Key takeaways
- UK law requires a "reasonable" indoor temperature, not a fixed number. Guidance points to at least 16°C for mostly sedentary work, or 13°C for rigorous physical work.
- There's no legal maximum temperature, though that's under review. In June 2026 the government committed to reviewing the guidance through the Health and Safety Executive (HSE), following pressure from the TUC and the Climate Change Committee for a statutory limit.
- Employers must carry out a risk assessment, consult staff, and give extra protection to pregnant and breastfeeding employees.
- Employees can only lawfully refuse to work over temperature in narrow circumstances, where conditions amount to "serious and imminent danger", not simple discomfort.
- Good office design (ventilation, zoning, glazing and layout) does more to solve temperature problems day to day than any legal minimum ever will.
This scope covers England, Scotland and Wales, where the Health and Safety Executive (HSE) sets the rules. Northern Ireland has its own regulator, HSENI, and isn't covered here.
Summary
- UK office temperature regulations
- No legal maximum
- Employer duties: risk assessment
- Practical steps to manage temperature in offices
- Employee rights and how complaints are handled
- Proposed heat regulations in 2026
- How office design supports comfort during heat waves
- Getting your layout to work with the rules, not against them
UK office temperature regulations
Every business asking about office temperature runs into the same starting point: what does the law actually say?
The core rule sits in the Workplace (Health, Safety and Welfare) Regulations 1992. It requires employers to maintain "a reasonable" indoor temperature. Reasonable is not a number. It's a standard, judged against the work being done and the conditions in the building.
Behind that sits a wider duty. The Health and Safety at Work etc Act 1974 requires employers to protect staff health and safety "so far as is reasonably practicable", covering temperature as one part of a much broader responsibility.
The legal minimum temperature for offices
The HSE's Approved Code of Practice gives a working figure most guidance and dispute resolution refers back to: at least 16°C where work is mostly sedentary, or 13°C where the work involves rigorous physical effort.
This is only guidance, not a binding legal minimum. In practice, though, regulators, employers and employment tribunals treat this figure as the benchmark.
No legal maximum
This surprises most people who look into it. There is no legal maximum temperature for a UK workplace.
The HSE's own reasoning is that heat in a workplace often comes from the work itself (machinery, equipment, occupancy, physical activity) rather than the weather alone, so a single fixed ceiling doesn't work sensibly across every type of workplace. Instead, "reasonable" is assessed case by case, against the specific work and environment.
Employer duties: risk assessment
Employers carry real, ongoing obligations here, not just a duty to react when someone complains.
Under the Management of Health and Safety at Work Regulations 1999, employers must assess temperature-related risks and put controls in place. That includes consulting staff, or their representatives, on how best to manage high or low temperatures, not just deciding unilaterally.
There's a specific extra duty too: risk assessments must cover pregnant and breastfeeding employees, and if a temperature risk to them can't otherwise be removed, the employer must suspend them on full pay.
Practical steps to manage temperature in offices
Once the legal picture is clear, most businesses want to know what to actually do about it.
Immediate measures cover the obvious ground:
- Fans, portable heaters or air conditioning
- a relaxed dress code during a heatwave
- more frequent breaks
- easy access to water
Structural measures go further. This could mean adjusting work schedules around the hottest or coldest parts of the day, or enabling remote or hybrid work during extremes rather than pushing through in an uncomfortable office.
Keep a written record of your risk assessments and the actions you took, and review your approach after each hot or cold spell rather than only when a new one starts.
Employee rights and how complaints are handled
Employees have a clear first step: raise it directly with the employer. Most temperature disputes are resolved at this stage, long before anything more formal.
A right to refuse work does exist, but it's narrow. It applies where conditions amount to "serious and imminent danger", not simple discomfort. Feeling too hot or too cold isn't, on its own, enough to justify refusing to work.
Employees are protected from unfair or constructive dismissal for raising a genuine temperature concern, which matters for how employers should handle a complaint once it's made.
Proposed heat regulations in 2026
This is the part of the picture that's changing, and it's worth knowing about even though nothing has passed into law yet.
The TUC has called for action once temperatures pass 24°C, and a right for staff to refuse work above 30°C, or 27°C for physically demanding roles. Separately, the Climate Change Committee has recommended a statutory maximum temperature be written into law, rather than left to guidance.
The government's own position, as of June 2026, is that it has committed to reviewing the Approved Code of Practice through the HSE, with a public consultation expected. Nothing here changes the current law yet, but it's the clearest signal in years that a legal maximum could eventually exist.
How office design supports comfort during heat waves
The law sets the rules, but good design is what actually keeps people comfortable day to day.
Ventilation and airflow need to be balanced carefully. Employers have a duty to supply fresh air, but more ventilation in winter can pull heat out of a room, so the two need managing together rather than treated as separate problems.
Zoned heating, ventilation and air conditioning (HVAC) should be designed around your actual layout. This lets different areas run at different temperatures, so those working in a meeting room can have more cooling than those at the desks, for example.
Glazing, shading and solar gain (heat that builds up from sunlight through windows) are design choices that reduce overheating before you ever need mechanical cooling to fix it.
And because comfortable temperature genuinely varies from person to person, hot-desking and a flexible layout give people a practical way to find a spot that suits them, rather than everyone fighting over the same thermostat.
Getting your layout to work with the rules, not against them
UK law leaves employers with a duty to be reasonable, a risk assessment to carry out, and, from 2026 onward, a genuine possibility of tighter rules on the horizon. None of that tells you how to actually keep an office comfortable through a British summer or a cold snap in January.
That's where design earns its keep. Ventilation, zoning, glazing and a layout that gives people some choice do more for day-to-day comfort than any legal minimum, and they're also what makes a risk assessment easy to act on rather than just easy to write.
See also our guides to Top 8 Office Design Requirements and Ventilation in Offices for more on how we think about comfort as part of a wider fit-out.
Frequently asked questions
What temperature can I refuse to work in?
There's no specific number that lets you refuse to work. The right only applies where conditions amount to "serious and imminent danger", which is a high bar, well above ordinary discomfort.
What is the legal temperature for an office?
There's no single legal figure. The law requires a "reasonable" temperature, and HSE guidance points to at least 16°C for sedentary work, or 13°C for physically demanding work, as the benchmark most commonly used.
What are the HSE guidelines for office temperature?
The HSE's Approved Code of Practice recommends a minimum of 16°C for mostly sedentary work, or 13°C where the work is physically demanding. There's no equivalent maximum figure in current guidance, though this is under government review.
What is an unsafe temperature for an office?
There's no fixed threshold in law. An unsafe temperature is judged against the specific work and environment, and against whether the employer has properly assessed and managed the risk, rather than against a single number.
