As is our custom, the conversation eventually shifted to construction and our plans to build green homes at Sarilia.

Mark commented that he had recently seen an LED light bulb at Walmart. The package claimed that the bulb would replace a 40 watt bulb and used only 3 watts of electricity. Life expectancy of the bulb is 40,000 hours.

When I asked my friend if he bought the bulb, his comment was ‘I can’t afford a $15 LED light bulb’. He bought the incandescent 40 watt light bulb with an estimated life of 1000 hours for $1.

Being an accountant by training, I can’t resist the opportunity to analyze Mark’s decision: Lets assume that Mark uses the light bulb about 4 hours a day.

At 4 hours a day, the LED will last 10,000 days or just over 27 years. During that same time period, Mark would have to change his incandescent light bulb approximately every 9 months or 40 times in the 27 years. So, at today’s prices, the incandescent light bulb would actually cost $40 over the 27 years while the LED will cost $15 once. Total savings of $25 on the cost of the LED vs the incandescent bulbs.

The LED uses 3 watts per hour or 12 watts per day. In 27 years, the LED will burn 120 KWhs of electricity. The incandescent bulb burns 40 watts per hour or 160 watts per day. In 27 years, the incandescent will burn 1600 KWhs of electricity. Mark pays about 11.4 cents per KWh for electricity so at today’s prices, the LED will cost $13.64 for electricity and the incandescent will cost $182.40. Total savings of $168.76.

The term ‘PassivHaus’ refers to a voluntary, ultra low-energy construction standard first developed over a decade ago by Dr Wolfgang Feist of the Passivhaus Institut Germany.

The objective of PassivHaus design is to reduce the requirement for spaceheating and cooling. This can be achieved without compromising comfort.

To achieve the PassivHaus standard the energy required for space heating must not exceed 15 kWh/square meter/year (1.4 KWh/square foot). To give you a sense of this, a 1500 square foot home achieving this standard would have an ANNUAL space heating bill of  $51.45 (1500 sq feet*1.4KWh/square foot/year*$.0245/KWh for natural gas (in Saskatchewan, March , 1009))

Achieving a space heating requirement of 15 kWh/(m2 a) or less means that the following technologies are required:

• Super-insulation: opaque U-values must be less than 0.15 W/m2K (equivalent to greater than R 38
• U-values for windows and doors need to be 0.8 W/m2K or less (equivalent to R7 or more) for both the frame and glazing. This requires the window frame to incorporate insulation and triple glazing
• Thermal bridging needs to be minimised, and ideally eliminated. A thermal bridge is created when materials that are poor insulators come in contact, allowing heat to flow through the path created.
• Airtightness: n50 of 0.6 h-1 @ 50 Pa or less
• Whole house mechanical ventilation with heat recovery (75% efficient or better, with a low specific fan power).

• Domestic hot water – energy used to heat water for day to day use in baths, showers, washing, etc.
• Space heating/cooling – energy used to heat or cool the home.
• Appliances – energy (usually electric) used for lighting, appliances, and mechanical.

A typical Canadian home uses between 25~33% of their energy heating domestic hot water. The easiest way to reduce the energy you use heating hot water is to reduce the amount of hot water you use.

In their 2004 booklet on Water Conservation, Carbon Dioxide Reduction Edmonton identifies a number of strategies available to reduce the amount of water and more specifically hot water used:

• Repair any leaking faucets
• Install low flow shower heads
• Install low flow faucet aerators
• Purchase Energy Star clothes washer and dish washer.

A leaking faucet dripping only one drop per second will waste 8000 litres of water per year. If this is hot water, the cost is even more significant. Repairing any leaking faucets is an easy and cost effective way to save energy.

Low flow shower heads will reduce hot water usage by 30 to 50% without significantly reducing the feel of the shower. These are inexpensive to purchase and easy to install.

Figure 1 – Source CORE : An inexpensive flow restrictor and be installed to reduce the water flow rate by 20~30%

Low flow faucet aerators thread into existing faucets. They reduce flow rates by up to 50% by mixing air into the water. This can translate into overall water savings of 30% on a typical faucet.

Front loading Energy Star clothes washers will use 30-50% less water than regular clothes washers. They also do a better job of extracting water from clothes during the spin cycle which will further reduce energy costs related to drying clothes. Energy Star dish washers use at least 25% less water and can save 20% on heating costs by heating incoming water.

So what are we waiting for? Proven technologies are available to reduce hot water consumption in your home. Reducing hot water consumption will reduce the amount of energy you use, save you money and lower your green house gas emissions.

Looking at out greenhouse gas emissions helps us understand where we fit into the picture — and in fact, what we can do to change. The Conference Board of Canada (www.conferenceboard.ca) ranks Canada very poorly in the area of greenhouse gas emissions:

‘Canada is one of the world’s largest GHG emitters. Canada ranks 16th out of 17 OECD countries on GHG emissions per capita and scores a “D” grade. In 2005, Canada’s GHG emissions were 22.6 tonnes per capita, almost double the 17-country average of 12.4 tonnes per capita. Canada’s per capita GHG emissions were also almost four times greater than Norway’s, the top performer.

While Canada’s GHG emissions per capita have risen since 1990, Norway managed to decrease its GHG emissions per capita by 30 per cent between 1990 and 2005.’

Figure 1 – Canada Conference Board report card on Canadian Green House Gas emissions

I have lived in Saskatchewan all of my life. I always thought of us as a green, environmentally friendly society. It came as a big surprise to me that Saskatchewan is actually the second highest greenhouse gas emitter in the world. According to the Saskatchewan Environmental Society (www.environmentalsociety.ca) we are at 72 tonnes per capita. This is nothing to be proud of. We typically blame our climate but Scandinavian countries like Norway, Sweden, Finland and Denmark have similar climates and they are doing much, much better than we are (see Conference Board of Canada report card above)

Residential energy use accounts for 16 per cent of total energy use in Canada. But there are ways to reduce this impact. For example, if we look at the Riverdale Net Zero Home (see my November 11, 2009 blog),  the average home in Saskatchewan would  be responsible for nearly 17 tonnes of greenhouse gas emissions per year.  This assumes an R2000 construction standard.  Of course, most new homes are not built to the same green standard, even though it’s possible.

So what are we waiting for? Proven technologies are available to eliminate or minimize energy use in residential housing. Reducing your energy use clearly saves money and reduces green house gas emissions. We need to start using these technologies to do our share for the environment. We need to build green.

Mark and I both found the home quite attractive in a unique way. Mark (18) commented; ‘Cool – I would love to live in a house like this.’

A lot of Net Zero homes are criticized for their appearance. The challenge is usually with the placement of solar and PV panels. The Riverdale Net Zero home in Edmonton is an example of a home that was challenged with the need to put the solar panels on the front of the house.

I have heard a lot of controversy over this design. I have toured the Riverdale Net Zero Home and it actually looks quite attractive and fits in with the very modern architecture of the homes in that area.

Other Net Zero homes look like any other house on the block. The Mill Creek Net Zero Home is an example:

The back yard of this home faces south so the solar panels are all located at the back. If you look carefully at this picture, you can spot the solar panels on the roof at the back but other than that, you would never know that this is a Net Zero Home.

The CHESS net zero home in Red Deer used a different strategy and integrated their solar panels into the roof line. The solar panels are visible from the street but more integrated into a standard design:

As you can see, NetZero homes come in all shapes and sizes. The variable appears to be the cost of one design over the other. Please take a moment to let me know your thoughts on these 4 designs: Which would you prefer to live in? All are Net Zero Homes but the Michelle Kaufman home would be significantly more cost effective (probably 25% less per foot than the others). Would that affect your decision? You can contact me at ronn@ronnlepage.com.

The Building Saskatchewan Green conference was in Saskatoon last week. Although I could not attend the entire conference, I did get a chance to attend the Friday luncheon and visit the expo.

I always find the expo to be the most interesting. I feel I can get a  sense of what is happening in the market by who is at the expo. The following are some of my observations:

• There were 3-4 solar hot water companies. All of them claim to be very busy. My friend Brent Veitch from Rock Paper Sun is booked up well into the new year.
• A number of booths were offering Photovoltaic options. Prices still are very high for this technology. One provider had an offer for a 2.6KW on gird system for about $26000.
• Affinity Credit Union had a large booth promoting special financing for green residential construction projects. They did not have a lot of detail but advised that I contact one of their many branches.
• SaskPower/SaskEnergy had a booth promoting their loans. Of special interest was a low interest loan of up to $50000 for renewable energy systems such as wind, solar or geothermal.
• WSE Technologies was showing some of their new product lines. They are carrying a number of new products that are worth considering. I am meeting with them in the next few weeks to get a better understanding of their products and services
• At least two Integrated Concrete Form manufacturers were represented. One promised to send me more information on their product. I will be doing a blog on ICFs in the near future
• Rick Olmstead, the inventor of heat exchange ventilation systems had a booth. You may also know Rick as one of the principals in the Rivergreen Ecovillage project.

Sometimes it is interesting to note who was not there:

• Window technology is a very important part of any passive solar strategy. There was no one there from the window manufacturers
• Structured Insulated Panels (SIPs) are being positioned as a green building alternative. No SIPs manufacturers were represented

I really enjoyed the time I was able to spend at the conference. Next year I plan to be there for the full day.

On October 15, I had the opportunity to attend a green roof workshop at the center in Vancouver. The workshop was led by Jonathan Hays,  the technology transfer coordinator for the Center.

There are two types of green roof designs:

• extensive green  roofs use a vegetation layer between 2 to 6 inches deep. This shallow planting medium reduces costs but restricts the type of vegetation that can be planted.
• Intensive green roofs have a much thicker vegetation layer. This design is much costlier but allows for unique designs and public access.

Construction techniques have been well tested through experience in Europe. The diagram above [taken from CMHC’s “Green Roofs -  a Resource Manual for Municipal Policy Makers”] shows  the multiple layers required for the proper construction of a green roof.

The Center  at BCIT  has an extensive green roof with one third of the roof using a 3 inch  vegetation layer, one third using a six-inch vegetation layer and the remaining one third left open as a control area.  The center also tests a number of other roof types in several roof emulation modules [REM].

My conclusion after visiting the center is that green roof  technology should be considered for any flat roof commercial buildings but that is not yet ready for residential use in Canada.

For more information on green roofs, check out www.BCIT.ca/greenroof

Dr. Dumont is from Saskatoon and has spent most of his career studying energy efficient home construction. We are planning to build a net zero demonstration home at Sarilia Country Estates (www.sarilia.com) and we are very fortunate to have Dr. Dumont on the design team.

figure 1: from presentation by Gorden Howell on the Riverdale NetZero home

In his January, 2003 article in SOLPlan Review, Dr. Dumont outlines the integrated design process:

1) Define the design goals – every owner has different goals for their home. It is important that everyone on the design team understands these goals.

2) Be quantitative with goals where quantitative criteria are appropriate – goals should be quantified in a number of areas:

• • energy related goals
  • air quality related goals
  • water conservation goals
  • natural lighting goals
  • recycling and solid waste management goals

3) Proceed with integrated design

The integrated design session for the Lepage NetZero Home is planned for Monday October 5. Our preliminary design objectives follow:

Figure 2: from Lepage NetZero Home – Planning phase

We are very excited about our NetZero Home and the opportunity to work with Dr Dumont. More to follow …

I recently met with my good friend Bill Matiko to discuss his recent home project. Bill is building a beautiful home on a small acreage just outside of Saskatoon. Although he never planned for his home to be a Net Zero Energy home, Bill carefully designed his home to be energy efficient.

A Structural Insulated Panel (SIP) is a panel composed of expanded polystyrene insulation (EPS) board laminated between two sheets of oriented strand board (OSB).

I was researching the use of SIPs as a construction strategy for super insulated homes (R50~60 walls, R90~100 ceilings). Bill had used SIPs in his home and I wanted his opinion.

Bill reported that the SIPs were a charm to install. He took a one day class on how to install them and he and one other guy were able to set up all of his walls in less than three days. He felt that the materials were superior in quality and that they were very well engineered for easy installation. No vapor barrier is required and the walls were designed for easy installation of electrical systems.

SIPs provide a higher insulation value than regular wall construction. The specifications of one leading manufacturer indicate that a 6.5 inch SIP has an R value of 24. This is about a 25% increase in thermal resistance over a typical 2×6 wall construction that would have an R value of about 19.

SIPs are more expensive than standard wall construction.

The maximum R value I have seen available is a 12.5 inch thick SIP that would have a thermal resistance of R46. Some manufacturers indicate that they can build any dimension but the cost of special orders may be prohibitive.

SIPs are a good option when designing your Net Zero home. Pay close attention to the costs and be sure to compare apples to apples.

having huge south windows that are specially manufactured to maximize solar heat gain
containing a large amount of thermal mass to absorb the solar heat when the sun shines
having movable solar awnings that allow 100% of the sunlight to hit the windows during the heating season and provide shade in the warmer seasons.

Windows

Note the large amount of sunlight that enters the living room of the Mill Creek Net Zero Home. Not so obvious from this picture is that they have a 3 inch thick concrete floor to absorb this heat energy. By using movable awnings, the higher summer sun does not enter the room when they do not need the heat. Moving the awnings out of the way allows the sun to shine in during the winter months when heating is required.

For more information on the MCNZH, check out their blog at www.greenedmonton.ca.