Letchworth Garden City, Hertfordshire
Glazed rear extension in Letchworth Garden City
We plan and build glazed and glass-box rear extensions for homeowners in Letchworth Garden City. Full-height glass, slim frames and big rooflights for the most open rear room. Start with a free site visit, then a written price once the design is agreed.
Letchworth Garden City is covered from our Hertfordshire round, including SG5, SG6 and SG7. Glass-led rear extensions in Letchworth Garden City are planned around which way the garden faces, because that decides the glass specification.
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 Letchworth Garden City?
For Letchworth Garden City we work from the East of England rate: £2,970–£5,090 per square metre of new floor, including VAT, standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £35,500–£61,000 |
| 4 m wide × 6 m deep (24 m²) | £71,000–£122,000 |
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 Letchworth Garden City?
Planning for a glazed rear extension in Letchworth Garden City follows the English householder rules.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is 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 Letchworth Garden City like to extend?
Letchworth Garden City mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a glazed rear extension in Letchworth Garden City comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Letchworth Garden City
Close by, we work in Baldock, about 1.7 miles away, and Hitchin, about 3.2 miles away.
- Glazed rear extension in Baldock
- Glazed rear extension in Hitchin
- Glazed rear extension in Henlow
- Glazed rear extension in Stevenage
- Glazed rear extension in Biggleswade
Other work in Letchworth Garden City:
FAQ
Glazed rear extension questions in Letchworth Garden City
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
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.
Does glass need planning permission?
The same rules apply as any rear extension; glass does not change the depth or height limits.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
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.
Do I need planning permission for a rear extension in Letchworth Garden City?
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.