Designing Homes for Passive Survivability

Superstorm Sandy me reminded me about the idea of "Passive Survivability" in building design.  And then I noticed an article in www.greenbuildingadvisor.com on building for resilience called "Gas Lines Point to Need for Resilience" - a good read, check it out.

Passive Survivability is the idea that in the case of disaster (power outage, short or long, earthquake, etc.) that your home is inhabitable, protecting and sheltering you in difficult times.

In designing homes for the Yukon, there are a number of very simple strategies that can and should be incorporated to generate "Passive Survivability" in your home:

1. Design and build the home that is likely to physically survive the disaster, such as flood, fire and/or earthquake:

• Flood is obvious - don't build on a floodplain or low down, next to water!  

• Fire, especially wildfire, is pretty well understood by Yukoners and I don't need to cover reducing and managing fire risk at your home as that is well addressed elsewhere.  However, do think about cement board siding (e.g. HardiePlank or equivalent).  Ever seen vinyl siding when it gets "warm" - scary! 

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  Homebuilders' Guide to Earthquake-Resistant Design and Construction

  Earthquake resistant design is recommended.  Earthquakes are a threat in southern Yukon, so we should include design and construction elements to our buildings to give them a better chance of surviving "a big one" when we get hit.  The US Federal Emergency Management Agency (FEMA) has an excellent document for home builders called Homebuilders' Guide to Earthquake-Resistant Design and Construction.  It is very practical and has lots of good things that are very easy and inexpensive to do in the design and construction of a home that is going to make it much more likely to survive an earthquake.  Whitehorse is probably in a Seismic Design Class (SDC) of C or D1, which means that earthquake resistance measure really should be incorporated.  We did this in the SuperGreen duplex build in Takhini North, and it was very easy to do - just need to pay attention to the details.

Example of superinsulated wall.  Note wall thickness shown by double-doors

 2. Superinsulated building - so when the power goes out, the building stays warm. Seems obvious--put lots of blankets on your home so you stay warm for a long time.

By superinsulated, we mean EnerGuide 85 - so using half the heating requirements of a conventional new home in Whitehorse.  R60 walls, R100 ceiling, best windows you can get, and a very air-tight building envelope, etc.  We've covered the super insulation thing enough here on this blog, so no need to say more.

3. Wood heat - consider including a wood stove in your home.  Again, when the power goes out, a wood stove is the only off-the-shelf heating system that will easily work without power.

Also, think about using a propane cook stove & oven.  You can light them and cook even when the power is out. 

WARNING - use of a propane cookstove indoors without adequate ventilation presents a health hazard.  So when the power goes out, make sure you provide adequate ventilation by opening windows because you mechanical ventilation (rangehood and HRV) won't be working!

At minimum, have a barbeque and an extra tank of propane.  

Extra-large hot water tank can provide water in emergencies

4. Oversized hotwater tank - If the power and water goes out, you have lots of water stored in that tank.  Make sure the drain is accessible of course.  Another good reason that on-demand hot water heaters don't make sense in the Yukon.  Don't worry about the standby losses from the hot water tank.  You need the heat in the home at least three-quarters of the year, and with a superinsulated envelope, you are not wasting any energy.

In the photo to the right, there is one thing missing though - seismic tie-downs on the tank!  You don't want to loose your precious water in the case of a large earthquake by your tank tipping over.

Windows at each stairway landing for light

5. Windows in all rooms to provide natural light, especially windows in stairways.  If you have windows to provide even some natural light to all rooms in the house, then when the power goes out, you will still be able to move around.  Locating your stairs so you can have windows is an important design consideration so you can get out of the house in the dark.

Infloor heating tubes layed out ready for basement concrete slab

6. Think about installing in-floor heating in the basement floor concrete slab for thermal storage.  If you are pouring an insulated, concrete slab for the basement add in-floor heating tubes to use the basement to not only provide comfortable heating to the basement, but also "thermal storage" in the case of power/heat outage.  The bulk of the cost for this is the concrete floor, which you are pouring anyway, so adding the tubing is a small incremental cost for a "heat-insurance" plan.

With a super-insulated home, a heated up slab can keep the house warm for days even during the coldest weather as the slab radiates the heat stored up in the slab.  We figured this out first hand accidentally.  I inadvertently turned off our heating system one winter (it was -35C at the time) and it was for a couple of days until we realized the heat was off!