Replacement windows are new frames and sealed double- or triple-glazed units fitted into your existing openings after the old windows are taken out, improving warmth, security and noise reduction while meeting current building regulations.
If you live in Stevenage and are weighing up replacement windows, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across SG1 and SG2, and a typical project of this kind in the East of England lands somewhere in the £4,700–£9,400 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £4,700–£9,400 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- SG1 and SG2
- Planning rules
- England
- Local area
- Hertfordshire
- Survey
- Free, with a written quote
How much do replacement windows cost in Stevenage?
These are guide costs, not quotes. For replacement windows in Stevenage the range is £4,700–£9,400, VAT included, reflecting prices in the East of England that are about 5% above the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Stevenage |
|---|---|---|
| One to three windows | Replacing a few problem windows, such as a bay or a rotten kitchen window, in uPVC. | £750–£3,200 |
| Whole house in uPVC | Eight to ten standard uPVC casement windows on a typical 3-bed semi, fitted and finished. | £4,700–£7,900 |
| Whole house in aluminium or flush sash | Premium frames, colours or period styles across a typical 3-bed home. | £7,900–£14,500 |
What moves the price up or down:
- Number and size of windows, including bays and large picture windows
- Glazing type: double, triple, acoustic, obscure or toughened
- Window style, such as sash, flush sash or tilt-and-turn
- Upper-floor access, scaffolding and the condition of reveals and sills
What’s included?
- Measured survey of every opening, with sizes checked before manufacture
- Double-glazed units as standard, with triple glazing as an option
- Careful removal and disposal of the old frames and glass
- Fixings, packers, foam and weather seals to suit your wall type
- Trickle vents, escape hinges and safety glass where regulations require
- Building regulations sign-off arranged and paperwork handed over
What are homes like around Stevenage?
Hertfordshire is home to the first garden cities, Letchworth and Welwyn Garden City, and the post-war new towns of Stevenage, Hatfield and Hemel Hempstead. Watford and St Albans have Victorian terraces and Georgian streets, interwar semis line the commuter suburbs, and brick-and-flint cottages appear in Chiltern villages to the west.
New-town and garden-city homes often suit extensions, window replacement and roofline renewal, though some garden-city estates have their own design guidance. Victorian terraces commonly take loft rooms and side-return extensions.
In Stevenage, as elsewhere in Hertfordshire, we take the building's age and construction into account before recommending anything, because both can change what is involved in replacement windows.
Permissions for replacement windows in Stevenage
As Stevenage is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
Replacing windows and doors on a house is usually permitted development in England when the new ones look broadly similar to the old. Flats, listed buildings and homes covered by an Article 4 direction can need consent, and conservation areas may limit materials or styles.
Replacement windows and external doors must meet Building Regulations for energy efficiency, ventilation and, on upper floors, escape. The work is either self-certified by an installer registered with a competent person scheme or signed off by building control.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
A visit to your home
A free survey comes first. It gives us what we need to price replacement windows properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Dates and permissions
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
Why homeowners choose us
Replacement windows in Stevenage: questions
Will new windows stop condensation?
New windows reduce condensation on the glass because the inner pane stays warmer, but they do not remove the moisture in the air that causes it. Modern frames are also more airtight, so ventilation matters more after replacement. We fit trickle vents where regulations require them, and we suggest using extractor fans and opening windows regularly. If walls are damp or mouldy, it is worth looking at ventilation and heating at the same time.
Do I need planning permission in Stevenage?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Stevenage is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
How do I look after new uPVC or aluminium windows?
Caring for new windows is simple: wash frames and glass with warm soapy water a few times a year, avoiding abrasive cleaners and solvents. Clear the drainage slots at the bottom of the frame so rainwater can escape, and put a drop of light oil on hinges and locking points once a year. Check seals and the sealant around the outside every few years, and replace any that have cracked or shrunk.
How long does it take to fit windows in a house?
Fitting replacement windows in a typical 3-bed house usually takes one to two days on site. We take out and fit one window at a time, so each room is weathertight again within an hour or two. Bays, sash windows and homes needing scaffolding take longer. Manufacture comes first: made-to-measure frames typically take a few weeks to arrive after the survey and your order are confirmed.
Do you cover Hitchin, Letchworth Garden City and Welwyn Garden City?
Yes. As well as Stevenage, we cover Hitchin, Letchworth Garden City and Welwyn Garden City and the rest of Hertfordshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Near Stevenage
We welcome enquiries from all SG1 and SG2 postcodes in Stevenage, plus Hitchin, Letchworth Garden City and Welwyn Garden City. Each one gets the same survey at no charge and a written price fixed for the work described.

