What is an orangery?

An orangery is an extension with brick or block piers, large areas of glazing and a solid perimeter roof around a central roof lantern. It sits between a conservatory and a traditional extension: brighter than an extension, warmer and more private than a conservatory.
How much does an orangery cost in Windsor?
In Windsor, an orangery typically costs £2,700–£3,800 per m² of floor area, including VAT at 20% (standard rate). For a typical 16 m² project that is roughly £43,000–£61,000. Building costs in the South East run about 12% above the UK average, and the figures for Windsor are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (11 m²) | £29,500–£42,000 |
| Typical project (16 m²) | £43,000–£61,000 |
| Larger project (22 m²) | £59,500–£83,500 |
| Rate per m² | £2,700–£3,800 |
The biggest cost drivers are:
- Amount and type of glazing
- Opening into the house
- Lantern size
- Size and shape of the footprint
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for an orangery in Windsor?
The approval route for Windsor is set by planning law in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Electrics, heating and plastering
- Foundations and dwarf walls or piers
- Insulated perimeter roof with internal pelmet
- French, sliding or bifold doors
- Flooring and decoration options
- Design to suit the style of the house
How long does it take?
Allow 8 to 12 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Windsor
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
Our Windsor coverage includes postcode districts SL4, and we also work in nearby places such as Slough, Egham and Staines.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about orangeries in Windsor
Does an orangery need building regulations approval?
If it is open to the house or does not meet the conservatory exemption, yes. Most orangeries are treated as extensions and need building control approval, which we arrange.
How much does an orangery cost in Windsor?
In Windsor, an orangery typically costs £2,700–£3,800 per m² of floor area, including VAT at 20% (standard rate). A typical 16 m² project comes to roughly £43,000–£61,000. Your fixed price depends on the survey and drawings.
Who approves an orangery in Windsor?
Planning matters in Windsor go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How long does it take?
Typically 8 to 12 weeks on site once approvals are in place.
What is the difference between an orangery and a conservatory?
An orangery has a solid roof around a central lantern and more brickwork, while a conservatory is mostly glazed. Orangeries are usually warmer in winter and cooler in summer.
