By Neil Turner, Director, Howarth Litchfield
Well, that’s a slight exaggeration, but it certainly felt like it.
Some places in the UK have not seen any sunlight throughout January and each day has been wet receiving 150% of the longterm average rainfall (according to the Environment Agency).
In Wales, Rhondda Cyon Council, is set to buy and demolish 16 terraced houses due to severe reoccurring flood risk. You must really feel for the poor people and the stress that this causes them.
I am certainly looking forward to some brighter weather, but what impact does increasingly wet weather have on our approach to design and construction?
When we design a building and submit a planning application, the issue of flood plains and drainage strategies are now, more than ever, key elements of the planning process to demonstrate that your design, flood risk mitigation and water storage strategies can cope with the elements.
With the pressure to build on more land, particularly grey and brown field sites – (land that has previously had development) – then investigations have to make sure that the site on which you plan to build can be effectively drained and will not push water onto adjoining land.
So how do we, as architects, design in drainage? It’s no longer the sole occupation of the civil engineer, although clearly their expertise is vital. The issue of water and its storage has to be considered early in the design solutions for buildings. We cannot simply assume that the water will drain into the main water systems or water courses.
One solution is to store water on site, in storage or on the roof and then reuse it in gardens, for flushing toilets and for washing machines, potentially reducing mains water consumption by up to 40%. The options can range from a very simple water butt to complex underground water tanks with pumps and filtration.
I am involved in a project in an urban area, and we are using green and blue roof systems. There are different green roofs (intensive and extensive) but in essence a green roof is a living roof, while a blue roof provides an ability to store water on the roof.
This has to be carefully designed as nobody wants a leak inside the building. It certainly adds complexity and weight to the building as the frame has to account for the extra weight. But it prevents excess water going into the system and builds a living green roof in an urban area.
More common is the use of underground systems that store and slowly release the water to avoid flooding the mains. They also provide a large reservoir that can be used when a lack of water causes issues for gardens in the summer. So, they offer a balancing ability.
As demand increases for development, the pressure to build in known flood plains occurs, so designers have to be more innovative with how to overcome these challenges. Old buildings in known flood zones have to consider the impact for the fabric of the building and the potential safe escape of users in the building.
As we slowly move out of winter, with lighter nights, it’s worth considering maintenance. With all the water I would suggest you look at downpipes, gutters, drains and gulleys to make sure they are not blocked with debris and leaves. So much damage is done by lack of regular and simple maintenance.
Neil Turner, Director, Howarth Litchfield can be contacted on 0191 384 9470 or email n.turner@hlpuk.com
www.howarthlitchfield