Glazed rear extension in Horsham

How much does a glazed rear extension cost in Horsham?

Guide prices for a glazed rear extension in Horsham start from our South East England rate of £3,140–£5,380 per square metre, including VAT. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.

Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.

Do you need planning permission for a glazed rear extension in Horsham?

Here is how the rules in England apply to a glazed rear extension in Horsham.

English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.

New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.

What are homes in Horsham like to extend?

Horsham has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.

How a glazed rear extension in Horsham comes together

1. Look round and measure

   A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.

2. Options and costs

   We draw layout options and price each one, so the budget shapes the design rather than surprising you later.

3. Approvals

   Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

4. Build and sign-off

   We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.

Glazed rear extensions near Horsham

We also build glazed and glass-box rear extensions in nearby Broadfield (5.8 miles) and Crawley (7.2 miles).

• Glazed rear extension in Broadfield
• Glazed rear extension in Crawley
• Glazed rear extension in Cranleigh
• Glazed rear extension in Horley
• Glazed rear extension in Hurstpierpoint

Other work in Horsham:

• Single-storey rear extension
• Two-storey rear extension
• Kitchen-diner rear extension
• Side return extension
• Wraparound extension
• Terraced house rear extension

All rear extensions in Horsham