Dartford wraparound extensions, designed and built
Our design and build teams take on wraparound extensions in Dartford, from the first measured survey through planning and building control to the finished room.
- Guide price in DartfordFrom £40,000 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsDA1, DA2, DA9

How much does a wraparound extension cost in Dartford?
These guide figures apply our South East England adjustment (×1.12) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Dartford: £2,240 to £4,140 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £40,000 – £48,500 | £46,000 – £58,500 | £58,000 – £75,000 |
| Medium L-shape 25 m² | £56,000 – £67,500 | £64,000 – £81,500 | £81,000 – £104,000 |
| Large L-shape 32 m² | £71,500 – £86,500 | £82,000 – £104,000 | £103,500 – £133,000 |
For a figure based on your own dimensions, use our guide-price tool.
Local to Dartford
Site visits are available across Dartford (DA1, DA2, DA9). The same team covers Swanley (4 miles), Gravesend (7 miles), Strood (12 miles), Sevenoaks (12 miles), all within easy reach.
Bexley, in Greater London, is roughly 3 miles from Dartford and also on our list. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Planning and approvals in Dartford
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Who a wraparound extension suits
- Semi-detached houses with a side passage
- Terraced houses that want the largest ground floor possible
- Families who want kitchen, dining and living in one space
The corner is where wraparounds succeed or fail. We usually use a single steel goalpost or a corner post hidden in a pier, and set the glazing so the new room reads as one space rather than two boxes.
What happens next
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Wraparound extension questions answered
Who do I contract with for a wraparound extension in Dartford?
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.
Do you cover all of Dartford?
Yes. We cover Dartford and the surrounding parts of Kent. Site visits are free and there is no obligation.
How long does a wraparound extension take to build in Dartford?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Will I need to move a drain?
Often. Side returns frequently contain a manhole or a shared drain. Building near or over a public sewer needs the water company’s consent in England and Wales, which we arrange.
Do wraparound extensions need planning permission?
Usually, yes. In England the side element counts as a side extension and the rear element as a rear extension, and the combination normally falls outside permitted development. A householder application costs £548 in England from 1 April 2026.
Book a free site visit in Dartford
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.