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Passivhaus and EnerPHit · Hertfordshire

Passivhaus and EnerPHit windows in Stevenage

Passivhaus and EnerPHit windows for homes in Stevenage: measured on a free survey, made to order and fitted by installation teams working for us across Hertfordshire.

SG1Postcode district
1.4U-value limit, England (W/m²K)
7h 46mDaylight, 21 Dec
15°Midday sun, 21 Dec
Timber-clad low-energy house with deep-set windows and external shading

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 Stevenage

By midsummer Stevenage has about 16 h 43 min of daylight, but in December only around 7 h 46 min, with the noon sun at about 15°. Triple glazing keeps more heat in during those long, dark months; big south and west windows may suit solar-control glass for summer.

Guide prices in Stevenage

GuideSupply 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

England requires replacement windows to achieve 1.4 W/m²K, or a Window Energy Rating of band B or better, which good triple glazing passes comfortably. 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

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.

  • Free survey and a written quote fixed for the specification
  • Glass build-up and whole-window U-value on every quote
  • Written handover pack at the end of the job
  • Guarantees on frames, units and fitting in writing

Questions from Stevenage

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.

Do you fit Passivhaus and EnerPHit windows in Stevenage?

Yes. We arrange surveys and fitting in Stevenage and across Hertfordshire. Send your postcode and the windows or doors you want replaced, and we will book a free survey.

Do I need permission for Passivhaus and EnerPHit windows in Stevenage?

In England, like-for-like replacements on a house are normally permitted development; flats need permission if the change alters their appearance, Article 4 areas may need permission, and listed buildings need listed building consent. Check whether your street is in a conservation area or covered by an Article 4 direction before changing the style.

Nearby

Also near Stevenage: Hitchin (8 km), Letchworth Garden City (9 km), Welwyn Garden City (11 km) and Harpenden (14 km).

Other products in Stevenage

Passivhaus and EnerPHit in Stevenage: 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.

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