Conservatory replacement extensions across Harpenden
Planning a conservatory replacement in Harpenden? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in HarpendenFrom £21,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsAL5
What we take care of
- New or upgraded foundations
- Glazing and doors to suit the new room
- Insulated walls and roof to current regulations
- Removal and disposal of the old conservatory
Do I need planning permission in Harpenden?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
How much does a conservatory replacement cost in Harpenden?
These guide figures apply our East of England adjustment (×1.06) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Harpenden: £1,960 to £3,710 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £21,000 – £25,500 | £22,500 – £29,500 | £29,000 – £37,500 |
| 3.5 m × 4 m 14 m² | £27,000 – £33,000 | £31,500 – £41,000 | £40,500 – £52,000 |
| 4 m × 5 m 20 m² | £39,000 – £47,000 | £45,500 – £58,500 | £58,000 – £74,500 |
Includes removal of the old conservatory. Reusing existing foundations is only possible after investigation.
For a figure based on your own dimensions, use our guide-price tool.
Local to Harpenden
Postcode districts we cover around Harpenden include AL5. Nearby, we also take on projects in St Albans (5 miles), Hemel Hempstead (6 miles), Welwyn Garden City (6 miles), Hatfield (7 miles).
For homes towards Bedfordshire, Luton is around 5 miles away. Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Harpenden home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about conservatory replacements
Do you cover all of Harpenden?
Yes. We cover Harpenden and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
Who do I contract with for a conservatory replacement in Harpenden?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours in Harpenden be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Is it worth replacing a conservatory with an extension?
If the conservatory is unusable for much of the year, usually yes. A solid extension gives a heated room that counts as proper living space. Our guide range is about £1,960 to £3,710 per m² including VAT, including removal.
Can I keep the existing base?
Sometimes, but conservatory bases are often too shallow for solid walls. Trial holes tell us before we confirm the price.
Book a free site visit in Harpenden
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.