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 Mill Hill?
In Mill Hill, an orangery typically costs £3,100–£4,400 per m² of floor area, including VAT at 20% (standard rate). For a typical 16 m² project that is roughly £49,500–£70,500. That range is adjusted for London, where domestic building work typically costs around 30% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (11 m²) | £34,000–£48,500 |
| Typical project (16 m²) | £49,500–£70,500 |
| Larger project (22 m²) | £68,000–£97,000 |
| Rate per m² | £3,100–£4,400 |
The biggest cost drivers are:
- Lantern size
- Amount and type of glazing
- Opening into the house
- Frame material and colour
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for an orangery in Mill Hill?
The approval route for Mill Hill 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
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:
- Building control sign-off where required
- Foundations and dwarf walls or piers
- Flooring and decoration options
- Design to suit the style of the house
- Roof lantern and glazed panels
- Insulated perimeter roof with internal pelmet
How long does it take?
Build time is typically 8 to 12 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Mill Hill
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
Our Mill Hill coverage includes postcode districts NW7, and we also work in nearby places such as Edgware, Hendon and Finchley.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about orangeries in Mill Hill
Can an orangery replace a conservatory?
Yes. We can remove an old conservatory and build an orangery on new or upgraded foundations.
How long does it take?
Typically 8 to 12 weeks on site once approvals are in place.
Do you build orangeries in Mill Hill?
Yes. We build orangeries across Mill Hill, including postcodes NW7. Every project starts with a free home visit.
How much does an orangery cost in Mill Hill?
In Mill Hill, an orangery typically costs £3,100–£4,400 per m² of floor area, including VAT at 20% (standard rate). A typical 16 m² project comes to roughly £49,500–£70,500. Your fixed price depends on the survey and drawings.
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.