Landlords may need to give overheating risk more attention as hotter summers, converted commercial buildings and older housing stock combine to make indoor temperatures a more practical property-management issue.
Property Industry Eye reports that Zurich UK has warned about overheating in office-to-residential conversions after analysing government planning data. According to the insurer, applications to convert offices into residential properties in England rose from 1,025 in 2022 to 1,623 in 2025, a 58% increase.
The warning is timely because parts of the UK have been dealing with heatwave conditions and because many homes were designed mainly around retaining heat in colder months. For landlords, the issue is not just whether a home feels uncomfortable for a few days. It touches property standards, tenant complaints, maintenance planning, building fabric, ventilation and the suitability of homes as the climate changes.
Why overheating is becoming a landlord issue
Zurich’s concern is that some commercial buildings were not designed for people to live in around the clock. Large areas of glazing, limited shading, poor ventilation, dated building fabric and the urban heat island effect can all make converted homes harder to keep at reasonable temperatures during prolonged hot weather.
That matters for landlords who already own converted flats, are considering buying one, or manage homes in dense urban areas. A building that works as an office during business hours may perform differently when it becomes a full-time home, particularly if residents have limited control over ventilation or solar gain.
The issue also goes wider than conversions. Property Industry Eye separately highlighted practical measures being discussed for hot homes during the current heatwave, including shading, careful ventilation, reducing internal heat sources and using fans appropriately. Those points are not a substitute for proper assessment, but they show how quickly overheating can become part of the day-to-day tenant experience.
Here4 Landlords has previously covered wider housing hazards and warning signs landlords should not miss. Overheating sits in that same practical family: it is a condition issue that can become harder to manage if it is treated as a one-off weather complaint rather than a property-performance question.
What landlords can review
A sensible first step is to identify homes that are more likely to overheat. Top-floor flats, homes with large south- or west-facing windows, converted commercial premises, poorly ventilated studios, homes above heat-retaining hard surfaces and properties with limited shading may deserve closer attention during summer inspections and tenant check-ins.
Landlords can also review whether tenants have practical control over the basics. That includes safe and usable windows, working extractor fans, clear instructions for any mechanical ventilation, effective blinds or curtains where supplied, and prompt repair of defects that make rooms harder to ventilate. Where communal systems are involved, managing agents or freeholders may need to be part of the conversation.
Records matter. If a tenant reports that a room becomes excessively hot, record the complaint, the date, the weather context, the inspection findings and any action taken. The point is not to promise that every home can remain cool in a heatwave. It is to show that genuine condition concerns are being considered properly and followed up where reasonable.
For landlords planning refurbishment or purchase decisions, overheating risk can be folded into the same due diligence as damp, mould, insulation, glazing and ventilation. The cheapest short-term option may not be the best long-term fit if a home is likely to become harder to occupy comfortably during hotter summers.
Converted homes need particular care
Office-to-residential conversions can be valuable additions to housing supply, but they are not all the same. Landlords looking at converted units should ask how the building deals with solar gain, fresh air, extract ventilation and night-time cooling. They should also understand what is controlled inside the flat and what depends on a block manager, freeholder or building-wide system.
Where a conversion is newer, check what overheating assessment was carried out at design stage and what assumptions were made about window opening, shading and occupancy. Where a conversion is older, or where a property has been altered over time, a building surveyor or appropriately qualified professional may be needed to assess whether practical improvements are possible.
This is especially relevant where a landlord receives repeated complaints from the same home or the same block. Repeated overheating reports can point to a property-specific issue rather than simply unusual weather.
Keep the response practical and proportionate
Landlords should avoid making improvised promises or treating overheating as a matter of tenant preference only. A better approach is to inspect, document, separate behavioural tips from property defects, and take professional advice where a building may have a design or ventilation problem.
The same housekeeping discipline used for other standards issues is useful here. Keep maintenance records, note inspection findings, confirm what has been repaired, and retain communications with tenants, agents and block managers. Our recent piece on the refreshed HHSRS landlord and agent guide is a useful reminder that health and safety concerns are best handled through evidence and follow-up rather than assumptions.
The practical takeaway is simple: overheating is moving from an occasional summer nuisance to a property-resilience issue. Landlords do not need to overreact, but they should know which homes are most exposed, keep ventilation and shading arrangements under review, and treat repeated heat complaints as something worth recording and checking properly.
