Perform an energy assessment
The LiveSmart BC program administered by the BC Ministry of Environment provides a number of great ideas to improve the sustainability and efficiency of your home. We had a Certifed Energy Advisor come to our house before construction to perform an energy assessment and provide us ideas on how we could minimize our environmental footprint. This comes with a number of energy rebates, whcih could provide us up to $5000 in savings. We're doing it for sustainability reasons... but stay tuned for the final score once we are complete... perhaps this program will be worth it for us! Also see BC Hydro's Powersmart tips - other than downsizing our home ;-) we found lots of great ideas there too.
UPDATE: Just had the energy audit. Took them a while to model the house given the changes, but here are the main paragraphs from the letter from the auditor...
"Congratulations on taking steps to make your house more energy efficient. Here are the results of your follow-up assessment:
Before:
Energuide Rating: 37
ACH @ 50pa (Air changes / hour at 50pa): 10.52
Equivalent Leakage Area: 2845cm squared
After:
Energuide Rating: 84
ACH @ 50pa: 3.04
Equivalent Leakage Area: 1374cm squared
There has been a tremendous improvement in the air-tightness of your home since the first blower door test was conducted which is not surprising since the the entire house was rebuilt. The energuide rating and the air tightness characteristics of the home is the highest I've seen out of the 550 homes I've done energy audits for. As a home gets larger, and everything else stays the same (building envelope characteristics and heating system), the energuide rating drops since it requires more energy to keep the living space conditioned.
It's quite rare to see a large house like yours have an energuide rating over 80. Credit goes to the efficient heating system, insulation and of course the well constructed building envelope. Another homeowner in North Vancouver came very close with an energuide rating of 82 and an ACH@50pa of 3.65 but had a tiny 2000sq foot house.
With your upgrades, you will be benefiting from decreased utility costs, a more comfortable living space, the resale value of your home has increased, and most importantly - your home will be having a lot less impact on the environment."
... goal achieved, and more!!! Especially having added 1,000 sq. feet!
Returning rainwater to the ground
Its all too easy to redirect rainwater and pooling groundwater to the municipal sewer system or the street, and back to the ocean. But our concrete jungle is quickly removing the natural ability of the earth to return precipitation to the ground for the benefit of plants, trees, creeks and rivers - and the associated riparian habitat. A few things we employed that will really make a difference here: maximizing the use of grass and planted beds to capture soil; using stone and concrete to capture and redirect water to the plants; using paving stone, pea gravel and grass for large expanses of driveway and paths (versus concrete or asphalt that prevents natural drainage); and finally, capturing all the rainwater from the roof area and excess groundwater, and returning it to a central sump drain where it can drain naturally into to soil and underground aquifers (see section on plumbing for more details).
Avoiding hazardous materials
The first thing we did at the outset was remove all hazardous materials (such as asbestos in old drywall, linoleum, textured ceiling materials and insulation). Albeit a complex and expensive step - we feel so much better living in a house that doesn't contain these carcinogens! Next step was to make sure that the new building materials we as natural as possible, minimizing the chance of introducing offgassing and future health risks for our family. Generally speaking, materials that contain such gases are usually the type of products that create all sorts of environmental issues during production and construction! Now the downside of this strategy is that you may find the budget goes up - for example, using natural pine interior trim is generally more expensive than manufactured MDF board... but hey, the real stuff is way better anyway and is likely a good use of pine beetle-infested wood that wouldn't otherwise be usable!
Greywater Heat Recovery
Ever thought about how hot your pipes get when you pour hotwater down the sink or from the bath/shower? A water heat recovery device is a simple copper coil wrapped around your drain pipe. Cold water from the municipal service passes though the copper coil on its way to your hot water cylinder. As hot water goes down the drain it heats the incoming cold water, significantly reducing the load on the hot water system. Aside from gaining some energy rebates, this can reduce your hot water heating bills and associated unnecessary energy consumption by by up to 50%. NRC estimates the payback is about 2 years. Ours arrived in wooden packing cases today... very cool. (see our watercycle technology here). All the waste water will run from showers and baths through the watercycle copper pipe set in foam insulation:
Interesting quote... "According to U.S. EPA standards, if just 6 million electric water heating systems were to be upgraded by GFX, carbon dioxide emissions would drop by more that 20 million tons per year; the amount released by burning 1.8 billion gallons of oil."
Gas or Electricity?
In Vancouver, our electricity is generated by natural hydro power- generally the cleanest of the mass-generated electricity options. The cost of gas is predicted to continue to escalate, but climate change seems to be continuing to feed our dams indefinitely here! So electricity is probably our best long-term heating strategy. This is supported by BC Hydro's focus on alternative power generation, and certainly means our house will be pre-wired for any future alternative energy strategy (such as solar or fuel cell). We'll continue to use gas for fireplaces and range top (could have chosen induction cooktop, I guess... but you've gotta have one weaknesses... and a beautiful gas range is it)!! Our army marches on its stomach! The gas range with electrical wall oven is pretty efficient. The gas fireplaces use electronic ignition and minimal pilot lights - which fortunately are becoming a thing of the past on furnaces and hot water heaters too.
Heating strategies
The cornerstone of our heating strategies are:
- insulate the house so its airtight (which is ok in combination with an HRV system - see below).
- use spray foam insulation in exterior and hard to reach cavities to maximize heat retention.
- all external window/door frames, cracks and gaps are sealed with Blueskin.
- install an air-source heat pump to provide energy efficient heating in winter, and cooling in summer.
- install a high efficiency electrical furnaces (yes, multiple smaller units) with variable speed fans.
- radiant underfloor heating provided by hot-water pipes from heat pump/furnaces placed under joists.
- returning hot water to the hot water cylinder,supplemented by watercycling heat exchange technology.
- install energy-efficient ('Low E') windows to maximize the natural light and heat, but not too much!
- Wide overhangs to shade the rooms in summer, but allow the low sun to stream in on winter days.
- install a heat recovery ventilation (HRV) system to recirculate fresh and heated/cooled air.
- install energy-efficient gas fireplaces (attractive, but also useful if there is power outage in winter!).
- ensure gas fireplaces use convection heating, not noisy energy-hogging blower fans.
- designing the house so heat is trapped in the vaulted ceilings for recirculation and re-use.
- placing cold air return furnace vents near sources of heat (eg. fireplaces, etc) to minimize re-heating.
Our furnace system is a very efficient design (http://www.unicosystem.com/). Essentially the heat pump (http://www.daikin.com/) outside heats/chills hot water into a holding tank (much like a hot water tank).
This hot or chilled water is distributed to three fan units in different places in our home. We placed these small electrical, energy efficient fan units in the garage, the attic and the crawl space. The piping to these units is installed under the subfloors of bathroom, creating natural bathroom floor heating without highly inefficient underfloor heating mats. These high velocity fans blow the water heated/chilled air into the bedrooms using normal furnace ducting. Using these three units, plus gas fireplaces and the HRV system creates zones in the house, controlled by 7 thermostats. This is far quieter, economical and energy efficent than treating the house as one zone with one large furnace supporting it all.
One advantage of an electrical furnace is the ability to use the variable speed motor as a low energy, low speed fan to support constant air recirculation (heated in winter and cool in summer). The Eneready HRV system will drive the recirculation of air, allowing us to avoid those noisy bathroom exhaust fans (silence is golden) and quickly extract all polluted air or super-heated steam - while exchanging the heat with the in-coming cold/fresh air, warming it up before it gets to the furnaces. This warm air is re-used to heat the house, saving further energy costs and minimizing emissions into the atmosphere.
Here is the black rubber/pex piping running from the heat pump to the furnaces under the bathroom floors, which has been now been insulated with a layer of fibreglass insultation. This will trap heat emitting from the pipes in the closed area between the joists and radiate warmth up through the subfloor and tiles in the bathrooms above. This also eliminates the need for heated underlay or furnace ducting into these rooms. In effect, its free heat as the water has to circulate between the heat pump and furnances anyway!
According to the NRC stats, all these combinations of heating and insulation will reduce our heating bills by up to 50% and our greenhouse gas emissons by up to 93%!! Certainly having no more 'holes' in the house expelling heat and GHGs is a big factor over what we had!
Insulation
All the exterior cavities and walls were spray foamed to ensure it is impossible for air to escape. Although its a lot more expensive than traditional insultation materials, its fast and much more effective. Also allows us to get into tough corners and cavities. Cool colour too....!!
All the ducting pipes were then spray foamed to ensure no heat loss from the heating system.
To increase the R-value, normal pink batt insultation was stuffed into the cavities. All doors and windows were sealed with insulation rods and silicone sealant. The house is now completely air-tight!!
In addition, any water pipes in cold spaces such as exterior walls or attic space were surrounded in thick hard foam board and sealed. No more luke warm showers!!
Well, after plenty of research, its fair to say that eco-friendly and contemporary are not often found in one place. Its hard to find decent fixtures without them looking like they came off a sailboat toilet!! Try doing a search on any popular brandname, then click the eco-friendly/watersense option... you drop from 20 pages of examples down to 3 individual examples!! However, we have stumbled on some pretty cool products. In the relatively high-end brands, it appears companies like Toto and Kohler have some great examples of low-flow toilets, for example, that use less than 1.6 gallons per flush. In the case of the Kohler toilets, water is also supplemented with air pressure - basically like an aeroplane toilet - eliminating the need for the dual-flush option. Well done guys... keep investing in that toilet technology research! On the other fixtures, after looking at all the high-end brands, our interior designer suggested an up-and-coming Canadian company (from Saint-Jérôme, Montreal), called Riobel. We were pleasantly surprised to find this 15-year old classy company has an amazingly deep product range (all solid brass and ceramic cartridges, etc), and a real commitment to water ecology. Keep on eye on these guys in the future!
Green electrical
Other than the obvious fact that Vancouver's electricity comes from clean, green hydro, our plan is to implement some energy efficient solutions. We have maximized our use of low voltage lighting, and dimmers to further reduce energy consumption. Using a heat pump to heat water through pipes under the floor and into high velocity fans provides significant room heat for very little cost. Operating three fan units and four heating zones in the house ensures an even distribution of heat - certainly more so that one very large furnace trying to heat the entire house evenly.
Splitting the sub panels and putting one of them in the garage not only allows for shorter electrical wiring runs, but also reduces the amount of wire in the house. It also allows us to place electrical outlets in the garage in the future for electric cars. Won't be long before this is a municipal code for new construction, and I'm sure our children's first vehicle will be electrical - its only 4 years away!!
Green flooring
Well its not actually green... its walnut! Given the air tight, energy efficient nature of the house, we were able to eliminate all unnatural floor coverings (except for some 100% wool carpet in the media room, where accoustics is critical). This also eliminates the off-gassing from manufactured, petroleum based chemicals. The floors are all thick 5mm enginneered white oak on 10-layer plywood. This stuff is 3x harder than solid wood, quicker to lay, stronger laterally, same maintenance and looks fantastic! The hardwood guy was one of the best tradesman we had (probably right up there with the framer, finish carpenter and the tiler). He would spend an entire evening in one bedroom on his knees with a belt sander getting the finishing perfect. He would wet mop the floor to bring up the grain, then polish with steel wool. After a coat of water-based stain, he would sand with 200-grit paper and repeat the stain/sanding process a couple of times. Wow - the floors are rock solid and have come up polished like the kitchen cabinetry. Best part is the lack of glitzer and other oil-based chemicals!