Housing: How to avoid overheating

  • UK summer temperatures could rise by up to 4˚C by 2050, experts predict
  • Rising temperatures caused by climate change could lead to an increased risk of overheating in social housing, potentially putting tenants’ lives in danger
  • We discuss how you can reduce the risk of overheating in your properties

The record-breaking heatwave of 2003 saw a sustained period of high temperatures not seen in Europe for 500 years, with around 2,000 deaths linked to the heat.

Within a generation, experts believe the temperatures seen that summer could become the norm. In fact, it is predicted that by 2050, average maximum summer temperatures in the UK could increase by up to 4˚C.

One of the effects of rising temperatures that is of most concern to Registered Providers (RPs) of social housing is the increased risk of overheating in homes.

Demographic changes mean RPs are likely to be responsible for housing increasing numbers of elderly tenants, who will be particularly vulnerable to the effects of extreme heat.

These and other house-bound groups (such as those suffering from illness or young children) are also most likely to be inside their homes during the middle of the day, when the heat is at its most intense.

Overheating: what’s the cause?

Climate change may be partly to blame, but the problem of overheating is often compounded by the way that modern properties are designed and built.

There is growing evidence that overheating can be a greater problem in newer homes that are built to satisfy more demanding energy efficiency standards, as developers sometimes struggle to strike the right balance between ensuring a property is well-insulated and well-ventilated.

Common design features that can lead to overheating include:

  • Poor ventilation, e.g. windows that cannot be opened wide enough
  • Inadequate/incorrect insulation of heating pipes in apartment blocks
  • Overuse of lightweight construction materials
  • Insulation materials blocking ventilation
  • Landscaping – a lot of hard surfaces outside a property, such as car parking spaces, or pathways, can lead to warmer air, as less heat is absorbed into the ground. This reduces the cooling effect of opening windows and other ventilation sources
  • Urban “heat islands” – dark tarmac and brickwork from neighbouring buildings can release heat at night, preventing homes from cooling properly.

How overheating can be combated

To ensure your tenants are protected against the effects of extreme heat, it is first necessary to understand what vulnerabilities exist in your housing stock.

One recent survey found more than a third (36%) of UK housing providers do not have a process to assess the risk of overheating.

You should ensure your organisation has a formal mechanism to assess the risk of overheating in new and existing properties.

To improve efficiency, you should also ensure that measures to combat overheating are factored in at the design/refurbishment stage, rather than inserted on an ad hoc basis later.

Practical measures you can take could include:

  • Using light-coloured paint or cladding on external building surfaces, and lighter-coloured materials for nearby paving and car parking spaces
  • Turning roofs into ‘cool roofs’. This can be done by either: using cooling materials; applying a solar-reflective coating to the roof surface; or covering a roof with vegetation to reduce the flow of heat into a building
  • Making the most of water features, including ponds and fountains
  • Glazed areas are the biggest cause of excessive solar heat gain and unwanted glare in homes. Use of blinds or awnings can greatly reduce interior room temperatures. When completely closed and lowered on a sunny window, internal blinds can reduce heat gain by around 45%
  • Planting trees and shrubs to increase shade and using lawn instead of paving where possible.

Ventilation is also a vital consideration. As part of your regular maintenance, you should ensure all windows can be opened and closed easily and safely.

Ground-floor tenants may be reluctant to leave windows open at night for security reasons. However, there are options for secure ventilation, such as windows with restricted opening, or those fitted with secure grilles or small air vents.

Communication is key

Your tenants may not always be aware of the potentially damaging effects of overheating on their health.

You should use your communication channels to spread important safety messages, particularly during the summer months and in advance of any predicted heat waves. Age UK offers some simple, practical tips for staying cool.