Merton · SM4 · SW19 · SW20
Builders in Merton, SW19 and SM4
Wraparound extensions, rear extensions and open plan kitchens across Morden, Wimbledon, Raynes Park, Colliers Wood and Mitcham — a borough with two completely different sets of houses in it, which want completely different things.
What we built in SM4
A mid-terrace in Morden with a tired conservatory at the back. We took it off and extended the full width of the property to the rear, producing an open plan kitchen and dining room across the back of the house, and folded a ground floor WC into the design while the drainage was already open.
That WC is a drainage question before it is a layout question. It has to reach the existing soil stack with adequate fall, and that requirement usually determines where it can go long before anyone thinks about which way the door should swing. Decide it early and it lands somewhere sensible. Add it late and it ends up under the stairs at an awkward angle.
Daylight was handled with two large rooflights, a window over the garden and bi-fold doors. On a full-width rear extension the rooflights matter more than the doors — the doors light the last stretch of the room beautifully and do very little for the rest of it.
Two housing markets in one borough
Merton is really two places. Around Wimbledon, Raynes Park, South Wimbledon and Colliers Wood you get Victorian and Edwardian terraces with rear outriggers and side alleys — classic side return and L-shaped dormer territory, the same anatomy we work on daily in Wandsworth. Around Morden and Mitcham the stock shifts to interwar and postwar semis and terraces, generally on wider plots with longer gardens, alongside a good deal of ex-local-authority housing built to the same generous plot pattern.
That difference changes the right answer. On a Victorian terrace, the space you are missing is usually sideways: the alley beside the outrigger is doing nothing, and filling it squares off the ground floor. On a nineteen-thirties semi it is usually backwards, because the plot is deeper and the side access is often already reasonable, so pushing into the garden costs you less than you fear and gains a room of proper proportions.
There is a third category worth naming. Wimbledon Village and the streets climbing towards the common carry larger detached and semi-detached houses on substantial plots, where the constraint is rarely space and almost always the planning position.
Conservatories, and what is underneath them
Merton has a great many conservatories, most of them added in the eighties and nineties, most of them freezing for half the year and unusable for the other half, and most of them occupying the best aspect in the house. Replacing one is the most common enquiry we get from this part of London.
Be careful with the assumption that you can build on what is already there. Conservatory bases were designed to carry a lightweight glazed structure, not a fully insulated one with a solid roof and a floor level with the rest of the house. Work on the basis that the foundations are being redone, and treat it as good news if a survey says otherwise.
The other thing that changes is the regulations. A conservatory of modest size, separated from the house by external-quality doors, sits outside a good deal of the building regulations. The insulated room replacing it does not. It is habitable space, and it has to perform as habitable space in insulation, in structure, in ventilation and in how it joins the rest of the ground floor. That is why a replacement is a build rather than a swap, and why quotations that treat it as a swap are usually missing something.
One trip round the back, not two jobs a few years apart
On the Morden house we built a wraparound rather than a side return alone, and that is a decision worth putting to anyone in the Victorian half of the borough.
A wraparound combines the side infill and the rear extension into a single build. The groundwork, the scaffold, the party wall process, the structural design and the disruption are all shared once rather than gone through twice. If there is any prospect of eventually wanting both, doing them together is almost always the better decision — not because the build is smaller in absolute terms, but because doing it in two stages means going through the whole process twice, including living through it twice.
The counterweight is the garden. On a Morden or Mitcham plot with real depth, taking the full width and a decent projection still leaves a garden worth having. On a tighter Colliers Wood terrace it may not, and the honest answer there is a side return with a shallower rear.
Planning in Merton
Applications go through Merton Council. Many single-storey rear extensions fall under permitted development, with tighter rules for flats, for conservation areas and for listed buildings. Merton has several conservation areas, particularly around Wimbledon Village and parts of Merton Park, where the original garden-suburb layout, its boundary treatments and its building lines are protected in ways that catch people out. Check your specific address rather than the general rule.
Building regulations approval is needed either way, and a party wall agreement wherever you are building at a shared boundary. On a Morden semi that is usually one neighbour. On a Colliers Wood mid-terrace it is both, and the notice periods are fixed, so serve early rather than discovering a wait you had not planned for.
Common questions about building work in Merton
Do you work across Merton?
Yes. Home Constructive builds throughout Merton, including Wimbledon, Raynes Park, Colliers Wood, Mitcham and Morden. Most of our work in the borough sits in SW19 and SM4. If your address is just outside, ring us anyway and we will tell you plainly whether it is a job we should take.
What sort of houses do you work on in Merton?
Two kinds, roughly. Victorian and Edwardian terraces around Wimbledon and Raynes Park, and interwar semi-detached houses towards Morden and Mitcham. The terraces suit side return work; the semis usually have more garden and take a rear or wraparound extension well.
Do I need planning permission for an extension in Merton?
Often not. Single storey rear extensions on the interwar semis frequently sit inside permitted development, and so do many rear dormers. The Wimbledon conservation areas change that, and an Article 4 direction can remove rights that the rest of the street still has. We confirm it for your address before drawings.
How do I get a price for work in Merton?
It starts with a free site survey at the house. We look at the structure, the drainage and the services, tell you what the house will and will not allow, and price the work we have actually seen. Ring 07891 981021, Monday to Saturday, or send the address and what you are thinking of doing and we will arrange a time.
Book a free site survey in Merton
We will tell you whether your house wants to go out, sideways or both — and whether the conservatory base is worth anything or is coming out with the frame.
The survey costs nothing, and you will get a straight answer about what your property will take before you spend anything on drawings.
From the portfolio
Merton, SM4 · WraparoundGround floor wraparound extension