The current heatwave has prompted Propertymark, the estate and letting agents trade body, to warn that excessive indoor temperatures are becoming an issue that landlords and agents may need to address rather than simply something tenants have to endure.
The recent introduction of the Renters’ Rights Act and updated housing safety guidance mean there is an increased focus on housing hazards, which includes overheating.
Research suggests it is already affecting a significant proportion of the country’s housing stock as periods of hot weather become more frequent and intense.
According to the Resolution Foundation, around one in five homes currently experience overheating during summer conditions, while 36% have characteristics that place them at high risk of overheating in the future.
And, looking further ahead, the UK’s Climate Change Committee has warned that as many as 92% of existing homes could be vulnerable to overheating by 2050 if improvements are not made.
Why overheating matters
In England and Wales, “excess heat” is recognised as a potential housing hazard under the Housing Health and Safety Rating System (HHSRS), which local authorities use to assess risks to occupants’ health and safety.
The assessment focuses on the property itself and whether its design, condition or management creates a foreseeable risk of harm, rather than simply considering the circumstances of the current tenant.
It means even properties that perform adequately today may face increasing pressure from rising temperatures, tenant expectations and evolving regulatory standards over the coming decades.
So what are the rules?
A property becoming hot during a spell of warm weather does not automatically mean a landlord has failed in their responsibilities.
However, overheating can become a management issue where repair problems or building defects contribute to excessive indoor temperatures. Faulty ventilation systems, broken windows that cannot be opened, or other defects that prevent a property from being properly ventilated can all worsen conditions during periods of hot weather.
Landlords are responsible for maintaining rental properties regardless of weather conditions. Where tenants report issues that affect living conditions, those concerns must be investigated and repairs arranged within a reasonable timeframe.
It reinforces the importance of preventative maintenance. Addressing ventilation problems and building defects early may help avoid tenant complaints, enforcement action and potentially more costly remedial works later.
What happens if there is a problem?
Local authorities can investigate overheating following complaints from tenants, neighbours or even referrals from other agencies.
If an inspection identifies a Category 2 hazard under the HHSRS, councils can decide whether enforcement action is necessary. If a Category 1 hazard is found, they are required to act.
In many cases, issues are addressed via an Improvement Notice requiring works to be completed within a specified timeframe. More serious problems, however, can lead to emergency remedial action or other enforcement measures.
Councils can also recover costs associated with inspections, notices and enforcement activity.
Which properties are most susceptible?
There is no single cause of overheating, but certain types of property are more susceptible than others.
Older homes with poor insulation and top-floor flats beneath uninsulated roofs can be especially vulnerable. Modern homes can also face overheating issues when high insulation standards and airtight construction trap heat indoors during warmer weather.
Large south-facing or south-west-facing windows, skylights and extensive glazing can increase solar heat gain, particularly where shading is limited. Poor ventilation, faulty extraction systems and a lack of cross-ventilation can also make it difficult for heat to escape.
External noise, security concerns and restrictions on opening windows may further increase overheating risks in some developments.
What it means for BTL investors
Overheating is unlikely to influence purchasing decisions in the same way as yield, location or tenant demand do. It is, though, becoming another factor investors may need to consider when assessing long-term maintenance costs, refurbishment plans and future regulatory risks.
As global temperatures rise, investors may increasingly need to think about ventilation, solar gain, shading and cooling measures alongside more familiar considerations such as energy efficiency and building maintenance.
Properties that remain comfortable during hotter summers are also likely to be easier to let and manage.
