Following the news earlier this year that built environment science centre BRE was to work in partnership with flood risk management company Aquobex and architectural firm Baca to develop a design for a Flood Resilient Home, a full report has now been submitted to the Department for Environment, Food and Rural Affairs (Defra).
The aim of the project is to enable construction of new properties on land in low or residual flood risk areas, which is not currently being developed, to help overcome the current shortage of building land and BRE Construction Director, Stephen Garvin believes the design submitted could go some way to addressing the issues;
“The announcement of this project coincided with a series of severe flooding events across the UK, particularly in the south of England. These events resulted in substantial press interest in flood prevention, including a focus on flood resilient housing and businesses. It has been said that avoidance is the best way to prevent homes flooding, or else many have looked to the Netherlands and their floating and amphibious properties. For severe flood risk (greater than 1 in 75), the floating or amphibious approach, or adopting avoidance measures (e.g. through raising the building above the expected flood level) could be considered. However, for the majority of homes at flood risk, those which are at flood risk of less than 1 in 75, but greater than 1 in 1000, resilience is the best solution, and as such it is this approach that the project team has chosen to remain with for the FRP design.”
The design approach used in the Flood Resilient Property (FRP) design is innovative and uses the principles of resistance and resilience of the property, but it sets out how to deliver such an approach to the mass market house building sector and the low rise non-domestic market.
As the flood depth increases above 600mm, water is allowed to enter the property at a designed safe flow rate through windows and doors. For the windows sensors will be linked to automatic opening devices that will open when the flood depth reaches 600 mm. The flood doors will have built in devices related to the inundation depth. The controlled inundation of the property avoids the risk of structural collapse through pressure being applied on the walls.
The controlled inundation is linked to a resilient indoor design and construction. Internally, material choices and design decisions mean that little or no damage will be done to fittings, furniture, services and appliances. Post-flood, once the water has receded, the recovery period will be brief, simply requiring the internal finishings to be quickly dried, cleaned and sanitised. No ‘stripping out’ of materials will be required, and full habitation can be achieved much more quickly as services can be simply switched back on.
New innovative materials and products, or existing products used in a new way, are incorporated into the design to ensure this occurs, such as closed-cell cavity wall insulation and automatic shut off valves on water and electric services, linked to flood alarm systems. In addition, measures will be provided so that a family living in an FRP have all emergency provisions at hand, including dedicated storage space for a flood kit and ground floor escape windows for safe evacuation.
The innovative FRP design has the potential to address the insurability of buildings. The target area of risk does not concern the highest level (i.e. greater than 1 in 75), but does address less than 1 in 75 to 1 in 1000, where a substantial number of properties are being built. As the insurance market adapts to Flood Re from 2015, the FRP approach will be important to address new development, especially in the absence of any meaningful standards or regulations in this area.
Dr Garvin adds;
“This project represents a major step forward in the area of flood resilience. The project has developed a detailed climate resilient design for low-rise properties that is designed to cope with the type of flooding that accounts for over 95% of flood events. The overall aim of the project was to produce a property design for the construction of low rise housing, commercial property and industrial units in flood risk areas. The design is intended to show through a demonstration building at the BRE Innovation Park, Watford, that new buildings can withstand the worst effects of flooding. The demonstration design will be open source, allowing designers, developers, contractors and clients to readily adopt flood resilience within their work in flood risk areas.”
Addressing issues around built environment resilience through investing in research, innovation and new knowledge generation, BRE’s Centre for Resilience supports improved standards, certification of resilience measures and support good practice demonstrations of resilience technologies. BRE Centre for Resilience is proud to be supporting RESILIENCE14, the free-to-attend exhibition and seminar programme dedicated to the technologies developed to protect the built environment from flooding, storms and extreme temperatures which takes place in Watford on 26 November. For further information on the event, log onto http://www.resilience14.com