Passivhaus and EnerPHit · Greater London
Passivhaus and EnerPHit windows in Isleworth
Homes in Isleworth can have Passivhaus and EnerPHit windows supplied and fitted, with surveys arranged across Greater London including TW7.
The windows and installation detail low-energy builds depend on. Passivhaus is a building standard from the Passive House Institute; EnerPHit is its version for retrofits.
Winter light and glass choice in Isleworth
In Isleworth, midday sun in late December sits around 15° high, with roughly 7 h 50 min of daylight. For windows facing north or shaded by neighbours, cutting heat loss matters more than solar gain; on open south-facing glass, ask about a higher solar-gain unit.
Guide prices in Isleworth
| Guide | Supply and fit, inc VAT |
|---|---|
| uPVC low-energy window medium, deep frame, Uw about 0.8 or better | £1,395 – £1,795 |
| Timber low-energy window medium, thermally broken | £2,395 – £2,995 |
| Alu-clad timber low-energy window medium, certified-component systems on request | £2,695 – £3,395 |
Guide prices. Your written quote after the free survey fixes the price for the specification shown.
Rules for Passivhaus and EnerPHit in England
In England, replacement windows must meet 1.4 W/m²K, or a Window Energy Rating of band B or better. Replacement windows are a controlled fitting. A competent person scheme installer (such as FENSA or Certass) self-certifies the work and notifies the council within 30 days; otherwise a building control body approves it.
Planning: Replacing windows on a house is normally permitted development if the new ones look similar. New upper-floor windows in a side wall must be obscure glazed and fixed, or open only above 1.7 m. Flats and maisonettes have no householder permitted development rights, so a change that alters their appearance needs planning permission. An Article 4 direction in a conservation area may mean permission is needed, and listed buildings need listed building consent.
How it works
The surveyor measures every opening, checks ventilation, escape windows and safety-glass zones, and talks through styles. Your written quote lists each item with its glass build-up and U-value, and the price is fixed for that specification.
- Every opening measured, including escape and vent needs
- Frames rated for the weight of triple glass
- Old windows removed and taken away
- Each opening closed up the same day
Questions from Isleworth
Do Passivhaus windows have to be certified?
Not always, but certified components make the certification process simpler. Ask and we will price certified systems.
What is EnerPHit?
The Passive House Institute’s standard for retrofitting existing buildings, with slightly relaxed targets compared with new Passivhaus builds.
Do you fit Passivhaus and EnerPHit windows in Isleworth?
Yes. We arrange surveys and fitting in Isleworth and across Greater London. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
How long does it take to get Passivhaus and EnerPHit windows fitted in Isleworth?
After the survey, typical manufacture time is 8 to 14 weeks, and most homes are fitted in 1 to 4 days.
Nearby
We also cover nearby Hounslow (2 km), Heston (2 km), Richmond (3 km) and Southall (4 km).
Other products in Isleworth
- uPVC windows
- Aluminium windows
- Timber windows
- Alu-clad timber windows
- Casement windows
- Flush casement windows
- Tilt and turn windows
- Sash windows
- Bay and bow windows
- Fixed and picture windows
- Composite front doors
- French doors
- Sliding patio doors
- Bifold doors
- Glass-only replacement
- Acoustic triple glazing
- Security glazing
- Whole-house replacement
- New builds and self-builds
- Period homes and conservation areas
- Flats and apartments
Passivhaus and EnerPHit in Isleworth: book your free survey
Written quote fixed for the specification, after a free survey. Building Regulations sign-off by a competent person scheme installer or building control, as the law requires in England.