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.
Getting replacement windows right in Horsham starts with understanding the house you already have: its age, how it was built and what has been altered over the years. We survey first, then commit on paper to a price that holds as long as the scope stays the same. Across the South East, guide prices run at £5,000–£10,000 including VAT, and homes in Crawley, Horley and Haywards Heath are covered too.
- Guide price
- £5,000–£10,000 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- RH12
- Planning rules
- England
- Local area
- West Sussex
- Survey
- Free, with a written quote
How much do replacement windows cost in Horsham?
These are guide costs, not quotes. For replacement windows in Horsham the range is £5,000–£10,000, VAT included, reflecting prices in the South East that are about 12% 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 Horsham |
|---|---|---|
| One to three windows | Replacing a few problem windows, such as a bay or a rotten kitchen window, in uPVC. | £800–£3,400 |
| Whole house in uPVC | Eight to ten standard uPVC casement windows on a typical 3-bed semi, fitted and finished. | £5,000–£8,400 |
| Whole house in aluminium or flush sash | Premium frames, colours or period styles across a typical 3-bed home. | £8,400–£15,500 |
What moves the price up or down:
- Number and size of windows, including bays and large picture windows
- Frame material, colour and finish, inside and out
- Glazing type: double, triple, acoustic, obscure or toughened
- Window style, such as sash, flush sash or tilt-and-turn
What do you get?
- Measured survey of every opening, with sizes checked before manufacture
- Double-glazed units as standard, with triple glazing as an option
- Fixings, packers, foam and weather seals to suit your wall type
- New internal trims, external cills and neat sealant finishing
- Trickle vents, escape hinges and safety glass where regulations require
- Building regulations sign-off arranged and paperwork handed over
Local housing and replacement windows
Chichester has Georgian brick streets, Downland villages use flint and brick, and Horsham stone slabs cover some older roofs. Worthing and Bognor Regis have interwar and post-war bungalows and semis, Crawley was planned as a post-war new town, and Wealden villages to the north feature tile-hanging and timber framing.
Bungalows commonly suit loft conversions and extensions; new-town homes often take window, roofline and cladding renewal. Flint and stone properties need lime repointing, and coastal homes may need external decorating more often.
For replacement windows in Horsham, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Do you need permission in Horsham?
Homes in Horsham come under the regulations for England, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
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
Free site survey
First, someone visits your home in Horsham to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Your fixed price
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.
Getting ready
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Build and hand over
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
What you can expect from us
Common questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from replacement windows, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
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.
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.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
How much do replacement windows cost?
Replacement windows for a typical 3-bed semi cost £5,000–£10,000, depending on the number of windows, frame material and glazing. A single standard uPVC casement usually works out at roughly £500–£950 fitted, while aluminium, flush sash and sliding sash styles cost more. Bays, large panes and upstairs access add to the price. We measure every opening during the survey and give you a fixed price for the agreed specification.
Near Horsham
Live in Horsham? Our coverage takes in the RH12 postcode areas and reaches out to Crawley, Horley and Haywards Heath, so homes on the outskirts and in the next town along are included.

