House extensions in Croydon
More space, more light, and a ground floor that finally works the way you live. Designed and built by one local team.
Building extensions in Croydon since 2003
Most families who call us about an extension aren’t really after more square metres. They want a kitchen they can all sit in, somewhere to work from home that isn’t the end of the dining table, or a downstairs loo so the morning queue stops. A good extension sorts that out and lets you stay in the area you love.
We’ve been building house extensions in Croydon for more than twenty years, on everything from Victorian terraces in South Norwood to big detached houses in Sanderstead. We handle the whole job: design, planning, building control, the build itself and the snag list at the end.
Types of extension we build
Single-storey rear extensions
The most popular choice, usually built to create an open-plan kitchen-diner with bi-folds or sliding doors onto the garden. Rooflights or a lantern stop the middle of the room going dark.
Side-return extensions
Perfect for terraced and some semi-detached houses with an unused alley down the side. Filling it in can widen a narrow galley kitchen into a proper family room.
Wrap-around extensions
A side return and rear extension built as one L-shaped space. It’s the biggest single-storey option and gives a very generous open-plan layout.
Two-storey extensions
Extra living space downstairs and an extra bedroom or bathroom above. Because the foundations and roof serve two floors, it’s usually the best value for the space you gain. The photos below follow one of our two-storey builds from groundwork to finish.
How we build an extension
We sequence every job carefully, because getting the order of trades wrong is where time and money disappear. Foundations go in first, dug to the depth building control signs off, with deeper footings or an anti-heave system on clay near trees. Then the floor, the cavity walls and the steels, then the roof. First-fix electrics and plumbing go in while the walls are open, and the plasterer only arrives once the building is watertight.
Throughout the job Baz is on site, building control inspects at each stage, and you get regular updates so you always know what’s next. At the end we walk round together and work through a snag list until you’re happy.
What it costs
Every extension is different, so we don’t guess over the phone. The size, the glazing, the kitchen, the ground conditions and the access all make a big difference. After a free survey you get a fixed-price, itemised quote. Our guide on what affects the cost of an extension explains more.
A two-storey extension, from groundwork to finish
One of our builds start to finish: screw-pile foundations, ground beams, brickwork, roof and the finished rooms inside.
More of our extensions
Single-storey, side-return and two-storey extensions across Croydon and South London.
Recent projects like this
Extension · Shirley, Croydon CR0Rear kitchen extension on Chaffinch Avenue, Shirley
A Croydon family swapped their conservatory for a proper kitchen-diner, and had it finished in eight weeks.
See the project →
Extension · Lee SE12Rear extension and ground-floor refit on Horn Park Lane, SE12
Swapping a tired conservatory for a 40m² kitchen extension, on clay soil that was already lifting the house.
See the project →
Extension · Chislehurst BR7Rear extension and ground-floor refurbishment on Oakdene Avenue
A small extension that changed the whole ground floor, finished in 12 weeks.
See the project →
What our customers say
We’re rated 4.8 out of 5 on Google from 24 reviews, and most of our work comes from recommendations. A few words from our customers:
“Superb job from start to finish! Baz and his team constructed a new extention with kitchen for us and couldnt have been more helpful.. nothing was too much trouble.”
Lianne Edwards · Google review “Work was carried out to an extremly high standard we couldnt be more happy!”
Google review “We have no hesitation in recommending Baz and Smiley Building Services.”
Google review “Now that the dust has settled and the decorating completed, we would like to take a moment to thank you and the team that carried out all the work to create our extension into a delightful new room. Throughout the program, the timeliness and courteous behaviour of the various tradesmen gave us confidence of a successful completion to a high standard of workmanship. The structural design allowed an impressive use of the available space to give light and airy room together.”
Mr Darren, SW20 · Customer testimonial “We just felt we had to write to you to say ‘thank you’ for doing such a wonderful job on our extension. Smiley and Chris were brilliant, from start to finish; everybody involved was extremely professional and very efficient. The extra space and en-suite is looking far better than we ever could have imagined. We would both certainly recommend Smiley Building Services to anybody in the future.”
Mrs Jasmin, CR1 · Customer testimonial “Thank you so much to Smiley Building Services for a fantastic Extension. We are very impressed with the service we received, of course a big thank you to Smiley and Chriss for their hard work. Smiley was especially helpful and always discussed his plans with us, so we were always informed as to the progress of the room. He was very reliable and very sweet. We have no hesitation in recommending you to our friends. Thank you once again and happy new year.”
Mrs Gabre, CR5 · Customer testimonial
Frequently asked questions
Do I need planning permission for a single-storey extension?
Often not. Many single-storey rear extensions fall under permitted development if they stay within the size and height limits and your house still has those rights. Side extensions, two-storey extensions and anything in a conservation area usually need a planning application. We check before anything is designed.
How long does an extension take to build?
A single-storey extension usually takes 8 to 12 weeks on site and a two-storey extension 12 to 16 weeks, depending on size, ground conditions and the fit-out. Our Chaffinch Avenue kitchen extension took eight weeks; Oakdene Avenue, with a full ground-floor refurbishment, took twelve.
Can you do the drawings?
Yes. We can arrange the drawings, structural calculations, planning or Lawful Development Certificate and building regulations as part of a design-and-build service. If you already have plans, we’ll build from yours.
Can I live at home during the build?
In most cases, yes. We build the new structure first and keep the house sealed off from the works until the last moment, when we break through into the extension.
What about my neighbours?
If you share a wall or we’re digging close to their foundations, the Party Wall Act applies and notices need serving. We’ll make sure that’s done in good time, and we always recommend a friendly chat with them early on.
Book a free site survey
Tell us a bit about the job and Baz will give you a ring to arrange a visit. There’s no charge for the survey and no pressure afterwards. You’ll get a fixed-price, itemised written quote, so you know exactly where you stand.
- Call or text07786 254637
- Emailinfo@smileybuildingservices.co.uk
- Opening hoursMon–Fri 8am–6pm, Sat 9am–1pm