Flood-risk: building placement
Provided by Robert Barker: co-director of Baca Architects|
What|, Why|, When|, How|, Extras|
Building Placement is a design measure to intelligently locate buildings to minimise flood-risk to users and property. This is based on considering the use of a building and the level of the flood-risk, guidance is given in planning policy. For instance, buildings for emergency services should be placed in the area least at risk of flooding, where as a boatyard may be possible to be placed in an area which is highly likely to flood (on the basis that it is more acceptable for it to be flooded).
Though rare flooding can have a devastating effect on people’s lives and livelihoods. Badly placed buildings can also be a barrier to flood flows and displace floodwater elsewhere, putting other areas at risk. Therefore, it is essential to consider the position of a building in a flood prone area above all other site planning considerations, as it is about reducing risk to people’s lives. Well-placed buildings can limit the risk of the most vulnerable users by locating them in areas of lowest flood-risk and in conjunction with flood tolerant landscape design may help to reduce flood-risk overall.
Building placement should be considered for all sites (not just those close to a river or the sea), and particularly for large sites and new developments. When considering if a site is at risk of flooding, all forms of flooding must be considered, not just rivers and seas and changes in flood-risk based on the effects of climate change must also be considered. Ideally placement of buildings according to flood-risk should be done in conjunction with other issues such as access and landscaping to reduce flood-risk and create more sustainable development.
Key points:
-
Consider which areas of the site are most at risk of flooding.
-
Flood risk may be different across parts of the site.
-
Identify if the use proposed is likely to put peoples lives at risk if a flood occurs (at any time of the day or night).
-
Determine whether it is possible to locate the building in a different part of the site or if it would be better located on another site altogether.
-
Consider changing the use of the building to make it less susceptible to flooding.
Design procedure:
-
Step 1: Identify if the site is at risk of flooding. The Environment Agency website and the Local Authority can provide details.
|
Flood maps and flood zones. (Click image to enlarge)
|
Flood maps and flood zones. (Click image to enlarge)
-
Step 3: Establish the area of the site most susceptible to flooding and the likely depth and extents of a flood. Identify if it is possible to locate the buildings away from areas at risk of flooding.
|
Flood maps and flood zones. (Click image to enlarge)
-
Step 4: Establish whether the uses of the buildings are appropriate for the site and whether it would be necessary to relocate or change the building use, if this is not possible then you would need to introduce other design strategies such as building resistance or resilience.
|
Floodproof building types. (Click image to enlarge)
-
Step 6: Orientate the building in line with the direction of flood flows to reduce the extent of the obstacle to flood flows.
|
Buildings set back from flood-risk areas. (Click image to enlarge)
Conflicting strategies
Take this further
Case studies
There are no related case studies yet.