Harrow, Greater London
Positive input ventilation (PIV) in Harrow
Loft or wall units that gently push filtered air into the home to tackle condensation. Covering Harrow and HA1, HA2, HA3 and HA5.
- From £950 inc VAT per home
- Free survey
Condensation in Harrow homes usually has one of two answers: better extract fans, or PIV as well.
Whether the property is in the middle of Harrow or one of the villages around it, the process is the same: a look at the building, a written price, then fitting and testing on the agreed day.
PIV in Harrow at a glance
- Town
- Harrow, Greater London
- Postcode districts
- HA1, HA2, HA3, HA5 and HA7
- Nearby
- Harrow on the Hill (under a mile), Headstone (1 mile) and Wealdstone (2 miles)
- Price region
- London
- Survey
- Free survey (UK mainland)
PIV for Harrow homes
PIV works well in houses and flats with general condensation on windows and cold walls. It does not replace extract fans: kitchens and bathrooms still need their own extract to remove steam at source.
Wall-mounted PIV for flats
Draws air from outside through an outside wall. Suits flats and homes with no loft space.
PIV with fan upgrades
PIV plus humidity-controlled extract fans in the kitchen and bathroom for the most stubborn condensation.
Guide prices in Harrow
| Work | Guide price |
|---|---|
| Positive input ventilation (PIV) loft unit, supplied and fitted (per home) | £950–£1,675 inc VAT |
| Wall-mounted PIV unit for a flat (core drilled through an outside wall) (per flat) | £1,200–£2,025 inc VAT |
| Heater module or heated PIV unit (extra over a standard unit) (extra) | £175–£355 inc VAT |
Guide prices using London 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
- The house feels stuffy and damp rather than cold
- Washing dried indoors makes everything worse
- You have no loft but still need whole-flat ventilation (wall unit)
Rules that apply in England
In England, ventilation is covered by Part F of the Building Regulations and its guidance, Approved Document F (2021 edition). It sets extract rates for kitchens, bathrooms and utilities and asks for mechanical ventilation to be commissioned and recorded.
Questions from Harrow
What is the price of a PIV unit in Harrow?
Guide prices for Harrow use London rates: positive input ventilation (PIV) loft unit, supplied and fitted is typically £950 to £1,675 inc VAT per home. We confirm a fixed price in writing before any work starts.
How long does PIV installation take?
A loft unit is normally fitted in two to four hours, including the diffuser and electrical connection.
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.
Is the survey free in Harrow?
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.
How do I get a price for a PIV unit in Harrow?
Use the guide price tool, the form on this page, live chat, WhatsApp or call 0800 088 6341. A postcode and a couple of photos help us give you a useful answer first time.
We will check the existing fans in your Harrow home at the same visit, because PIV works best with them working.
PIV near Harrow
More services in Harrow
Get a guide price in two minutes
Answer a few questions for a price range, or send photos and we will come back to you with a written quote.