watching the contractor work (the job is so big the they actually using TWO sprayfoam rigs at the same time to do the job), I was thinking it seems a bit crazy to put on this much insulation because it is a lot of work (and cost).  But then I realized it is like pre-buying all of my fuel / energy now.  By superinsulating the house, I've built in keeping the house warm now, at the outset.  I won't have to buy a bunch of energy for the remainder of the life of the building because all of the insulation reduces the heating needs of this home by 90% over a conventional home.

The sprayfoam contractor is Energy North Construction and so far they seem to be doing a good job.  They've been pleasant to deal with, accommodating and responsive.  This job is unusual, but they were keen to tackle it.  

As bonus content, here is a little video of dancing sprayfoam guy:

SuperGreen Laneway house construction progress pictures

As with most blogs, I had the best of intention to post a bit more regularly.  But June got really busy with work and other parts of "life" and so have fallen off the wagon.  To catch up a bit, I've just posted a series of construction progress pictures over this month, complete with captions describing things of interest.

Foundation with mudsill installed, ready for framing to go up.  Note 3" square cut washers on anchor bolts.  These are to provide better hold-down of the building during large earthquakes and is one of the earthquake resistant design elements of this home.

Another view of the foundation.  Garage area has been backfilled.  The sump is visible in the basement (foreground) which is to lift both the basement floor drain and under-drain up to the sewer line because the sewer is higher than the basement.  Also you can see a 4" ABS stub to the left of the sump - this is the vent pipe tied to the under slab radon venting system.  It is unlikely the radon vent will be required due to the tight construction, but the vent piping is added now because to add it later would be a real problem!

Floor and first wall put up.

This laneway house replaces an old garden suite.  It uses the same sewer and water connect as the original garden suite - which is plumbed through the house on the front of the property!  The original suite used a heat-trace on the water line to prevent freezing.  We've replaced it with two waterlines (insulated black pipes on the left) to allow for a re-circulation system to prevent freezing.  This is yet another energy conservation measure because re-circ uses significantly less electricity than heat traces. 

6" of perimeter insulation is installed over the shallow footing of the garage to frost-protect the footing.  At the corners this insulation extends 3-feet from the building.  We've re-used extruded polystyrene insulation that was salvaged from the roof of Porter Creek High School last year. 

Another view of the frost-protected footing insulation being installed.  Note the drainage gravel below which encapsulates the perimeter drainage pipe.  This is water management component of the building's comprehensive durability plan to help ensure a dry, long-lived home. 

First floor framing up.

2nd framing going on.  Building has continuous plywood sheathing again for durability and earthquake resistance.  I'm starting to see many builders switch from OSB back to plywood sheathing.  Continuous OSB sheathing is pretty good, but plywood is slightly better as it performs better if it gets wet.  

Interior of garage portion.  Note that tall I-joists are used for second floor.  These are larger than is needed for the short span, but it allows for large cut-outs in the I-joists to pass the ventilation duct work through.  This keeps the mechanical nice and neat, avoiding unnecessary boxed in duct chases.  The primary ventilation duct runs are preplanned and installed - visible in this photo. 

Guest room area on main floor.  Partition wall to garage is a staggered stud wall (right side of photo) for extra insulation and reduced sound transmission.

 

Another view of the garage.  Note 4.5" of closed-cell spray foam has been applied to the earth.  This provides both the vapor/capillary barrier and insulation for under the garage concrete slab.  It's also pretty nice to work on during construction.

The second floor has a small cantilevered box window in the bedroom.  This is a few of the framing used to support that cantilever.  I inspect all of these connections and hardware to ensure all required nailing is in place (again, nailing inspections is another durability plan element).  It is quite surprising how often nails are missed.  I shutter to think how much nailing is missing in conventional production-style homes!

Roof trusses going up.  Trusses had to be craned from the street, over heritage house at the front of the property!  Note the window and door extension boxes are installed (one with Bluskin for waterproofing).  These are to extend the windows and doors outward when the 8" of exterior closed-cell sprayfoam will be installed later.  

Roof trusses being installed.  Truss tails are pre-painted because they will be exposed when the home is finished.  A Craftsman-style home detail where the soffits are open and the rafter tails are visible.

Super-Insulating a Basement?

We've just finished the foundation and basement of our little SuperGreen Laneway house.  This includes a "super-insulated" basement. 

Why do that you might ask?  

Additional perimeter R25 insulation on Insulated Concrete Form (ICF) basement ready for backfill.

We know from recent work by Mark Carver at NRCAN and Energy Solutions Centre on their cost optimization study that basement insulation has less bang-for-the-buck than above-grade wall insulation.  This makes sense because the temperature differential between inside versus cold winter air of the above grade wall is much higher than the basement to ground temperature differential.  Higher temperature differential means higher heat loss (which is why keeping your house cooler inside reduces heat loss).  

The challenge however with building a small SuperGreen home is the space.  Because of all the insulation, the walls get quite thick. This makes it hard to keep the home small and fit it on the property.  There are limitations to practically how much insulation you can install.  This leads you to find places that are convenient to stuff lots of insulation, but won't compromise the design of the building.  A common example of this is the ceiling.  When looking at where the heat loss in a house is, the ceiling/roof really is a small portion of the heat loss.
So why do we heap the insulation so high in the ceiling (i.e. R100 or more)?
Because it is a cheap and easy place to pile up a lot of insulation, even though its effectiveness is definitely on the upper end of the diminishing returns curve.
 

ICF Basement/foundation ready for concrete

In the SuperGreen homes we've built we've been using Insulated Concrete Forms, or ICF, foundation/basements.  This gives a very resilient concrete foundation below grade, but is relatively easy to build and and gives you and insulated concrete basement.  The standard ICF block we use have about 5.75" of expanded polystyrene insulation.  This gives about R26 (with no thermal bridging).  In our last building, we then used an interior stud wall with additional batt insulation to add another R22 (making the wall R48).

ICF Basement braced and ready for concrete.

The problem with insulating on the inside is it eats up floor space.  In small home, this is undesirable.  When designing our new SuperGreen Laneway home the light-bulb went on:  Why not insulate on the OUTSIDE of the basement.  A product called "Terrafoam HS-40" by Beaver Plastics (made in Alberta) is commonly being used now in the Yukon for below-grade insulation.  It is specifically designed for this perimeter insulation and sub-grade application. 

Eureka!  We found it - here is another place, much like ceilings, where we can stuff lots of insulation without taking up space.  Since this will all be buried outside of the building footprint, this this an easy place were we can put lots of insulation without affecting the design of the rest of the building.  Yes, it is an area on the upper-end of the diminishing returns curve.  But when you are pushing the energy-efficiency envelope, we need to find these low(er) hanging opportunities. 

So our design calls for 5" of HS-40 insulation outside of the ICF.  The manufacturer claims it is R-5 / inch at -10C.  (The weird thing they claim is its R-value goes up the colder it gets.  That's nice!)  So this gives an extra R25 ontop of the ICF's R26 for a total of R51 basement.  Not quite R60 of the walls above, but getting closer.

Once again pumping concrete OVER the "heritage" house to fill the ICF foundation.

Below is the footing detail that shows how the insulation is installed.  Note that the second 2" layer laps over the footing, insulating the footing too.  Now keen observers will note a thermal bridge in this design between the slab and the footing.  Yes, I know it is there, and for a variety of reasons (that I don't have the energy to describe), I designed it that way for this particular building.

Footing detail showing exterior EPS insulation around ICF basement.

 Below are a few additional pictures of the waterproofing and extra-insulation installation details.

Self-adhering waterproof membrane installed on ICF.  The membrane laps over footing and ties into the poly wrapping the footing as a capillary barrier.

1st and 2nd layers of exterior insulation being installed.  Note how second layer laps over the footing to insulate it. The little bits of Tuck Tape (red tape) are just there temporarily to hold the insulation in place.  Once it is backfilled against, the insulation won't be going anywhere.

Another view of the below-grade exterior insulation around the garage portion of the house, ready for backfill.  Note the interior PWF cripple wall to support the garage slab.  The stud-bays here too have been filled with 3.5" of EPS insulation.