On-site commissioning and flow rate verification for all mechanical ventilation systems — intermittent extract, continuous MEV, and whole-house MVHR — to confirm Part F compliance at completion.
Tell us your ventilation system type and we'll confirm availability and pricing within one working day.
Thanks — we'll confirm availability and pricing within one working day.
Part F recognises several approaches to mechanical ventilation. The test scope, flow rate targets, and commissioning requirements differ for each. We cover all of them.
These are the minimum rates per Approved Document F 2021. Your design specification may require higher rates — we confirm the applicable targets from your design documents before testing.
MVHR flow rates are commissioned against the design specification for the installed unit, not a generic minimum. We obtain design data from the system installer before commissioning.
A typical visit for a single dwelling takes two to three hours. For MVHR commissioning, allow additional time for balancing and fine-tuning across all terminals.
Part F 2021 introduced updated ventilation requirements for new dwellings. The regulations apply to all habitable rooms and wet areas, and require evidence of commissioning and flow rate compliance as part of the as-built pack submitted to Building Control.
For SAP calculations, using product-specific fan powers from your installed MVHR or DMEV unit produces a better result than defaulting to generic values. We record the actual installed product details during commissioning and can pass these directly to your SAP assessor — or to our own team if we're handling the SAP calculation too.
Ventilation testing is often overlooked until late in the programme — partly because the system appears to be working and partly because it's easy to assume commissioning was done by the installer. But a commissioning certificate from the installer is not the same as a third-party compliance test certificate, and Building Control will typically require an independent result.
Years of on-site testing across the Midlands and South West have shown the same issues coming up repeatedly. All are fixable before the test date if caught early.
Under SAP 10 (Part L 2021), the specific fan power (SFP) of your installed ventilation system is a direct input into the energy calculation. Using product-specific SFP values from your actual installed MVHR or DMEV unit will produce a better SAP result than relying on default generic values — which assume higher power consumption than most modern systems actually use.
When we commission your ventilation system, we record the make, model, and tested operating data of the installed unit. If we're also carrying out your SAP calculation, we pass this data directly into the as-built assessment — no additional coordination required.
This connection between ventilation commissioning and SAP performance is one of the most commonly missed optimisation opportunities on new build schemes. It costs nothing extra to capture if both services are handled by the same team.
We test and commission all ventilation system types — intermittent extract, continuous MEV, and whole-house MVHR. Often coordinated with air tightness testing on the same site visit.
Ventilation flow rate testing and MVHR commissioning for new builds and apartments across Birmingham, Solihull, Coventry, Wolverhampton, and the wider West Midlands. Part F compliance certificates for Building Control.
Part F ventilation testing across Bristol, Bath, South Gloucestershire, and the surrounding South West. Intermittent extract, MEV, and MVHR systems tested and certified.
Based in Worcester — ventilation commissioning across Malvern, Droitwich, Evesham, Bromsgrove, and Redditch. Our home county with the fastest response times.
Ventilation flow rate testing for residential developments across Cheltenham, Gloucester, Stroud, Tewkesbury, and the Cotswolds. Often combined with air tightness testing to reduce site visits.
Part F ventilation commissioning across Oxford, Banbury, Bicester, Witney, and the wider Oxfordshire area. All system types tested including DMEV and whole-house MVHR.
Our ventilation test certificates are valid across the whole of England and Wales. We regularly commission systems outside our core regions — contact us wherever your development is.
Looking for ventilation testing near you? Whether you need MVHR commissioning on an apartment block in Birmingham, extract fan testing on a housing development in Bristol, or Part F sign-off on a conversion in the Cotswolds — we deliver compliant results coordinated with your completion programme. Call 01386 365145 or email us to book.
Not always. Approved Document F 2021 requires that ventilation systems be commissioned and that commissioning data is provided to Building Control. Many Building Control bodies require this to come from an independent third-party test rather than a certificate self-issued by the system installer.
If you are unsure what your local Building Control body requires, contact them directly or ask us — we can confirm what's needed for your area before you book.
Ventilation systems should be fully installed, powered, and accessible before testing. For intermittent fans, this typically means finishes are complete and fans have been running for a settling-in period. For MVHR commissioning, the system should be fully installed with all ductwork connected and terminated, but floor coverings do not need to be in place.
Ventilation testing can usually be combined with air tightness testing on the same visit, which is worth planning for — particularly if both tests are required for the same property.
Mechanical Extract Ventilation (MEV) extracts stale air from wet rooms but does not supply fresh air to habitable rooms — background ventilators or trickle vents in windows provide the supply path. MEV systems are simpler and cheaper to install, and suitable for most housing schemes.
Mechanical Ventilation with Heat Recovery (MVHR) both extracts stale air and supplies fresh air via a central unit with a heat exchanger. This allows heat from the outgoing stale air to warm the incoming fresh supply, reducing heating demand. MVHR is more complex to commission and balance, but produces better SAP results and is preferred in very airtight or Passivhaus-standard buildings.
Decentralised Mechanical Extract Ventilation (DMEV) fans run continuously at a low background rate rather than switching on and off with use. This provides constant air change without the energy spikes of intermittent fans and avoids the moisture build-up that can occur between infrequent fan operations.
For SAP purposes, DMEV fans allow product-specific fan power values to be used in the calculation rather than a generic default — this typically improves your SAP score if a well-specified efficient fan is selected. We record the installed product details during commissioning and can provide these to your SAP assessor.
Yes, and we actively encourage this for developments that require multiple completion tests. Ventilation testing is commonly combined with air tightness testing on the same site visit, reducing programme disruption and site attendance costs.
If we are also carrying out your SAP calculations, the ventilation commissioning data is fed directly into the as-built assessment on the same day — avoiding the delays that typically occur when these are handled by different contractors.
Before testing, all ventilation systems must be fully installed and powered. Terminal covers should be in place but removable. For MVHR systems, design documentation and the system specification should be available on site. Background ventilators (trickle vents) must be open during intermittent fan testing.
We send a preparation checklist at the point of booking. If you have any concerns about site readiness, contact us before the test day — it saves time and avoids wasted visits.
Tell us your system type and number of dwellings and we'll confirm the test scope, check availability, and quote for a combined visit if air tightness testing is also needed.
Send us your project details and we'll confirm the tests required, availability, and pricing — usually within one working day.
We'll review your details and come back within one working day.