Located in the west coast rainforest landscape of southern Vancouver Island, a twenty minute drive from downtown Victoria, the vision of the Mary Lake Parkland community is to provide a collection of 40 beautifully designed high efficiency, modestly scaled homes, arranged around a village common, with several communal facilities, including a community building which houses a bio filtration green house adjoining a communal gathering space, outdoor gathering spaces framed by a working wetland water management system, a belvedere lookout coupled with a community water tower, a car sharing facility and a well developed trail system throughout the property. The development incorporates a variety of state of the art design and green infrastructure systems, including geothermal heat pumps, a collective wood gasification boiler, supplied utilizing selective cutting forest management practices within the property, micro hydro generation providing a portion of the electrical needs for the community, and in indoor/outdoor bio-filtration waste-water management system. One-third of the 110 acre property is occupied by homes which range from fully detached to semi-detached modestly scaled dwellings between 900 and 1500 square feet, oriented to maximize passive solar and natural ventilation conditioning, based on Passivhaus principles. The remainder of the land is maintained under a land title covenant to preserve the natural beauty the park like environment, including a pristine twelve-acre lake, and its natural surroundings, for the collective benefit of all residents.
A semi-detached house type 1
Given the abundance of large trees on the site, the most common renewable energy sources like wind and solar power will be less effective than on more open sites. Instead, small-scale geothermal, micro-hydro and centralized wood gasification boiler systems were implemented as the best options for creating a highly efficient, low carbon, healthy community, that collectively uses one third of the energy and emits less than a quarter of the green house gases compared to current developments of equivalent occupancy. In conjunction with these energy systems, waste-water management is another important concern in such a pristine landscape, and living machines using bio-filtration techniques have been developed for this site, situated in direct relation with the communal spaces of the project.
The terrain of the site has its own unique characteristics, whose potential has been maximized in the planning of the community. With the use of a water tower built with a conical lattice frame Douglas Fir construction, on the highest point of the property and of natural drainage, the terrain becomes part of the water management strategy for the development. Other features of the plan include small scale, well-planned houses, car sharing, some communal facilities, and links to the green energy agenda that is central to the proposal.
Micro Hydro Power
Taking advantage of the change in elevation and the water pressure created by the flow of water in the Millstream creek, a micro hydro station was designed. The intake and turbine are placed to maximize the change in elevation (head) while minimizing the length of the pipe. This will provide the greatest energy production potential while reducing the loss due to resistance. The system on the Millstream creek can power up to 10 houses during peak flow.
The micro hydro generator has the advantage that it generates electricity in all weather and at all times of day. On a less forested site, it would pair well with solar PV panels as their periods of peak production are generally opposite.
Centralized Wood Gasification Boiler
The extensive forest on the site provides a great source of biofuel, which is both local and renewable, used to fuel a wood gasification boiler. The boiler is centrally located in the community building, with heat distributed up to 500ft from the central location. This heat source is augmented by ground source heat pumps.
Managing the woodland sustainably will ensure that the ecosystems are preserved, and the forest can continue to serve for recreational uses. The forest consists predominantly of Douglas fir with a mix of cedar in the lower lying areas and some birch, maple and arbutus trees.
Living Machine and Constructed Wetlands
The living machine treats the community’s waste water using bio- filtration methods that mimic natural wetlands. The series of ecosystems housed within the community building create a year round green space. After passing through the living machine system, the cleaned water is released into an artificial wetland where it mixes with rainwater runoff and groundwater collected on the north side of the building. The wetland provides further purification before the water is released into a bioswale to return to the lake.