Ventilation for new builds, extensions and lofts in Northamptonshire

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.

Northamptonshire has every kind of building, from old terraces to new estates and business parks, and every job is designed around the building in front of us, not a standard kit.

New builds & extensions in Northamptonshire at a glance

Area: Northamptonshire
Towns listed: 8, largest Northampton
Postcode districts: NN16, NN1, NN2, NN17, NN18 and NN14
Price region: East Midlands
Survey: Free survey (UK mainland)

How we do it

Extensions and loft conversions have their own triggers: a new wet room needs extract, a new habitable room needs background ventilation or a connection to the ducted system, and energy-efficiency work can mean the existing home needs more ventilation too. 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.

MEV or dMEV

Continuous extract systems where MVHR is not specified.

Extensions and lofts

Extract for new bathrooms and kitchens, background ventilation for new rooms.

Commissioning only

Testing and paperwork for systems installed by others.

Guide prices in Northamptonshire

Ventilation for new builds, extensions and lofts guide prices in Northamptonshire
Work	Guide price
MVHR in a new build or full renovation (fitted at first fix), 3 to 4 bedrooms (per home)	£4,850–£7,800 inc VAT
Continuous-running extract fan (dMEV) with humidity boost, flow tested (per fan)	£340–£575 inc VAT
Airflow testing and commissioning sheet for extract fans (up to 6 fans) (per home)	£140–£290 inc VAT
MVHR or MEV commissioning test, every terminal measured and recorded (per system)	£240–£385 inc VAT

East Midlands 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

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 England

English building work follows Approved Document F (2021 edition) for ventilation rates, installation and commissioning. 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

Drawings
Design
First fix
Second fix
Commission

Towns we cover in Northamptonshire

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

Are prices different in Northamptonshire?

Our guide prices are adjusted by region. In Northamptonshire we use East Midlands rates, so MVHR in a new build or full renovation (fitted at first fix), 3 to 4 bedrooms is typically £4,850 to £7,800 inc VAT per home.

Do loft conversions need ventilation?

Yes. New bedrooms need background ventilation, and a new en-suite or bathroom needs extract to outside.

Does an extension need extractor fans?

A new kitchen, bathroom, utility room or WC in an extension needs mechanical extract to meet Approved Document F in England, and new habitable rooms need background ventilation or a connection to a ducted system.

Is the survey free in Northamptonshire?

For new installations on the UK mainland, yes. The survey is free and the quote that follows is fixed and in writing. Servicing, testing and repair visits are charged, and we confirm the cost before booking.

Which rules apply to ventilation in Northamptonshire?

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.