Cgba2013 throughhouse

CANADIAN GREEN BUILDING AWARDS 2013

THROUGH HOUSE Toronto, Ontario

THROUGH HOUSE CANADIAN GREEN BUILDING AWARDS 2013

CANADIAN GREEN BUILDING AWARDS 2013

Executive Summary Built 128 years ago on a tiny lot in downtown Toronto, the renewal of this 135m2 single family residence is part of an overall strategy to revitalize the urban fabric instead of razing it, creating liveable environments for modern lifestyles in smaller footprints. At a residential scale, we are exploring a broader vision of urbanity one project at a time, that promotes the idea that people do not need more space, just better designed space. Nicknamed Through House, this project reworks an older home while maintaining the existing shell, using design strategies to ‘expand’ the interior space without expanding the 67 m2 footprint of the house and allowing the owners to live in a small footprint.

A constant challenge when trying to ‘sell’ our clients on sustainable systems and strategies is the high ‘first costs’ associated with these systems, despite the long term savings in reduced energy use. The main approach for this project was the incorporation of active sustainable systems integrated with as many low cost passive sustainable strategies as possible to maximize energy savings. This was achieved through the incorporation of passive cooling and natural ventilation in the summer combined with infloor radiant heating and thermal mass in the winter. Large openings and a central light well maximize daylighting and reduce the need for artificial lighting. Green space is increased with the installation of green roofs and the replacement of the paved backyard with a plant-filled oasis. This project has a walkscore rating of 98/100.

Active sustainable systems to complement passive strategies • Infloor radiant heating • High-velocity cooling • Low flow plumbing fixtures • High-efficiency lighting

Thermal Mass + Brise Soleil A brise soleil at rear of house screens large windows from the summer sun, which is further reflected off the lightcoloured flooring. Low winter sun is able to penetrate the interior, warming the cement and tile flooring through thermal mass.

Greening + Water Management • Introduction of permeable wood decking where previously paved • Introduction of hardy, local vegetation in front and back of house • Green roofs to absorb rainwater runoff, for insulating qualities and to mitigate the urban heat island effect

Materials + Finishes • FSC-certified wood lumber and flooring products • Recycled industrial felt • Low VOC paint and finishes • No-added formaldehyde wood products in millwork • Low-embodied energy fibre cement panels • 3form Varia Eco-Resin stair panels (40% pre-consumer recycled content)

Daylighting + Natural Ventilation • An operable skylight above the central shaft creates a stack effect, allowing for natural cooling and ventilation • The skylight above the open-riser stair brings natural light into the centre of the house • Large windows throughout reduce the need for artificial lighting

Maintaining Existing Footprint • Carving out of interior to create an open plan • Perceptually expand space through linearity • Maintaining of existing exterior walls and historic front facade • Introduction of high-performance insulation • Addition of durable cladding materials

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Strategic Decisions The owners of this small house had a limited construction budget but had a strong interest in incorporating as many sustainable systems and strategies into the house renovation as possible. Planning to stay for the long term, they were interested in longevity, increased comfort and long term savings due to lower energy usage. The overarching strategy was to incorporate as many passive sustainable approaches through design (natural ventilation, daylighting, thermal mass, green roofs), to complement them with more efficient essential systems (infloor radiant heating, high velocity cooling, low flow plumbing fixtures, high efficiency lighting), and to rough-in for additional systems in order to keep first costs low. Complementary to this plan, a key sustainable strategy was the decision not to increase the footprint of the house and to maintain the existing exterior walls while adding high performance insulation (there was no insulation) and durable exterior cladding materials. Specific design techniques were employed to perceptually increase the limited interior space through the arrangement of program, and strategies to extend the eye outward, visually extending the living space.

Within the interior, simple passive and active sustainable systems were incorporated for maximum impact. The design was developed around a central light and air shaft (an open-riser stair topped with an operable skylight), which, when coupled with strategically placed operable windows, creates a stack effect while drawing natural light into the centre of the house to optimize daylighting. Large windows at the rear of the house are screened by a brise soleil, allowing natural light to penetrate in the winter and warm the tile floor through thermal mass, while blocking the summer sun, also reflected off of the light-coloured flooring.

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Strategic Decisions

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Community The project preserves the integrity of the historic neighbourhood, while simultaneously renewing the urban built form for modern lifestyles. Taking into consideration the surrounding context, the historical front façade was maintained, while the interior and back are transformed, updating the house for improved energy performance. Renewal, rather than building new, significantly reduces a building’s ecological footprint and contributes to the community and streetscape. With public transportation and countless amenities nearby (Walkscore= 98/100), the owners have elected not to own a car and walk to work every day.

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Site Ecology Initially overlaid completely with concrete, the small outdoor space at the back of the house was a key component in the design and incorporation of additional living space. The pavement was removed and the backyard was enveloped with locally sourced wood, permeable to allow for rainwater to return to the soil below. Plantings are interspersed in this intimate outdoor space, including native grasses, shrubs, small trees for shade, and vines, while a new garden at the front adds green content back into the neighbourhood. Green space is maximized with the installation of green roofs, mitigating the urban heat island effect, purifying air, providing increased insulating value, and reducing storm water runoff. Rainwater collection is incorporated in a vertical cistern at the back of the house, in order to use for irrigation.

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Light and Air The open plan of this project is organized around a central, open-riser stair topped with an operable skylight, creating an incredible stack effect for natural ventilation. East facing windows on the lower level, sheltered by shrubs, bring in cool air that is circulated. The skylight is automated with a rain sensor, allowing the owners to leave it open during the day when they are at work. The stair also functions as a lightwell, drawing natural light into the centre of the house where there are no nearby windows, even though 100% of the occupied floor area is within 7 metres of an operable window. Glass and translucent materials are purposefully incorporated off of the central stair to allow light to permeate the central rooms on each level, significantly reducing the need for artificial lighting. High efficiency, low voltage lighting is used throughout, and the actual annual energy consumption of the system is 3,555 kwH per annum (26.3 kwHm2), compared to the average annual electricity consumption for a residential utility customer in Toronto of 12,000 kwH (from “The Power to Live Green: Toronto’s Sustainable Energy Strategy, October 2009”, City of Toronto, pg 16)

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Light and Air

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Light and Air

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Light and Air

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Water Conservation In the design of the landscape, rainwater collection for irrigation is incorporated in a vertical cistern at the back of the house, in order to reduce potable water consumption for plants. On the interior, low flow plumbing fixtures minimize potable water use. Domestic hot water is supplied ‘on demand’ from the radiant heating system boiler, reducing potable water wastage due to wait times for hot water. The actual potable water consumption per m2/occupant/annum for this house is 46.5 m3 or 46,5000 litres (taken from owner’s City of Toronto utility bills), compared to the average annual potable water consumption per household in Toronto at 120,000 litres per m2/occupant/annum (“Toronto Water at a Glance”, City of Toronto website www.toronto.ca/water/glance.htm and City of Toronto 2011 Census www.toronto.ca/ demographics/pdf/censusbackgrounder_hhds_2011.pdf).

Energy Present and Future The house’s mechanical and electrical systems are completely integrated with the passive design strategies to achieve the most efficient methods of heating, cooling and lighting while minimizing the cost to do so. For example, the natural ventilation and stack effect through operable windows and a central operable skylight lessen the demand on airconditioning, which is provided by a high velocity system that significantly reduces energy use compared to a standard air conditioning system. However, over the course of the past year, the owners have not had to use the air conditioning system, due to the efficiency of the natural ventilation in the house. Using the house’s orientation, large triple-glazed windows are placed strategically to allow for natural light, reducing the need for artificial lighting, and to allow for heat gain and thermal mass in the cold months. In the winter, the tiled flooring over cement base retains the heat from the low sun provided through these large windows at the rear, complementing the infloor radiant heating system. The brise soleil screens the high summer sun, which is further reflected by the light-coloured flooring. The green roofs and high performance insulation help to reduce heat loss and gain through the building envelope. Photovoltaic panels on the roof were planned but deferred due to the high cost – rough-in wiring was installed to allow for their later installation. The integration of these systems results in improved building performance, energy conservation, and occupant comfort as demonstrated by the annual energy consumption of only 7.31 MJ/m2 (taken from owner’s utility bills).

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Materials and Resources The existing exterior walls of the house are maintained and reclad in fibre cement panels, which are 100% recyclable, free from emissions of ozone-depleting products, have no VOC emissions, and have low embodied energy (the manufacturing process is not energy-intensive as grey energy= 8.3 MJ/Kilogram). They also have a long life and can potentially be removed, salvaged, and re-used in building renovations. Such consideration for durability and longevity are carried through the entire material palette, both physically and contextually, as in the case of the preserved front faรงade.

FSC-certified wood flooring was used throughout the second floor, and the fireplace is entirely clad in strips of recycled industrial felt. The stair guard panels are 3form Varia EcoResin, which are comprised of 40% pre-consumer recycled content.

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

Life Cycle Considerations Renovated for longevity and durability, this 128 year-old house has been significantly improved in order to give it a life of at least an additional 100 years, encouraging urban renewal from within. The design of the interior of the house centers on a flexible open plan defined by furniture that is easily movable, taking into consideration adaptability for future owners.

Education and Information Sharing Compared with suburban or rural areas, cities do more with less; populations living in denser habitats typically have smaller energy footprints, require less infrastructure and consume less of the world’s resources per capita. Through incorporating the existing urban fabric, this project investigates strategies to create ‘new’ dwellings for homeowners without increasing building footprints. The design process for Through House was strongly influenced by the studio’s commitment to renewing buildings, rather than razing them to the ground, while still demonstrating architectural and design excellence. This project is one of many whereby we attempt, through practice, to transform cultural attitudes about living in small footprints - by promoting the idea that people do not need more space, they need better designed space.

THROUGH HOUSE

CANADIAN GREEN BUILDING AWARDS 2013

THROUGH HOUSE Toronto, Ontario

CANADIAN GREEN BUILDING AWARDS 2013