A System Based Approach
Sustainability, first and foremost, can be approached through a strong focus on efficiency. That must include efficient use of energy within the completed project, but it also must consider the full life-cycle material/environmental/energetic demands of a built project. Materials require energy to produce, to transport, and to assemble. The production of materials places demands on the environment also: from the emissions they may produce, to the resources they demand. Construction consumes energy, produces emissions, and depending on the project, can have direct environmental effects through terraforming and general site preparation.Design affects more than operational (built) efficiencies; it also informs requirements of deployment. By developing a system based approach to sustainable design, our team seeks to develop a deployment-aware design strategy that is site-independent, quickly adjustable, and intuitively responsive to any and all site conditions, occupancy requirements, and material practicality.
Core design-specific sustainability and efficiency concepts:
- Tripartite materiality: low material diversity increases logistical efficiency
- Pile-based foundation: Lack of a basement reduces high-cost site preparation activities
- Passive solar veils: Strategic overhangs with fitted veils provide seasonally differentiated solar attenuation for sun-facing windows.
- Window placement: Sun-facing window placement strategies optimized for low-angle light during winter months to promote heat gain, while being well shaded during summer months.
- Simple geometric form, regularity, and scaled self-reference: allows for more efficient production, possible prefabrication, and low-cost assembly.
Site Context
As a conceptual deployment, the system will be exercised to develop a design in accordance to the parameters set forth by the competition.Our site has been situated within downtown Toronto, Canada.
Climate
Toronto is located in the far south of Canada, featuring a ``humid continental climate`` which entails dramatic temperature fluctuation between summer and winter seasons, with hot summers and cold winters.Without nearby mountain conditions, cloud-cover is not perennial, and sun is plentiful for most of the year. High humidity and hot summers creates conditions for severe weather in the summer, often manifested as severe thunderstorms. Such conditions create opportunity for active solar technologies, but also demand attention to solar heat gain through windows - which must be attenuated in the summer, but is also a valuable energy subsidy resource during winter. The roof must be able to address significant snow-loading and ice accumulation throughout the winter.
Winds tend to beaffected by the nearby Lake Ontraio relative temperature stability. In the summer, wind tends to blow towards the north from the colder lake, reversing at night as the ground temperate quickly falls. In the winter, wind tends to blow towards the south at most time as the water remains warmer than the ground.
Culture
Toronto is Canada`s largest city. Its population, especially within the downtown area, accept a fairly intense mode of living. Approximately 50% of all housing stock in Toronto is contained within highrise structures. Toronto has the second highest number of highrise buildings in North America, second to New York City. Toronto currently has the highest number of residential highrise buildings in active construction on the continent, including Mexico.The location of the site is within a locally renowned neighbourhood: Kensington Market. Kensington Market is known for its overtly urban character. Use is well mixed with a high density of small apartments and shops. A unique circumstance of the area lies in its overtly pedestrian-oriented mode. Foot traffic is high, yet public real is very limited. It is common for the narrow roads bordering the site to become informal pedestrian malls. These factors informed the space allocation and configuration of communal and public spaces within the deployment.
It is important that one considers both the typical and accepted living space/configuration in this context. The intensity and attractiveness of living within downtown Toronto has created a norm of compact living space. Even the old single family homes prevalent throughout the immediate areas feature very narrow (~1m) hallways and small living spaces in general. This article provides some background on the current residential conditions within downtown Toronto. It sites the average condo size at 749 square feet (~70 square metres).
It should be noted that, although compared to an extra-urban deployment, this restrictive site and its location in an intense environment results in what may be considered insufficient space. That conclusion misses a critical cultural understanding of urban life, especially in downtown Toronto. In lower density towns and suburbs, focus is often placed on internal space, and a complete living environment. Urban living, by contrast, adopts the paradigm of 'public living space': some living space is relocated to the public realm. The household then acts as a retreat, accommodating the more intimate and private aspects of living. The areas outlined in the following table carefully consider those context-specific conditions, and are often based on actual residences common to downtown Toronto.
The Programmatic Unit
Livability and programmatic function of the design begins the foundation of the design process. A set of guidelines assign programmatic requirements of the home and community into blocks. Each programmatic unit is assigned a specific surface area which is deployment specific, and adjustable based on personal, cultural, and contextual circumstances. Programmatic units are assigned to each resident individual, household, or community, based on the mode of use.
Site Specific Considerations
Plan Development
With the specific areas of each unit decided, units are assembled into scaled guides which inform the plan of each home.
These programmatic guides allow a focused consideration to design, spacial organization, and internal movement, and especially the alternation of opaque surfaces and glass in a way that responds to the specific solar conditions of the site and the placement of the buildings.
Deployment in Context
The three houses are arranged on the site in a sort of self-referencing form, where the central space within the home focuses actives and connections within the household, a large public courtyard connects the three houses. Responding to the pedestrian-oriented and communal cultural character of the surrounding community, the courtyard space opens towards the nearest intersection.Our sight has been placed as specifically as possible in Toronto, and therefore approximates an actual site in the Kensington Market neighbourhood. For this reason, the location of North in our project has been reconfigured to reflect the actual location of north on the selected sight of resemblance. This plays a crucial role in the solar studies undertaken to optimize the deployment.
Massing Model
A quick massing model is then constructed in digital space based on the conceptual plan organization diagrams produced.Software allows accurate solar studies in order to refine the design specifics, such as roof overhangs and the specific configuration of the passive 'solar veil' feature. 3D digital modeling
Solar Studies
Optimizing design features for limited solar heat gain in summer, and maximized heat gain in the winter.
Summer: 2 PM July
Autumn: 2 PM October
Winter: 2 PM February
Spring: 2 PM May
Design Formalization
After the basic form and performance has been finalized, formal design documentation was produced, beginning with formal plan sections. Included within this process was technical considerations such as wall construction, and structural systems. Most walls needed to be substantially thickened, and some moved according to the underlying structural logic. In all cases, it is ensured that internal space for each programatic mode is only increased.
Foundation and Structural System
In order to limit terraforming, and thus environmental site impact, most of the structure is elevated above the ground, and is without a basement. In order to acheive this, a hybrid system of poured-in-place concrete piles and a steel girder-beam grid with decking and poured-in-place slab was adopted. Some walls are grounded in the earth, and the steel superstructure carries load onto these members ("Primary Walls" below). This structural system is deployment specific, and was calculated for each of the three houses.
Construction Techtonics
The following diagram outlines the structural system as it is applied to the 6-person home, but its components are universal for the deployment system.
Also outline in this diagram are strategies for insulation. We expect to maintain around R-10 total insulation performance at all walls, and likely higher numbers under floor and in ceiling due to the larger available space between the beam and girder structure.
Approaches to Restricted Space
Space within the homes is limited. Design of the upper floor access was a considerable obstacle.
Bringing the Design to Life
With most major design challenges addressed, we were able to proceed to a full-detail model construction in digital space. This allows us to begin on fine details, such as the final design of the solar veil, materials, and construction-phase and post-construction phase sustainable systems such as:
- Grey-water recycling
- Central plant community (shared) heating systems (geothermal)
- Thermal mass boosting systems (water tubes, ceiling heat collection and recycling systems, etc.)
The Solar Veil
A veil hung from strategic, sun-facing areas of the overhanging roof line has been sized to provide full shadow from a peak summer sun over a targeted face, while permitting greater amounts of lower-angle winter sunlight. A unique proposed feature of this veil structure, specifically applied to the native climate of the project site, is the support of live vines that would populate the solar veil scaffolding.
Additional Project Renders
We have worked very hard on this design concept and continue to push it forward. We hope we have demonstrated the potential of our design system. Our philosophy is to approach design with the consideration of sustainability from the very beginning. We believe this is the true path to practical sustainable design that can be ubiquitous.We thank you for your time! Your support and feedback will be greatly appreciated!
