The two most significant risks to buildings and premises arising from expected changes to climate in the UK are likely to be:

Changes to the risk of flooding from

• Rising sea levels and increased likelihood of storm surges effecting coastal properties and low lying areas at risk of inundation if coastal flood defences fail.
• Fluvial flooding when high flow rates of watercourses cause then to overflow their normal channels (natural or engineered) causing the inundation of neighbouring low-lying land.
• Surface water flooding caused when drainage systems fail to cope with the volume of water as a result of intense rain falling onto impermeable surfaces.
• Ground water flooding caused when prolonged periods of rainfall cause the water table or aquifers to rise above ground level.

Difficulties maintaining comfortable internal temperatures in buildings due to:

• Increases in average summer temperatures
• Increased frequency and intensity of periods of extreme temperatures

There are a number of other possible impacts and risks to premises that should be considered:

Structural damage due to ground conditions and soil instability:

• Subsidence and heave due to cycles of wetting and drying of soils - likely to be particularly significant on clay soils.
• Undermining of foundations due to erosion caused by surface water runoff
• Landslips and embankment instability due to saturation and runoff from intense rainfall.
• Damage from moisture and condensation due to prolonged periods of dampness
• Structural damage due to increased frequency and intensity of high winds - there is rather greater uncertainty associated with projections of wind speeds than for some other climate variables, but a number of climate models suggest a likelihood of an increased prevalence of storms, particularly in winter.
• Increased likelihood of summer droughts

On the positive side, projected climate changes may:

• Reduce energy demands for heating
• Reduce damage from heavy snowfalls
• Reduce frost damage - models suggest a reduction in the average number of frost days which may reduce frost damage, however there may also be a risk of increased damage if occasional intense frosts freeze materials sodden by prolonged periods of winter moisture.

The risks and vulnerabilities of particular premises to these impacts will be affected by a number of factors including:

Location within the UK - climate changes are likely to be most pronounced in the south and east of the country due to proximity to the continental land mass, and rather less pronounced in the north and west due to the thermal buffering of the Atlantic Ocean.

Locational factors such as:

• Proximity to coasts or watercourses
• Land typography - valleys and low lying areas may be vulnerable to flooding; slopes subject to slip and erosion; south facing slopes are more vulnerable to heat extremes than north facing slopes
• Soil type - for instance, clay soils may be vulnerable to subsidence and heave; chalk soils vulnerable to ground water flooding and sandy soils may be vulnerable to erosion.
• Site layout including exposure and orientation of buildings
• Permeability of surfaces and effectiveness of drainage systems
• Urban heat island effects

Design and construction of buildings including:

• Age
• Type and strength of materials
• Thermal mass
• Extent and position of glazing - south facing windows are likely to produce the greatest solar gain, but may be shielded by, for instance, internal blinds, roof overhangs or external planting
• Design and maintenance of guttering and drainage systems

Function and use

• Health and comfort considerations within buildings may vary with function and types of users, for instance, young children and elderly people are likely to be particularly vulnerable to high temperatures, so schools, day centres and care homes may require particular attention to ensure they maintain safe conditions in periods of extreme temperatures.
• Premises related to the delivery of critical services need to be particularly resilient to weather and climate risks. This is particularly important for the control centre and support services for emergency responses and the capacity to deliver services to vulnerable clients.
• Although there are currently no statutory maximum temperatures for working conditions, productivity is likely to diminish with temperature extremes. This may vary between, for instance, office or manual workers.
• Machinery and office equipment may generate heat that increases the difficulty of maintaining reasonable internal temperatures. This may be particularly critical when the equipment itself is temperature critical, such of servers and other IT equipment.
• Food, artefacts and other perishable goods may require particular environmental conditions that will be difficult to maintain in a changing climate.
• Critical equipment and objects of high financial, or cultural, value should be located to minimise the risk of damage from flooding.