St James's, Greater London
Positive input ventilation (PIV) in St James's
Loft or wall units that gently push filtered air into the home to tackle condensation. Covering St James's and SW1Y, W1J and W1S.
- From £950 inc VAT per home
- Free survey
If your St James's flat has no loft, a wall-mounted PIV unit does the same job through an outside wall.
Work in St James's follows the rules for England and finishes with a written record of what was fitted and how it was set up.
PIV in St James's at a glance
- Town
- St James's, Greater London
- Postcode districts
- SW1Y, W1J and W1S
- Nearby
- West End (under a mile), Soho (under a mile) and Westminster (1 mile)
- Price region
- London
- Survey
- Free survey (UK mainland)
What the work involves
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.
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 St James's
| 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.
Signs it is time to call us
- 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
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.
Questions from St James's
What is the price of a PIV unit in St James's?
Guide prices for St James's 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 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.
Will PIV make my house cold?
Most units temper or reduce the flow when the incoming air is cold, and a heated unit warms it. Placed correctly on the landing, the air spreads gently rather than blowing on anyone.
Is the survey free in St James's?
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 St James's?
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.
Tell us whether your St James's home has a loft and we can price a PIV unit before visiting.
PIV near St James's
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Answer a few questions for a price range, or send photos and we will come back to you with a written quote.