A rainwater harvesting system is featured in this case as part of a plan to capture and re-use rainwater in toilets and washing areas. The excavation was prepared by our company, in anticipation of the large underground tank to be installed beneath the front yard. This consideration could help with overloaded city storm sewers in a drastic way if implemented consistently on a large scale.

Sustainable materials are in part those which can be replenished by nature over a reasonable amount of time. This makes most types of native timber an excellent choice for building. The soffits of this project, both front and rear were made of cedar and installed by Wilkinson Construction. Cedar is naturally resistant to insect damage and rot, not to mention it’s visual beauty after installation.

A project of this nature also requires some of the same considerations as that of a conventional home.

Our ability to bend aluminum on-site to custom fit was needed in multiple areas of this home. Window flashings needed to be constructed to architect’s specifications to cap each window off from the elements. Base flashing was also needed around the perimeter of the entire home, as well as all exterior decks. Different colored stock was used as needed.

Grey steel capping visible on the top surface of walls and railings was fabricated off-site by our company as well. Steel is a better choice in these areas due to width needed and for durability reasons.

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Carbon and Construction Material

Carbon is emitted in different ways due to construction. Some ways are direct, such as the lifespan of a building. Material wasted is carbon emitted with no benefits at all. If cheap, low quality construction methods are employed, the minimum to pass inspections the building can’t be expected to have a long, maintenance free lifespan. This leads to more costs, more materials and most likely replacement and disposal of many components along the way. In the big picture this building has been built twice over, at twice the cost and twice the use of material. A better use of all this time, money and material would have been to build a high quality lasting structure to begin with. This not only increases efficiency, but in turn also increased the value of the building.

An example of indirect carbon intensive construction, includes materials that require high levels of energy output to get them to a usable form. Remember, that one of the greatest carbon emitting sources on the face of the earth is fossil fuel. When you consider the amount of fuel being burned over a relatively short period of history, this is really no shocking news. Plastics and chemical based materials are good examples of material that uses and includes petroleum in their making.

The bottom line is, materials that are renewable and available such as wood, glass, stone and recycled material should be utilized. Concrete is another good material to choose when building. Although it also required large amounts of energy to make, its ingredients are renewable and well-built concrete structures can have a life expectancy of much more than one hundred years. The use of concrete is much more of an issue that it’s making. When large concrete structure go up, then the property changes hands and the same structures are torn down inside of ten or even five years, that is carbon intensive.

Fuel Related Carbon

More obvious emissions come from the day to day operations of the home. Electricity that the home consumes comes largely from coal burning generation stations. The reason, this is currently cheap, money wise. Cleaner sources of power such as solar, wind and water can reduce emissions caused by the home if they are used in generation facilities. However currently they don’t make up a very large percentage at all. The fuel a home burns directly, is evidently one of it’s largest contributors to carbon emissions. Especially in Canada’s climate, the largest use of dirty energy is home water heating and space heating. Currently cost effective, this can not last forever. The law of supply and demand dictates what will inevitably happen. Our population is on the rise and our supply will begin to run out. The end of our oil reserves shouldn’t be the concern, it’s the point that production begins to decrease and demand continues to increase. This difference will increase exponentially, most likely resulting in suddenly very, very expensive oil.

Possible solutions

There are lots of options that can be implemented in residential construction today that are not “new” ideas. They may be relatively new to us, but they have been used here for some time, as well as more widespread use in Europe.

Heating and cooling are very important here in Canada due to the wide range of temperatures in the annual cycle. Basic ideas like sunshades and sun porches, with interior doors closed, can shield the home from intense heat in summer. Open areas that let warm air naturally rise to open windows near the top of the home can create a cooling “chimney” effect inside. In winter, the windows allow solar heat gain into the house and the sun porch is a great heat collector. Other options for low carbon heat are solar and wood.

Wood is considered a carbon neutral fuel, as it absorbs carbon during it’s growing years and releases carbon when it burns. Wood still releases the same amount of carbon if it is allowed to rot, so it makes a good fuel option.

Wood pellets are now receiving increased attention as a viable fuel. They allow waste wood chips, sawdust and other scrap to be converted into a usable fuel. Some of the benefits include low ash production and more consistent low labor heat. The drawbacks are for the most part lack of awareness. Where to get wood pellets and equipment? Where to get service for your equipment? There is still the fact that ash is produced and needs to be physically removed every couple of weeks. Whether it burns in log form, or in pellet form, wood is a good bet!

Solar heat is best utilized when it is combined with hot water. Solar units are available for residential use. These units use ultraviolet light to heat a liquid, which transfers the heat to the hot water units in the house. This allows heat to be generated even on the cloudiest of days. Hot water, or radiant heat can be distributed throughout the home by way of in-floor heating, radiators or forced air with heat exchanger.

In my opinion, a theoretically great system would be a solar assisted, wood pellet boiler setup. The solar hot water provided could be used for space heating and domestic use. The boiler could provide any additional heat required. This would also further improve wood pellet fuel use efficiency.

In order for these types of heating and cooling methods to be effective, we have the rethink one very important thing, insulation and placement of the insulation. Regular stud walls, insulated to R-20 should be a thing of the past. Super-insulated walls that are slow to gain or loose heat will help keep the temperature were we want it. Part of this idea is also creating thermal mass within the structure.

An ideal thermally massive super-insulated wall would be built in this way. A concrete or brick superstructure is perfect for this application and lots of it. Outside this, the insulation is fastened to the external side of the structure, then the siding veneer is added. The concrete structure is insulated from the changing temperature on the outside of the building. The actual concrete wall becomes the same temperature as the indoors. Because of the insulation and the fact that concrete takes such a long time to change temperature, much less heat is lost through the walls. This concept also isolates the wall material. With a stud wall the outside of the stud is cold and the inside is warm, this results in thermal transfer, a building just gives up heat because of the direction of the framing members!

These are just a few good ideas that we can consider when thinking ahead to the future of construction, trying to lower carbon emissions and making better use of resources. Although this seems to make sense, there is plenty of resistance and people with reasons why it won’t work.

The main reason is of course, money. If it cost’s more we are naturally adverse to the idea. Also, the fact that it is a different idea than what we’ve been practicing makes it a hard sell. Sometimes it’s the actual idea of change that seems to be the big hold up. Our current system seems to be working fine at first glance, so why would we change it unless we have to? Well, soon it may no longer be a choice. Why not take the time and plan ahead? It usually pays off.