In Toronto, the The Tower Renewal Project is "an initiative to re-examine these buildings’ remarkable heritage, neighbourhood histories, current place in our city, and future potential in a green and equitable Toronto."
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Architects Graeme Stewart and Michael McClelland of ERA Architects are working on a faceade-retrofit strategy that adds a second skin to the existing brick filing cabinets without disturbing the tenants; it has integrated sun shading, insulation, solar hot water heating and vertical chases to bring in new services. The balconies are enclosed (but with big operable windows) to eliminate heat loss. Result: a modern, efficient building built without a gut job that displaces and disrupts everyone inside.
In Germany and other European cities they have been doing this for years; in North America, private building owners don't have huge incentives to do this, and public sector housing is barely maintained, let alone improved. When vacancy rates were low and there was real rent control, building owners loved renovating apartments because it was the only way to get increased rents; perhaps it is time to look at it again. ::Toronto Tower Renewal