Airflow testing and commissioning in Dorset

Airflow testing measures how much air each fan or valve actually moves, using a calibrated flow hood, and records it against the required rates. It is how you prove a ventilation system works, and for new homes it is part of the building regulations.

Our team is based in Great Barr, Birmingham, and we work throughout Dorset, from Bournemouth, Poole, Weymouth, Christchurch and Ferndown. Visits for this work are charged, with the price agreed before we arrive.

Airflow testing in Dorset at a glance

Area: Dorset
Towns listed: 14, largest Bournemouth
Postcode districts: DT3, DT4, DT6, DT8, DT11 and BH19
Price region: South West
Survey: Charged visit, price agreed first

How we do it

Approved Document F expects mechanical ventilation in new dwellings to be tested with a flow device that has been calibrated within the last 12 months, and the results recorded on a commissioning sheet. The person commissioning should be registered with a competent person scheme for ventilation or show evidence of competence; we tell you who will sign your sheet when we quote. Testing is also useful outside new builds: it shows landlords and homeowners whether existing fans meet the rates, and it is the first step in rebalancing an MVHR system that no longer feels right.

Extract fan tests

Each fan measured and compared with the Part F rate for the room.

MEV and dMEV commissioning

Trickle and boost rates measured and set.

MVHR commissioning

Supply and extract at every valve measured and balanced.

Guide prices in Dorset

Airflow testing and commissioning guide prices in Dorset
Work	Guide price
Airflow testing and commissioning sheet for extract fans (up to 6 fans) (per home)	£150–£305 inc VAT
MVHR or MEV commissioning test, every terminal measured and recorded (per system)	£255–£410 inc VAT
Rebalance and recommission an existing MVHR system (per system)	£255–£465 inc VAT

South West rates shown. Prices include VAT at 20%. The fixed price is confirmed in writing after we have seen the job.

Signs it is time to call us

After rebalancing or extending a system
Building control needs a commissioning sheet
You are selling a new build and the paperwork is missing

Rules in England

In England, ventilation is covered by Part F of the Building Regulations and its guidance, Approved Document F (2021 edition). For homes, it sets minimum extract rates such as 15 litres a second for a bathroom and 30 or 60 for a kitchen, and expects mechanical systems to be airflow-tested.

How the job runs

Book
Measure
Adjust
Record
Advise

Towns we cover in Dorset

Questions about airflow testing and commissioning in Dorset

Are prices different in Dorset?

Our guide prices are adjusted by region. In Dorset we use South West rates, so airflow testing and commissioning sheet for extract fans (up to 6 fans) is typically £150 to £305 inc VAT per home.

Is testing a legal requirement?

For new dwellings in England, mechanical ventilation must be commissioned and the results given to building control. For existing homes it is good practice and useful evidence.

How long does it take?

Most homes take under an hour; a full MVHR balance can take two to three hours.

Is the survey free in Dorset?

This is a charged visit because it is servicing, testing or repair work. We tell you the cost before booking. Surveys for new installations on the UK mainland are free.

Which rules apply to ventilation in Dorset?

In England, ventilation in new and altered homes is covered by Approved Document F of the Building Regulations. Landlords also have duties under the Housing Health and Safety Rating System, and workplaces must be ventilated under the Workplace (Health, Safety and Welfare) Regulations 1992.