You have probably heard about outdoor air quality — pollution levels, clean air zones, diesel emissions. But the air inside your home or workplace is likely to be significantly more polluted than the air outside. Research consistently shows that indoor air is on average 3.5 times more polluted than outdoor air. And in the UK, we spend around 90 percent of our time indoors.
The UK government is moving to regulate indoor air quality for the first time. This article explains what indoor air quality actually means, why it matters for your health, what is changing in 2027, and what you can do about it now.
What is indoor air quality?
Indoor air quality refers to the mix of particles, gases and biological material in the air inside buildings. The things that affect it include:
- Mould spores — released when mould grows in damp conditions. Breathing mould spores can cause allergic reactions, asthma, and in serious cases respiratory infection.
- Volatile organic compounds (VOCs) — released by cleaning products, paints, furniture, flooring, aerosol sprays and air fresheners. Many VOCs are harmful at sustained indoor concentrations.
- Dust and particulate — fine particles from cooking, cleaning, textiles, building materials and outdoor pollution that penetrates indoors. The finest particles — those below 2.5 microns — reach deep into the lungs.
- Carbon dioxide — builds up in poorly ventilated spaces. High CO2 levels cause fatigue, headaches and impaired concentration. Schools have been monitoring CO2 since 2021.
- Carbon monoxide — from faulty boilers and combustion appliances. Colourless and odourless. A serious and potentially fatal hazard.
- Radon — a naturally occurring radioactive gas that seeps from certain types of ground into buildings. A leading cause of lung cancer in non-smokers in affected areas.
Why does this matter for your health?
Poor indoor air quality is linked to a wide range of health conditions — some immediate, some developing over years of exposure:
- Respiratory conditions — asthma, bronchitis, COPD
- Allergic reactions — hay fever-like symptoms, skin irritation, eye irritation
- Headaches, fatigue and difficulty concentrating — often linked to CO2 and VOC levels in poorly ventilated spaces
- Long-term lung disease from sustained fine particulate exposure
- Mould-related illness — from prolonged exposure to damp and mould in the home
Awaab Ishak, the two-year-old child after whom Awaab's Law is named, died in 2020 from a respiratory condition caused by prolonged mould exposure in his family's social housing flat. His death was a turning point in how seriously the UK now treats indoor air quality as a health issue.
What is changing in 2027?
Three pieces of regulation are converging to create the UK's first framework of mandatory indoor air quality standards:
- The UK Indoor Air Quality Strategy — sets targets for measurable indoor air pollutant levels in public and commercial buildings.
- The Environment Act 2021 — creates legally binding air quality targets and extends air quality regulation indoors.
- Approved Document F (March 2027) — updated ventilation standards for new buildings and any significant building work. From March 2027, any home renovation, extension or refurbishment that requires building regulations approval will need to meet new ventilation standards designed to ensure adequate fresh air circulation.
What this means practically is that new homes and significantly renovated homes will be built or upgraded to a standard that actively manages indoor air quality — not just keeps the damp out.
What has already changed
Some of this is not waiting for 2027. The Housing Health and Safety Rating System was overhauled in June 2026 to include Indoor Air Pollutants as a formally scored and enforceable hazard. This means Environmental Health Officers can now act on indoor air quality issues — including VOCs from cleaning chemicals and particulate from building materials — in the same way they act on damp, cold or structural problems.
Awaab's Law (in force October 2025) requires social landlords to investigate and fix damp and mould within strict timescales. Phase 2 takes effect 30 November 2026. The Renters' Rights Act 2025 is extending similar rights to private tenants.
What can you do now?
You do not need to wait for regulation to improve the air quality in your home. Some practical steps:
- Ventilate properly — open windows when cooking, showering or cleaning. Use extractor fans. Let fresh air through even in winter — short bursts are better than none.
- Control moisture — condensation is the most common cause of mould in UK homes. Dry clothes outside where possible, use lids on pans when cooking, and make sure your boiler and heating system is working properly.
- Deal with mould early — small patches of mould dealt with quickly prevent the larger problem. If mould keeps returning despite surface cleaning, the moisture source has not been fixed.
- Choose cleaning products carefully — heavily fragranced cleaning products and aerosol sprays can significantly increase VOC levels indoors. Low-fragrance or fragrance-free alternatives are better for indoor air quality.
- If you are a tenant with a damp or mould problem — report it to your landlord in writing, keep a record of the report, and know your rights. Under Awaab's Law, social landlords must investigate within 14 days. Under the Homes (Fitness for Human Habitation) Act, all tenants can take action if their home is unfit.
Where to find out more
Indoor Air Aware (indoorairaware.co.uk) is a UK community interest organisation founded by Lisa Malyon, who was hospitalised with pneumonia caused by mould exposure in her own home. Its expert panel includes professors of medical mycology, WHO advisors and paediatric respiratory consultants. It provides free information, healthy home visits and education for households, landlords and professionals.
Why mould grows in autumn and winter → | How to reduce condensation in your home → | Your rights if your landlord is not fixing damp or mould → | Indoor Air Quality Regulation 2027 — full detail →
