Passivhaus and EnerPHit · Northamptonshire
Passivhaus and EnerPHit windows in Daventry
From the first measure to the handover pack, we handle Passivhaus and EnerPHit windows for homes in Daventry and the rest of Northamptonshire.

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 Daventry
On the shortest day, Daventry gets about 7 h 41 min of daylight and the midday sun reaches only about 14° above the horizon. Low winter sun means north-facing rooms here gain little solar heat, which is where triple glazing’s lower heat loss helps most.
Guide prices in Daventry
| 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
The rules for replacement windows in England are set by Approved Document L (2021 edition, with 2023 amendments): 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.
Before ordering: 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
You will know exactly what you are buying: the quote states the unit build-up, frame, finish, fitting work and how Building Regulations compliance is handled. On fitting day each opening is replaced and closed up before the team moves on.
- Guide prices published, not hidden
- No pressure: the quote is yours to keep
- Frames, glass and fitting in one contract
- Advice on planning and consents before you order
Questions from Daventry
What is EnerPHit?
The Passive House Institute’s standard for retrofitting existing buildings, with slightly relaxed targets compared with new Passivhaus builds.
Do Passivhaus windows have to be certified?
Not always, but certified components make the certification process simpler. Ask and we will price certified systems.
How long does it take to get Passivhaus and EnerPHit windows fitted in Daventry?
After the survey, typical manufacture time is 8 to 14 weeks, and most homes are fitted in 1 to 4 days.
Do you fit Passivhaus and EnerPHit windows in Daventry?
Yes. We arrange surveys and fitting in Daventry and across Northamptonshire. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
Nearby
Also near Daventry: Rugby (14 km), Northampton (19 km), Royal Leamington Spa (25 km) and Banbury (25 km).
Other products in Daventry
- 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 Daventry: 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.
