The City of Kamloops, located in the central interior of British Columbia, Canada receives an average of 2074 hours of bright sunshine per year according to Environment Canada, making it the ideal location for the construction of sustainable housing that is powered by the sun.
The Sun Rivers development features many advantages that make building sustainable housing more feasible. This clustered development is arranged along a south facing slope, offering excellent access to sunshine and views for all residents. Located across the South Thompson river from downtown Kamloops, Sun Rivers is known for several development innovation: it has accomplished a joint cooperative effort with the Tk'emlups (Kamloops) Indian Band to offer long-term single lot leases; and it has overcome the prohibitive cost of ground source geothermal installation by partnering with a single utility company (Corix Utilities) to install and maintain all utilities. Future phases of the development will introduce more commercial space for retail and services.
The site itself at 1858 Ironwood Terrace is an end lot with unobstructed access to the sun, with the exception of a future house to be built to the northwest. This demonstration house will be centrally located within the Sun Rivers development so that it can positively influence the way the surrounding housing will be built. The "Ironwood" neighbourhood features English Country style homes that appeal to a broad range of homebuyers.
The concept for The Green Dream Home is a simple one: reduce electrical demand through the use of efficient systems and effective envelope design, then produce the remaining energy required using grid-tied photovoltaic cells. This practical, comfortable, and affordable home will be designed to fit comfortably into the neighbourhood. As such, we intend to show that the time for EQuilibrium housing has arrived. By featuring the five key principles of EQuilibrium housing, this house will become a model for sustainable deign and construction.
Coming together to produce this building is a team made up of construction industry professionals organized by the Canadian Home Builders' Association Central Interior (CHBA CI), educators and students from Thompson Rivers University (TRU), design professionals, construction material suppliers and installers, a private utility provider (Corix Utilities), and the Tk'emlups (Kamloops) Indian Band. This unique group of interests will ensure firstly that the finished product will be completed successfully and will be of the highest quality, but more importantly this group will ensure that what is learned from this project will be shared with everyone in the industry.
Each year the CHBA CI sponsors the construction of a "training house" on land that is purchased from a developer at a reduced rate. The majority of the home is built by trades students enrolled at TRU under the supervision of skilled instructors. This training house is then sold to the Kamloops YMCA/YWCA at a greatly reduced rate and then raffled off as a fund raiser. This is a win-win situation for everyone, as the students gain valuable hands on experience, the CHBA CI promotes itself through community involvement, and the "Y" generates funds that are used for programs supporting children and youth, summer camps, and facility upgrades.
In the past two years the training house has been a Built Green and Power Smart Gold and Platinum level home, but this year it was decided that the project should be a net-zero energy home. With the assistance of the Canada Mortgage and Housing Corporation (CMHC) EQuilibrium Sustainable Demonstration Initiative this yearly project could evolve into one that showcases the latest innovations in sustainable design and construction.
Insulated 18 3/4" concrete forms (ICF) will be used to construct the foundation and exterior walls of the project. ICF walls have the following advantages over framed walls:
In addition to ICF walls, the Green Dream Home will feature:
As detailed in the previous section, a super insulated and well sealed envelope will be provided which will decease the heating and cooling load of the building. Efficient systems will then be employed to provide space heating and cooling, lighting, and hot water heating for the home. Increasing the energy efficiency of the house will reduce the number of solar panels required for the project, reducing the overall construction cost of the project.
While natural gas is suppied to the building site, there is no intention of connecting the home to this supply. By keeping with an all electric system, it will be simple to monitor the energy usage in the home and to demonstrate that net-zero energy usage is possible.
As is common throughout the Sun Rivers development, heating and cooling will be accomplished using a high efficiency heat pump connected to a ground source geothermal well. Exhaust air and supply air will be mixed using a heat exchanger to further increase the efficiency of the HVAC system. The geothermal system will also be used to preheat the hot water for the home. Combining the geothermal system with effective passive solar design, a solar hot water heating system and additional water strorage capacity will create a system that is much more efficient than each part would be on its own. LED and fluorescent lighting will be used throughout the project in combination with passive daylighting techniques to drastically reduce the electrical requirement for lighting the house, as will the installation of energy efficient appliances.
The 12/12 pitched sloping roof on the South side of the house, which has been designed to shade the facade in summer and allow light into the interior in the winter, has been extended downward to create over 100 square meters for the placement of 36 photovoltaic panels and a solar hot water heating system. While this is more area than is currently needed to balance the energy usage of the home, this design provides room for expansion - not just of the physical footprint of the building, but for the energy generating capacity as well. The home will be kept to a minimal size relative to other homes in the development, further reducing the space heating and cooling requirements, but the design allows for expansion in the event that the homeowners require more space at a later date.
A grid tied photovoltaic system will be installed as the sole source of renewable electrical energy for the project. This system allows the homeowner to sell excess power to the utility company and buy power when needed eliminating the need for the homowner to deal with batteries, and increasing the reliability of the system. Back up batteries may be installed to allow the homeowner to ride out short power outages.
The use of a high efficiency ground source heat pump is ideal for a forced air HVAC system. The air will be filtered using a HEPA type filtration system and the air will be conditioned to temperature and humidity levels governed by ASHRAE standard 55. While passive heating and ventilation strategies are being employed in the project, it is important to ensure that adequate levels of ventilation are being supplied to all rooms even when heating and cooling are not required, therefore a fully ducted mechanical ventilation system will be required. An economiser function may be specified for the HVAC system that will bring in air directly from the exterior when conditions are suitable, for example at night in the summer when the outside air is cooler than the interior environment. This will further reduce energy demands.
It is important as well for individuals to have control over their immediate environment. Therefore, this project will offer in each room the ability for the occupants(s) to adjust the HVAC and lighting levels, or to open a window for fresh air. Ducting should be sized to allow for low velocity air delivery, which is more efficent and less disturbing to occupants. The super insulate walls will exhibit excellent acoustical properties, and the extra thermal mass will help to moderate any fluctuations in temperature. High quality potable water will be delivered to the site from a water tereatment facility located nearby.
Careful attention will also be paid to the specification and installation of materials that emit no (or low levels of) harmful chemicals into the indoor environment. Hard surface flooring will be installed for ease of cleaning. No fuel burning appliances will be used in the project and careful attention will be paid to sealing out soil gases.
A cradle-to-grave approach to construction will be undertaken with this project, giving careful consideration to the source of materials and their eventual reuse in the event that the building is demolished. Resued or recycled products will be given priority over new materials. Both the design and materials selection will be carried out with durability in mind. Rapidly renewable mateials will be considered, especially for interior finishes that are typically less durable. Wherever possible, materials will be used in their natural state, toxic glues and coatings will be avoided and no CFCs or HCFCs will be used.
Many sustainable construction materials are redily available in and around Kamloops. There is a cement manufacturing plant within a ten minute drive of the site. While the monutain pine beetle infestation continues to devastate the pine forests in the areas there is a much greater supply of pine lumber than can be used by industry. The pine lumber is suitable for framing, but the blue stained wood is also aesthetically pleasing and will be used wherever possible as a finishing material within the home. For example, the pine flooring that will be used on the second floor is less expensive than most laminate flooring but lasts longer, uses fewer chemicals and can be recycled or reclaimed. The structural framing members and wood flooring will be supplied by local mills (within 100km) from third party certified sustainable forests.
The Sun Rivers development features separate metered services for potable and irrigation water, where the residents pay for their water according to usage. Irrigation water is untreated, reducing the amount of treated water that is delivered to the site, greatly reducing the impact on the environment. Rainwater from the roof will be collected in cisterns for irrigation, low flow fixtures will be installed, and a gray water recycling system will be considered. Any site runoff will be collected in a retention pond for the development and slowly dissipated.
The project is close to parks, rivers, golf courses, skiing, and various other places for outdoor actvities that will encrourage the occupants to come out of their home and engage with the environment, increasing awareness of the effects that their actions have on the environment.
The house itself is designed to minimum requirements of the development guidelines, but through the use of the CMHC FlexHousing approach it will be possible for the owner to increase the occupied space with either an addition onto the east side of the house, or with conversion of the basement into an in-law-suite. Both levels of the home are directly accessible from the exterior, and the home will be designed so that it is easily adaptable for persons with a greater need for accessibility. By designing the home using modular dimensions, construction waste will be minimised. A waste and energy conscious approach will be implemented during construction. Value engineering techniques employed throughout the design and construction phases will aim to eliminate unnecessary materials.
Landscaping for the project, is to be designed by the TRU horticultural students, and will incorporate a combination of drought resistant decorative planting with edible landscaping aimed at reducing the ecological footprint of the occupants. Trees will be carefully placed to avoid shading the PV panels while providing desireable shade to the east side of the house.
Throughout design and construction this project will be used to demonstrate sustainable initiatives to students as well as the general public. in the six months after construction it is expected that this building will draw record crowds of an estimated 60,000 visitors compared to previous training houses due to its unique status as a net-zero energy house.
Other than the extremely sustainable nature of this project, which requires a more integrated design process and more intensive monitoring during and after construction, the proecess will be much the same for this training house as it has been in the past. The process will however take longer than usual to complete and showcase as required by CMHC. While recent designs have been completed by private design firms, this house will be designed by a team made up largely of Thompson Rivers University instructors and students. As always the TRU trades students with help from their instructors and supported by Canadian Home Builders' Association Central Interior member contractors, sub trades and suppliers will build the home, which typically takes eight months. Due to the involvement of many industry experts the quality of construction seen in the training house is better than that seen in typical residential homes. The project is financed by the CHBA CI and then sold to the YMCA/YWCA. The sale cost is low because most ofthe basic labour is donated, but careful attention to construction costs is important for the "Y" to maximise their funding. If the home is seen as a good value, more tickets should be sold. There is typically a three month time frame when the raffle tickets are being sold by the "Y" so the public can view the home, but this will be extended to six months (June - November 2010) for public viewing.
To facilitate the promotion, education and informational aspects of the home, a professional Marketing Strategy has been prepared, approved by CMHC. The plan incorporates, the usual printed materials and advertising processes, but also includes the production of a film from the on site time laspe cameras that take pictures every 15 seconds. The individual pictures from the two cameras are storage for future access in the production of this film and provides a continues record of the home's construction. Additionally a film production company is to be retained to produce a documentary 15 - 20 minute film on the "green" highlights of the home for distribution nationally through the media, CMHC, CHBA and educational institutions to be used as a educational instruction tool.
