Indoor Air Quality Testing near you

Appendix B of Approved Document F Volume 1 publishes a table of indoor air pollutant guidance values, based on the World Health Organization's Guidelines for Indoor Air Quality: Selected Pollutants from 2010 and Public Health England's Indoor Air Quality Guidelines for Selected Volatile Organic Compounds in the UK from 2019. It gives carbon monoxide at 100 mg/m³ over 15 minutes, 30 mg/m³ over an hour and 10 mg/m³ over eight hours; nitrogen dioxide at 200 µg/m³ over an hour and 40 µg/m³ over a year; formaldehyde at 100 µg/m³ over 30 minutes and 10 µg/m³ over a year; and total volatile organic compounds at 300 µg/m³ over eight hours.

Those values exist to define ventilation rates in the design of a dwelling. They are not a compliance test you run on a finished house, and the document is careful about the last of them: it notes that the total volatile organic compound metric is representative of all airborne indoor VOC concentrations and should not be used as a direct indicator of health, being a simplified metric for the purposes of ventilation control strategies. It also says no safe levels can be recommended for benzene or trichloroethylene, so they were not used in defining ventilation rates, and that the best strategy for reducing their indoor concentration may be to control them at source.

A separate table in the same document lists limit values from Schedule 2 to the Air Quality Standards Regulations 2010, including fine particulate matter and nitrogen dioxide. Those are ambient outdoor air quality limits, used in Approved Document F to decide when a dwelling's ventilation intakes need protecting from outdoor pollution. They are not indoor standards, and quoting them as though they were is a common sleight of hand.

A single reading taken during a one-hour visit tells you about that hour. Indoor air varies enormously with occupancy, cooking, weather, whether windows have been open and what was cleaned that morning, so a measurement worth acting on is logged over days rather than captured once, and it records what was happening at the same time. A carbon dioxide log that shows a bedroom climbing steadily through the night and falling when the door is opened is an actionable result; a mid-afternoon spot reading in an empty room is not.

The values in Approved Document F themselves make this point, because almost all of them are averaging periods rather than instantaneous limits — 15 minutes, an hour, eight hours, a year. A number without its averaging period attached cannot be compared with them at all. Ask any surveyor what averaging period their instrument reports and over how long they intend to log.

Placement matters as much as duration. Measure in the room with the problem, at roughly head height where people spend time, away from the window that is opened and away from the appliance being blamed. If mould is the concern, the reading that matters is the temperature of the cold wall alongside the humidity of the room, because that combination is what the moisture criterion is really about.

In many homes the honest advice is to spend the money on the building rather than on the measurement. Where the problem is condensation and mould, the cause is generally identifiable without instrumentation and the fix is ventilation, heating and insulation. Where it is cooking smells and moisture, the fix is an extract that goes outside. NICE's guideline on indoor air quality at home puts source removal first and ventilation second for exactly this reason, and COMEAP's 2025 response records that the committee found buildings varied too much to make specific recommendations about interventions such as air purifiers.

Measurement earns its cost in three situations. When you have made a change and want to know whether it worked, a before-and-after log is the only way to tell. When there is a dispute — with a landlord, a builder or a neighbouring business — a dated record with its methodology attached is evidence in a way that an opinion is not. And when the suspected pollutant cannot be sensed, radon being the clear case, testing is the only route to knowing at all.

Where a rented home is involved, the route is usually enforcement rather than private testing. English councils assess hazards including damp and mould in housing under the Housing Health and Safety Rating System, and social housing in England now has statutory timescales for investigating and acting on significant damp and mould hazards. A tenant's first step is a written report to the landlord and then the council, not a paid survey.

Prices vary enormously because the work does. A short walk-round with a handheld monitor is a different product from a logged multi-room survey over a week, which is different again from laboratory analysis of sampled air for individual compounds. What moves a quotation is the number of pollutants covered, whether the instruments are logged or handheld, how long they are on site, how many rooms are included, whether samples go to a laboratory, and whether the deliverable is a set of readings or an interpreted report with recommendations you can act on.

LokalMatch makes the introduction and leaves the judgement to you. Describe what you are worried about once, with your postcode — the room, the symptom and anything you have already changed — and surveyors and indoor environment specialists working in your area get in touch. Homeowners are not charged; pros pay for the requests they receive. LokalMatch does not carry out testing, does not set fees and does not vet, rank or recommend anyone who replies, so ask each of them what they will measure, over what period, and against what published value before you agree anything.