The cost of cleaning up after the UK's biggest storm in a decade, including repairs to buildings and road and rail infrastructure, is estimated at £1bn and rising. This follows the £1.4bn repair bill after the 1987 hurricane and the £2bn worth of damage caused by two storms in 1990.
Unsaleable, uninsurable houses
This may make it a lucrative winter for repair and maintenance firms, but Prescott has already told housebuilders and developers that he wants them to pay more towards flood defences. Under draft planning guidance PPG25, issued in April, developers will have to provide sustainable drainage systems near their developments. The new guidance will also require planners to discourage building in high flood risk areas. These restrictions come on top of March's PPG3, which prevents developers from building on greenfield land until a "sequential test" has proven that no suitable brownfield site is available.
Meanwhile, the urban white paper, to be published this month, will insist that 60% of the 3.8 million new homes required by 2016 should be on brownfield land. This leaves developers in an tricky position. As Gleeson Homes managing director Clive Wilding points out: "Most brownfield sites are former docks or industrial sites on the edges of rivers."
Now a BRE report, to be published this month by the Foundation for the Built Environment, will provide even more food for thought. The study, Potential Implications of Climate Change in the Built Environment, makes a compelling financial case for "futureproofing" buildings. It says the industry cannot afford to leave damage-limitation to governments or it will be stuck with unsaleable, uninsurable buildings. And the £1bn storm repair bill pales in comparison with the £5bn the BRE claims that it will cost to put in place the most basic of safeguards.
What the BRE report says
The report, obtained by Building, warns: "There will be significant effects on the built environment this century even if efforts to reduce the emissions for greenhouse gases are successful … changes to sea level will continue even if all industrial activity stopped now." The study quantifies the impact of climate change on buildings and suggests how building professionals can work with climate scientists to adapt building design to minimise wind damage, subsidence, damp and weather damage to materials. It also outlines maintenance regimes for existing buildings to ensure that they are robust enough to last their 60-year lives.
For example, a 6% increase in wind speed is likely to damage 1 million buildings at a cost of £1-2bn. To tackle this problem, roof fixings should be strengthened during new build or roof replacement, resulting in up to £7bn a year of extra maintenance. And when wooden window frames need replacing, these should be replaced with PVCu windows to improve ventilation and reduce damp, at an extra cost of £2.4bn a year.
Dry summers in the south of England could cause an increase in subsidence claims of £200-400m. However, the cost of futureproofing new buildings in these areas, for example by incorporating concrete raft foundations, would be only £32m. Driving rain is likely to increase up to 33% in London and the Home Counties, affecting as many as 7 million homes and leading to a higher risk of damp problems; cavity walls should be replaced with masonry in these areas.
The design of natural ventilation or passive cooling systems should be developed, says the report, to reduce the need for air-conditioning. Otherwise, hotter summers will absorb most or all of the 12-19% energy use savings that could be expected from warmer winters – and exacerbate the degree of global warming.
The construction process will have to change as well, says the report. Construction sites will be lashed by higher wind speeds and more storms. This, plus higher temperatures in summer, increased ultraviolet exposure and more rainfall, will cause new health and safety and site storage problems. One solution proposed is increased prefabrication and off-site assembly.
If this report is not enough of a wake-up call for the industry, new studies commissioned by the European Union and the UN have presented incontrovertible evidence of global warming. These will be considered by world leaders at a fortnight of talks the Hague on 13 November to broker deals on carbon trading.
Developers and contractors can no longer bury their heads in sandbags. Damage limitation must start now.
