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! 

• 

  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! 

 

Updated Home Heating Energy Graphs

With winter and heating season on us, the good folks over at Yukon Housing Corp have updated the their home heating energy cost graphs. Check them out at:

http://www.housing.yk.ca/energycosts.html

People are always asking "what is the cheapest way to heat my home" - these graphs give the up-to-date answer. It is important to watch these trends, because things are always changing. What we "knew" about home heating 5 years ago no longer holds true - so keep you eye on our energy cost trends! These graphs show the all-in cost of energy, including the efficiency of the appliance that give you the actual heat delivered, allowing you to compare apples-to-apples. Probably the most useful two graphs for Whitehorse homeowners is graph #1 - Home Heating Costs vs. Heating Appliance Efficiency. The other one to check out is graph #13 - Whitehorse Historical Residential Heating Costs at 80% Fuel Use Efficiency . This latter one is important because it show energy cost trends we've actually experienced over the last 10 years.

What are some key observations?

· Pellet prices have been steadily rising. If you have a low efficiency pellet stove, it could actually be more expensive than electricity.

· Oil and propane remain the highest cost option, especially if you have a low- efficiency furnace- even with the increase in electrical rates.

· Propane costs have dropped a lot lately and now are similar in energy cost to both oil and 2nd block electricity (Propane used to be the most expensive option).

· Overall, oil fuel prices have tripled since 2000 and continue to show high price volatility.

· We've moved to the 3-tier electrical pricing and electricity costs have jumped slightly, although still remain the lowest cost energy, especially first block energy. Remember you get the first 1,000 kWh at the low rate, then everything above that is higher. I think most people if using electric heat will definitely go into the second block, but won't be using a lot at the top rate.

· Another interesting thing is to look at the energy costs, particularly electricity and propane, that other customer classes pay (government for example) are vastly different that what we pay as home owners. Look at propane - the government is only paying $0.38 / L where homeowners are paying $0.84 / L - wow, that's a big difference!

LEED Gold - Yukon's First LEED Canada Certified Homes

Well, after a year of waiting, we finally got our LEED^® Canada for Homes Certification for the SuperGreen Duplex we built at 38 & 40 Nijmegan Road.  As we talked about before, this is the first LEED^® Certified home in the Yukon, and the second LEED^® certified building in the Yukon (the first was the Taku Building on Main Street, and I think they beat us by only a couple of weeks!).  If nothing else, I can say that the process was thorough, taking almost longer to complete the certification that it did for us to build the homes!  Pretty much every suststainability claim we made was verified by the Provider before submission to Canada Green Building Council.  And I think because this was a Yukon first, they were extra diligent.

Anyway, if felt good to finally screw the LEED^® plaques to the building, knowing that we've raised the bar, but at the same time made some high quality affordable housing, and most of all, that the owners/tenants of the SuperGreen duplex seem to be very happy and satisfied with their homes that will last generations.

One Year in a SuperGreen Home

We've now got a whole year's worth of energy usage data from the SuperGreen duplex.  And the results confirm what the earlier trends showed - this home is using even less energy than predicted, about 30% less!
Results are shown for 38 Nijmegan below (special thanks to the owners for sharing the energy usage data).  We also have almost a full year from 40 Nijmegan, the other half of the duplex.  And it shows the same trends - about 30% less energy usage.  So this tells us it is not just a fluke or entirely occupant behaviour--in fact the buildings are performing consistently better and anticipated.  

The graphs below shows predicted energy usage (shown as bars) versus the actual total energy usage in the duplex (shown as a green line) for the months for a whole year.  The red line show is the energy usage of a similarly sized conventional new home in Whitehorse.  Actually energy usage has been "normalized" to take of the fact that much of this year's winter was pretty warm.  So this is adjusted to average weather conditions.

SuperGreen Energy Usage Versus a Conventional Home
For comparison purposes (and to help illustrated the predicted versus actual energy performance of the building) the energy usage of a similarly sized, new home in Whitehorse is shown on the graph as the red line.  This represents an electrically heated new home built in compliance with the City of Whitehorse’s energy efficiency bylaw.  By way of comparison, over the year, total energy costs for the conventional, electrically  home would have been $3,920.  The actual energy costs over the same period for the SuperGreen duplex have only been $1,390.  That is less than half the energy cost – a savings of $2,530 in just one year!

Yukon's Reservoir Levels - April Update

I've been skipping a bit of winter and haven't done an energy battery update in sometime - but this is the time we really draw down our stored renewable energy, and things get lean in the spring.  

Marsh Lake is looking quite low, about 2/3 of what we normally have at this time of year, but Mayo and Aishihik lakes are fuller than average; overall we aren't too far below how much water we normally have at this time of year.  Right now the overall energy stored is down to 33%, about 2% lower than average for this time of year.  Probably the warm February and March this year kept demand down even though we're a growing community. 

Let's hope for a quick, warm spring!