Forest Hill, Greater London
Positive input ventilation (PIV) in Forest Hill
Loft or wall units that gently push filtered air into the home to tackle condensation. Covering Forest Hill and SE4, SE6 and SE23.
- From £950 inc VAT per home
- Free survey
Condensation in Forest Hill homes usually has one of two answers: better extract fans, or PIV as well.
Whether the property is in the middle of Forest Hill 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 Forest Hill at a glance
- Town
- Forest Hill, Greater London
- Postcode districts
- SE4, SE6 and SE23
- Nearby
- Crofton Park (under a mile), Perry Vale (1 mile) and Catford (1 mile)
- Price region
- London
- Survey
- Free survey (UK mainland)
PIV for Forest Hill homes
It does not replace extract fans: kitchens and bathrooms still need their own extract to remove steam at source. On survey we check the loft, the landing position and the existing fans, and we tell you if PIV is not the right answer.
PIV with fan upgrades
PIV plus humidity-controlled extract fans in the kitchen and bathroom for the most stubborn condensation.
Loft-mounted PIV
The most common option for houses with a loft. Usually fitted in half a day.
Guide prices in Forest Hill
| 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 |
These ranges use our London rates. Prices include VAT at 20%. You get a fixed written price before any work is booked.
When to get it looked at
- Washing dried indoors makes everything worse
- You have no loft but still need whole-flat ventilation (wall unit)
- Streaming windows on most mornings in winter
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 Forest Hill
Is the survey free in Forest Hill?
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.
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.
How much does PIV cost to run?
A standard PIV unit uses very little electricity, comparable to a low-energy light bulb on normal speed. A heated unit costs more in cold spells because the heater switches on when loft air is cold.
How do I get a price for a PIV unit in Forest Hill?
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.
What area around Forest Hill do you work in?
All of Greater London. Near Forest Hill that includes Crofton Park, Perry Vale, Catford and Ladywell.
We will check the existing fans in your Forest Hill home at the same visit, because PIV works best with them working.
PIV near Forest Hill
More services in Forest Hill
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.