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.
Typically an architectural project is divided into 4 phases: schematic design, design development, contract documents, and contract negotiation, with the occasional inclusion of pre-design services & post-occupancy review. The last post in the Tower & Court series documented the schematic design phase of these two vacation homes. This post deals with the design development phase.
Upon deciding on a schematic design to proceed with, the next step for the design team is to test their hypotheses. As we add an increasing level of detail (a comprehensive structural system, materials, etc.), and make more drawings of the building, we inevitably encounter contradictions, tensions, and conflicts within the design that we had perhaps guessed were there, but had not yet fully explored. To be sure, we also occasionally encounter unexpected synchronicities between elements, and opportunities for delight that were not fully evident at the first stage of design. One could think of the transition between schematic design and design development as a sort of focusing. As more drawings are done, the relationships between the parts become clearer.
Parry Sound Courtyard Cottage
Having selected the ‘court’ scheme for the Parry Sound property, we started to think through some different options for the roof.
These thoughts ‘in 3-dimensions’ were accompanied by thinking ‘in section’ about the different eave conditions that we could work with.
Simultaneous to this, we also continued to further define & develop the layout of the cottage. The design development stage of the project, especially at the beginning of it, is a great opportunity to explore the various different possible permutations on a basic theme. Ideally, at this point, every aspect of the design is worked over and tested.
Frog Island Tower House
Meanwhile, at the Oliphant property, design development brought with it a focus on trying out and testing various different structural systems, including SIPs (structural insulated panels), CLTs (cross laminated timber), and even concrete block.
Why concrete block, you may wonder? In bringing this project to the next level of development, we decided to face the fact that if a building is over 3 storeys tall it is required to either be constructed of non-combustible materials or be sprinklered, according to the building code. For some time we considered making the argument that CLTs (solid, thick, composite wood panels) are essentially non-combustible, as studies have shown this to be true. Unfortunately, the expense both of making this argument and of the actual panels themselves made this unfeasible. Given that this property is pretty hard to access, concrete block walls were also a bit far-fetched.
Fortunately, it was actually the height that we were looking for in this design, not the number of storeys. While the code wouldn’t allow us to go up 4 storeys, there is no rule against 3 storeys + a mezzanine, as long as the mezzanine is less than 40% of the square footage of a regular floor. We managed to easily accommodate the lost floor area in the plan by expanding the footprint of the tower slightly.
The officials at the municipality were also having some trouble with the height of the building, so to allay their fears we developed this sight diagram, to show that we would not inappropriately interfere with the privacy of the neighbours:
As with the Parry Sound cottage, we used the design development phase to do a thorough study of the different possibilities available within the basic scheme we had decided upon. Below are the plans and elevations of the cottage during this stage.