Sustainable Building Guide - Christchurch City Council

Topography
On sloping sites, design the building so as to minimize earth works. Try to design to fit the
slope, this way less energy and resources will need to be expended to dig out, remove
and dump the excavated material as well as support the remaining ground. Retaining walls
are generally very expensive in both design and construction and should be avoided where
possible. Designing with the slope helps prevent the loss of soil and mature vegetation.
It also makes undermining of adjacent structures, land and trees less likely. ‘Touch the
earth lightly’ is an expression used by the award winning Australian architect Glen Murcutt
to describe his approach to the design of buildings.
Hydrology
Try to design for water storage on site so as much winter and spring rainfall as possible
can be used during summer and autumn droughts. Design for appropriate water discharge
from the site to avoid soil erosion, ponding (stagnant water for mosquitoes and other
noxious insects) and flooding. Prevent pollution of ground water by catching oil and other
chemical spills from workshops and vehicle parking areas with oil and silt traps Where
some pollution is inevitable, grade the slope to collect pollutants in a single place. This
limits contamination of a site to a smaller area that can be more easily dealt with later on
when the site is redeveloped.
Use low consumption taps and shower fittings and specify low water usage washing
machines.These same fittings will also reduce energy consumption and costs.
Recycling and Reuse of Buildings
If at all possible, reuse entire existing buildings, this will result in the least total amount of
energy being expended. This approach has the added benefits of the retention of the
existing historical context and character, and the retention of craftsmanship, detailing and
materials that may be no longer readily available (for example, native timbers or rare exotic
timbers). Try and avoid the need to demolish, remove and dispose of materials. This is
often a dangerous activity or generates potentially dangerous substances such as dust,
noise, falling materials and may disturb dangerous materials, for example, asbestos. This
activity may also result in the undermining of adjacent structures and the disturbance of
the streetscape. However, earthquake strengthening and the upgrading of fire ratings are
not achieved easily in existing buildings and particularly in older masonry structures. The
costs can be high and there are issues to be addressed such as how to retain the character
and integrity of the existing building while adding structural bracing, insulation, lighting and
other services. Advice on appropriate design and strengthening may be needed from
architects and structural engineers.
Right; Former Biscuit Factory converted to apartments and cafe, Fremantle, Western Australia.