Henley-on-Thames, Oxfordshire
Glazed rear extension in Henley-on-Thames
Full-height glass, slim frames and big rooflights for the most open rear room. If you live in Henley-on-Thames and want to know what a glazed rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Henley-on-Thames and its postcode districts RG9 are part of our Oxfordshire coverage. A wide sliding door with one long rooflight, rather than a fully glazed roof, keeps a glass-led extension usable in summer.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a glazed rear extension cost in Henley-on-Thames?
A glazed rear extension in Henley-on-Thames is priced at £3,140–£5,380 per square metre including VAT as a guide, before kitchen fit-out and fees. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £37,500–£64,500 |
| 4 m wide × 6 m deep (24 m²) | £75,500–£129,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a glazed rear extension in Henley-on-Thames?
Planning for a glazed rear extension in Henley-on-Thames follows the English householder rules.
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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Henley-on-Thames like to extend?
Henley-on-Thames 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 Henley-on-Thames comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Glazed rear extensions near Henley-on-Thames
From Henley-on-Thames, the nearest places we also cover are Marlow (6.0 miles) and Reading (6.1 miles).
- Glazed rear extension in Marlow
- Glazed rear extension in Reading
- Glazed rear extension in Lower Earley
- Glazed rear extension in Maidenhead
- Glazed rear extension in Wokingham
Other work in Henley-on-Thames:
FAQ
Glazed rear extension questions in Henley-on-Thames
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Is the site visit in Henley-on-Thames free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Is a glass box a conservatory?
No. It is built to Building Regulations as part of the house, with insulated floor and roof, so it is usable all year.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need planning permission for a rear extension in Henley-on-Thames?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.