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.
Homeowners in Welwyn Garden City usually consider replacement windows for one of a few reasons: something has worn out, the house no longer suits the way they live, or they are getting it ready to sell. We visit, agree a specification and put a fixed price in writing. Most jobs like this take 1–2 days on site for a typical house, and we work across Hertfordshire, including Hatfield, Hertford and St Albans.
- Guide price
- £4,700–£9,400 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- AL7 and AL8
- Planning rules
- England
- Local area
- Hertfordshire
- Survey
- Free, with a written quote
Replacement windows prices in Welwyn Garden City
No two jobs cost exactly the same, but the ranges below give a fair picture of replacement windows in Welwyn Garden City. Pricing for the East of England runs about 5% above the national guide, and the overall guide is £4,700–£9,400 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Welwyn Garden City |
|---|---|---|
| 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 |
Your price depends mostly on:
- 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
Scope of the work
- Made-to-measure frames in your chosen material, colour and style
- 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
Local housing and replacement windows
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.
Generally dry with chalk and clay soils; clay areas can move in long dry spells, and mature trees near houses need considering for foundations.
So when we survey a Welwyn Garden City property for replacement windows, the first step is working out how it was built and what has been changed since.
Do you need permission in Welwyn Garden City?
Planning law differs across the UK. For a home in Welwyn Garden City, it is the England rules below that count, and we check them with the council ahead of any 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.
The four stages
Survey and measure
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.
Quote in writing
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for replacement windows.
Dates and permissions
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Welwyn Garden City property.
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.
How we work
Frequently asked questions
Do I need planning permission for new windows?
Planning permission is not usually needed to replace windows with similar ones, but it depends on the size and style of the change, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. Listed buildings normally need consent for any change, and some conservation areas restrict uPVC or new styles. Flats may also need the building owner's approval. We check the position for your property before quoting.
Is triple glazing worth paying extra for?
Triple glazing adds a third pane of glass, which cuts heat loss and outside noise further than standard double glazing. It typically adds around a third to the cost of the glass units and makes opening sashes heavier. It makes most sense on cold or noisy elevations, or in homes being upgraded to a high energy standard. For many houses, modern double glazing with a warm edge spacer gives most of the benefit for less money.
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.
Can you combine replacement windows with other work?
Yes. Because we manage several trades under one contract, we can plan replacement windows alongside other work on your Welwyn Garden City home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Do you cover Hatfield, Hertford and St Albans?
Yes. As well as Welwyn Garden City, we cover Hatfield, Hertford and St Albans 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.
Nearby towns
If your address falls within AL7 and AL8, we cover it. The same goes for neighbouring Hatfield, Hertford and St Albans, which we include alongside Welwyn Garden City when arranging surveys and quotes.

