Geography Reference
In-Depth Information
areas often provide a new source of local products, especially fresh vegetables,
herbs and flowers, and in some cases bee colonies to help the general process of fer-
tilization of trees or crops in surrounding areas. Certainly there are often additional
engineering costs in ensuring that a proper seamless membrane is used to protect
the building from water seepage, and the building structure has to be able to bear the
extra weight of the roofs, while the maintenance and gardening costs are additional
expenses, although over a ten year period the returns often outweigh the costs.
North America has seen a rapid growth in the movement, as can be seen by the
fact that only 2 million sq. feet of green roofs had been developed by 2005, but this
grew to 8 million in 2010 and more than doubled to over 16 million in 2011, with
over 500 green roof programmes on the continent, with the cities of Washington
D.C., Chicago, New York, Toronto, Nashville and Philadelphia, leaders in this trend
(LAM, Summer
2012
). Toronto even adopted a green-roof bye-law in 2009 in its
official plan, which states that new buildings over 2,000 sq m. should install a green
roof, although it seems there are ways to avoid the requirement. All of these devel-
opments have been particular useful to large hotels, where chefs can access these
various fresh products from their roofs. For example, the Fairmont Royal York hotel
in downtown Toronto developed one of the first green roof gardens in 1998 on its
14th floor and later added bee-hives. Certainly the production is still a very small
input to the overall purchasing bill, but since diners can take tours of the gardens
and see the various crops, it provides a useful reminder of the hotel's commitment
to fresh, healthy food.
Advocates of greening ideas have also begun to see other parts of buildings that
could be more effectively used to develop a green and sustainable agenda. One has
been to re-use the old Roman idea of
green atriums
in buildings, adding gardens
or trees in a ground floor area that is open to the sky, or covered with clear glass,
and surrounded by the rest of the building. Also there are increasing numbers of
interior gardens
in buildings, especially in areas with long winters. These places
are designed to provide green recreational space for the workers in the building, or
the general public, such as the Devonian Gardens on the fourth floor of a high rise
complex in downtown Calgary, which is described in the Winter City discussion
(Chap. 8).
An associated trend to the Green Roofs can be seen in the
Green Wall
movement,
which advocates the use of climbing plants to cover the outside of buildings. In
origin, the idea goes back to the historic 6 C B.C. Hanging Gardens of Babylon, al-
though with a more recent stimulus from the ivy or plant covered exteriors of many
historic European buildings. The green wall idea has recently been revived, using
plants that either grow from the ground onto the building, or increasingly on hydro-
ponic frames attached to the walls, frames that contain cells with soil, aeration and
irrigation channels. This approach means that green walls can also be developed in
indoor atriums, so long as there is sufficient light. The aesthetic advantages of the
green walls come not simply from its greenery, but from the changing colours of
some climbing plants at different seasons, providing variety to the often dominant,
yet boring, grey or brown sides of most buildings of the modernist period. Such
