Projects
Passivhaus and EnerPHit windows
For Passivhaus and EnerPHit work the window is only as good as its installation. We supply low-energy triple glazed systems, including Passive House Institute certified components on request, and agree installation position, insulation and airtightness details with your designer before ordering. The certification belongs to the product and the building, so we give you the data your designer needs.
Summary
Passivhaus is a building standard from the Passive House Institute; EnerPHit is its version for retrofits. Windows on these projects typically need whole-window U-values of 0.85 W/m²K or lower once installed, which in practice means triple glazing, warm-edge spacers, insulated frames and careful airtight installation.
What you get
| Target performance | Installed Uw 0.85 W/m²K or lower |
|---|---|
| Glass | Triple, wide cavities, two low-e panes, warm-edge spacers |
| Frames | Deep insulated uPVC, timber or alu-clad timber |
| Installation | Airtightness tapes, insulated fixing, position agreed in the wall |
| Data | Frame and glass values for PHPP |
| Typical lead time | 8 to 14 weeks |
Guide prices
Guide prices for typical projects; your quote is built from your own survey or drawings.
uPVC low-energy window
medium, deep frame, Uw about 0.8 or better
£1,395 – £1,795inc VAT · £1,160 – £1,495 ex VAT
- Deep multi-chamber frame
- Airtightness tapes and insulated fixing
- Installation details recorded
Timber low-energy window
medium, thermally broken
£2,395 – £2,995inc VAT · £1,995 – £2,495 ex VAT
- Engineered timber, deep section
- Airtightness tapes and insulated fixing
- Installation details recorded
Alu-clad timber low-energy window
medium, certified-component systems on request
£2,695 – £3,395inc VAT · £2,245 – £2,830 ex VAT
- Timber inside, aluminium outside
- Airtightness tapes and insulated fixing
- Installation details recorded
Guide prices, supply and fit. The written quote after your survey fixes the price for the specification shown; anything extra is agreed with you first.
Is it right for your home?
A good fit for
- Passivhaus and EnerPHit projects
- Deep retrofits with external wall insulation
- Clients who want measured, not assumed, performance
Think twice if
- Ordinary replacements, where standard triple glazing is enough
- Projects without a designer or energy model
Options
- Certified-component systems on request
- Overheating control: solar-control glass, external shading
- Tilt and turn openers
- Lift-and-slide doors
- Installation records for certification
Solar gain is part of the design
Triple glazing lets in less solar heat (a g-value around 0.5 against about 0.6 to 0.72 for double). On Passivhaus projects that is balanced in the energy model: south glass may use a higher g-value unit, and east and west glass may need shading to avoid overheating.
Data for your designer
Your designer needs the frame U-value, glass U-value and g-value, spacer psi-value and installation psi-value for PHPP. We provide the data for the systems quoted.
Building Regulations by nation
| Nation | Replacement windows | Sign-off |
|---|---|---|
| England | 1.4 W/m²K, or a Window Energy Rating of band B or better | Competent person scheme or building control |
| Wales | 1.4 W/m²K, or a Window Energy Rating of band B or better | Competent person scheme or building control |
| Scotland | 1.6 W/m²K | No building warrant for a straight replacement; must meet the standards |
| Northern Ireland | 1.6 W/m²K, or a Window Energy Rating of band C or better | No building notice for a straight replacement; must comply |
Full regulations guide, with sources →
Questions about Passivhaus and EnerPHit
Do Passivhaus windows have to be certified?
Not always, but certified components make the certification process simpler. Ask and we will price certified systems.
Is triple glazing enough for Passivhaus?
Triple glass is the starting point. The frame, spacers and installation all have to perform too.
What is EnerPHit?
The Passive House Institute’s standard for retrofitting existing buildings, with slightly relaxed targets compared with new Passivhaus builds.
Can you fit to my designer’s details?
Yes. We agree position, fixings and airtightness details with your designer before ordering.
Related products
Alu-clad timber windows
From £1,395Warm timber inside, a weatherproof aluminium shell outside.
Learn more →
New builds and self-builds
From £11,195Window and door packages delivered and fitted to your build programme.
Learn more →
Tilt and turn windows
From £795Inward-opening windows that tilt to vent and turn to clean.
Learn more →
Fixed and picture windows
From £745Big fixed panes for views, with the weight handled properly.
Learn more →Passivhaus and EnerPHit by area
England
- Bedfordshire
- Berkshire
- Bristol
- Buckinghamshire
- Cambridgeshire
- Cheshire
- Cornwall
- County Durham
- Cumbria
- Derbyshire
- Devon
- Dorset
- East Riding of Yorkshire
- East Sussex
- Essex
- Gloucestershire
- Greater London
- Greater Manchester
- Hampshire
- Herefordshire
- Hertfordshire
- Isle of Wight
- Kent
- Lancashire
- Leicestershire
- Lincolnshire
- Merseyside
- Norfolk
- North Yorkshire
- Northamptonshire
- Northumberland
- Nottinghamshire
- Oxfordshire
- Rutland
- Shropshire
- Somerset
- South Yorkshire
- Staffordshire
- Suffolk
- Surrey
- Tyne and Wear
- Warwickshire
- West Midlands
- West Sussex
- West Yorkshire
- Wiltshire
- Worcestershire
Scotland
Passivhaus and EnerPHit: get your guide price
Use the guide-price tool, or book a free survey for a written quote that fixes the price.