Ventilation for new builds, extensions and lofts in Gwent

New homes, extensions and loft conversions need ventilation that meets the building regulations and is tested before sign-off. We design the system, install it at the right stage of the build, measure the airflows and provide the commissioning information building control asks for.

Our team is based in Great Barr, Birmingham, and we work throughout Gwent, from Caerphilly, Risca, Gelligaer, Blackwood and Newport. We survey first, free of charge for new installations on the mainland, then send a fixed written quote.

New builds & extensions in Gwent at a glance

Area: Gwent, Wales
Towns listed: 17, largest Newport
Postcode districts: CF81, CF82, NP8, NP22, NP22 and NP23
Price region: Wales
Survey: Free survey (UK mainland)

How we do it

We work for self-builders, small developers, builders and architects. Fitting ducts at first fix is far cheaper than retrofitting, so it pays to involve us before the ceilings go up.

Commissioning only

Testing and paperwork for systems installed by others.

MVHR for new builds

Design, first fix, second fix and commissioning for whole-home heat recovery.

MEV or dMEV

Continuous extract systems where MVHR is not specified.

Guide prices in Gwent

Ventilation for new builds, extensions and lofts guide prices in Gwent
Work	Guide price
MVHR in a new build or full renovation (fitted at first fix), 3 to 4 bedrooms (per home)	£4,700–£7,550 inc VAT
Continuous-running extract fan (dMEV) with humidity boost, flow tested (per fan)	£330–£575 inc VAT
Airflow testing and commissioning sheet for extract fans (up to 6 fans) (per home)	£140–£280 inc VAT
MVHR or MEV commissioning test, every terminal measured and recorded (per system)	£235–£375 inc VAT

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

When to get it looked at

Your SAP assessor has assumed a particular ventilation system
You are adding a bathroom or kitchen in an extension or loft
You are insulating and re-windowing an existing home

Rules in Wales

Wales has its own Part F ventilation guidance, published by the Welsh Government, and work is checked by building control. We design to the Welsh rates and commission mechanical systems so the results can be recorded.

How the job runs

Drawings
Design
First fix
Second fix
Commission

Towns we cover in Gwent

Questions about ventilation for new builds, extensions and lofts in Gwent

Which rules apply to ventilation in Gwent?

In Wales, the Welsh Government's own Approved Document F (2022 edition) applies to ventilation in homes, with a new edition taking effect on 4 March 2027. Rented homes must be fit for human habitation under the Renting Homes (Wales) Act 2016, and workplaces must be ventilated under the Workplace (Health, Safety and Welfare) Regulations 1992.

When should MVHR be fitted in a new build?

MVHR ducts should go in at first fix, after the structure and before plasterboard. Planning it at design stage avoids clashes with joists and steels.

How much does MVHR cost in a new build?

For a 3 to 4 bedroom new build, MVHR fitted at first fix usually costs £4,950 to £7,950 including VAT. VAT on new-build work can differ, so we confirm the treatment on your quote.

Which towns in Gwent do you cover?

All of Gwent, including Caerphilly, Risca, Gelligaer, Blackwood and Newport. If your town is not listed, send the postcode and we will confirm.

Are prices different in Gwent?

Our guide prices are adjusted by region. In Gwent we use Wales rates, so MVHR in a new build or full renovation (fitted at first fix), 3 to 4 bedrooms is typically £4,700 to £7,550 inc VAT per home.