Positive input ventilation (PIV) in Surrey

If your Surrey flat has no loft, a wall-mounted PIV unit does the same job through an outside wall.

If you are anywhere in Surrey, send the postcode and a few photos and we will tell you what we would recommend. Towns we cover include Redhill, Staines, Banstead, Leatherhead and Ewell.

PIV in Surrey at a glance

Area: Surrey
Towns listed: 35, largest Woking
Postcode districts: KT22, KT4, KT17, GU9, GU10 and KT17
Price region: South East
Survey: Free survey (UK mainland)

What positive input ventilation (PIV) involves

Many units have a temperature sensor that reduces the flow or switches to a heater module on cold days, so the incoming air does not feel like a draught. Flats without a loft use a wall-mounted unit that draws air from outside through a cored hole. PIV works well in houses and flats with general condensation on windows and cold walls.

Loft-mounted PIV

The most common option for houses with a loft. Usually fitted in half a day.

Heated PIV

A heater module tempers the incoming air in cold weather. Useful in homes where people feel draughts.

Wall-mounted PIV for flats

Draws air from outside through an outside wall. Suits flats and homes with no loft space.

Guide prices in Surrey

Positive input ventilation (PIV) guide prices in Surrey
Work	Guide price
Positive input ventilation (PIV) loft unit, supplied and fitted (per home)	£875–£1,525 inc VAT
Wall-mounted PIV unit for a flat (core drilled through an outside wall) (per flat)	£1,100–£1,875 inc VAT
Heater module or heated PIV unit (extra over a standard unit) (extra)	£160–£325 inc VAT

Guide prices using South East rates. Prices include VAT at 20%. A guide price is not a quote: we confirm a fixed price in writing first.

When to get it looked at

Streaming windows on most mornings in winter
Black mould on window reveals and in corners of bedrooms
Musty smell in wardrobes or behind furniture

Rules in England

English building work follows Approved Document F (2021 edition) for ventilation rates, installation and commissioning. It sets extract rates for kitchens, bathrooms and utilities and asks for mechanical ventilation to be commissioned and recorded.

How the job runs

Survey
Fixed quote
Install
Set up
Hand over

Towns we cover in Surrey

Questions about positive input ventilation (PIV) in Surrey

Which towns in Surrey do you cover?

All of Surrey, including Redhill, Staines, Banstead, Leatherhead and Ewell. If your town is not listed, send the postcode and we will confirm.

How much does PIV cost to install?

A loft-mounted PIV unit usually costs £795 to £1,395 including VAT supplied and fitted, and £995 to £1,695 for a wall-mounted unit in a flat. A heater module adds around £145 to £295.

Does PIV really stop condensation?

PIV reduces condensation in most homes because it dilutes moist air and keeps it moving, but it works best alongside working extract fans in the kitchen and bathroom. Leaks, rising damp or a cold bridge need fixing separately.

Are prices different in Surrey?

Our guide prices are adjusted by region. In Surrey we use South East rates, so positive input ventilation (PIV) loft unit, supplied and fitted is typically £875 to £1,525 inc VAT per home.

Is the survey free in Surrey?

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.

Most Surrey PIV jobs are done in half a day, so ask about the next available date.