Home Extension Builders in Forest Hill
Forest Hill SE23 home extension from Buildaway - design, planning, groundwork, structure and finish, all delivered by one accountable team.
Your Local Home Extension
Specialists in Forest Hill
Looking for home extension builders in Forest Hill (SE23)? Buildaway extends homes
throughout SE23 - the Victorian and Edwardian houses off Dartmouth Road and London
Road, the properties near Forest Hill station and the Horniman Museum, and the
streets toward Honor Oak Park and Sydenham.
Forest Hill home extension from Buildaway covers design, planning, groundwork,
structure and finish, all delivered by one accountable team. SE23's hillside plots
mean levels, retaining and drainage frequently drive the cost more than the floor
area does, so Buildaway surveys the ground before quoting the build. Our Forest Hill
extension team handles the planning application, building control and construction,
with the full scope itemised before work starts.
Our Home Extension Packages in Forest Hill
Single-Storey Rear Extension
Ideal for expanding your living space. Includes structural survey, architectural drawings, groundworks and foundations, brickwork and roofing, bi-fold or sliding doors, heating installation, building regulation approval.
Side Return Extension (Most Popular)
Complete kitchen and living area transformation. Includes structural assessment, full groundworks, steelwork if required, brickwork and matching materials, glazing and doors, full insulation, electrics upgrade, flooring, building regulation approval, waste removal.
Double-Storey Extension
For those seeking maximum space addition. Includes architectural design, full structural alterations, steelwork and foundations, bespoke staircase, multiple room creation, bathroom or en-suite option, planning and building regulation handling.
Why Forest Hill Homeowners Choose Buildaway
Specialist installation teams experienced with SE23 and local Lewisham properties
Based in your area with local expertise and reputation.
Bespoke extension designs for Victorian terraces, Edwardian townhomes, and detached properties
We handle everything so you don't have to worry.
Transparent and honest pricing with no hidden fees or unexpected charges.
Clear upfront pricing with no surprises along the way.
Discreet, stress-free project management with minimal disruption
Meticulous craftsmanship in every aspect of your extension.
Reputation built working near Forest Hill station, Horniman Museum, and Dartmouth Road
Professional consultation and detailed quotes at no cost.
What's Included in Your Home Extensions Services
Everything you need for a seamless, stress-free home extension from structure to finish.
Full groundworks and structural build
Complete groundwork preparation and structural construction services.
Plumbing, electrics, and heating integration
Professional installation of all mechanical and electrical systems.
Roofing, windows, and external finish
Complete roofing, window installation and exterior finishing.
Plastering, flooring, and decorating
Professional plastering, flooring and decorating services.
Interior fit-out and finishing
Complete interior fit-out and professional finishing touches.
Project management and schedule control
Professional project management and timeline control throughout.
Latest Home Extension Insights
We publish detailed home extension guides and cost insights for homeowners across Forest Hill and surrounding areas, helping customers plan projects with clarity before starting work.
Home Extension Cost in Forest Hill
A local cost guide written specifically for Forest Hill homeowners, with real figures for the area.
Home Extensions London: The Complete 2026 Guide
Everything from feasibility and planning to structure, cost and programme for a London extension.
Single-Storey Rear Extension Cost London
A realistic cost breakdown for the most common extension in London, with the variables that move it.
What Our Clients Say
Real reviews from our satisfied customers.
“The team turned up when they said they would and kept the house tidy each day, which made a big difference while we were living in the property during the works. The quality of the finish is excellent. The bathroom looks fantastic and the bedrooms feel completely refreshed. We wouldn’t hesitate to recommend Cormac and the Buildaway team…”
Helen Sivyer
“Greg's attention to detail and dedication elevated both the experience and the result - he certainly knows his way around a tile. In addition to the bathroom refit, Cormac replaced all the plastic switches, sockets and pull-cords in the house with brushed brass. Highly recommended and will certainly work with the Buildaway team again…”
Kane Dempsey
“It was an absolute pleasure working with Cormac and the Buildaway team. Greg is an absolute star. Cormac’s communication and advice was excellent, and the organisation and sourcing of additional materials was brilliant. A truly great team, I would thoroughly recommend Buildaway if you are after a stress free and top quality renovation.”
Sim Lewis
“From my first contact with Cormac, I was in good hands. His team turned my vision into reality, communicating with me every step of the way and offered helpful suggestions which turned my bathroom into an oasis. I could not be happier and would highly recommend their services. Thank you to the team of Buildaway Construction Ltd…”
Jackie Brown
“I am extremely impressed, happy and proud of what he and his team of Archie, Ben and Danny delivered. They all went beyond and far, I am very grateful for what they have done for me. I would 100% recommend Buildaway for any building, renovation etc - an excellent team with a good rapport, team spirit and working harmoniously together. Thank you Team Buildaway…”
Betty Lwanga
“From scoping to completion, Cormac was always very responsive, answering any questions we had on product selection and helped us source the products to get the best price. His team worked extremely hard and a big shoutout to Greg for his attention to detail! We couldn’t be happier with the results and would highly recommend Buildaway for any building project in the future…”
Georgina Ehmcke
Frequently Asked Questions
Your questions about home extensions in Forest Hill, answered.
How much does a home extension cost in Forest Hill?
As a guide, a home extension in Forest Hill (SE23) runs roughly £2,400–£3,200 for a single-storey rear, £3,200–£4,400 for a larger or wrap-around scheme, and £60,000–£80,000 for double-storey work. UK build costs sit around £1,800–£3,000 per m², and London consistently lands at the upper end. Buildaway fixes your figure in a written quote after survey.
How long does a home extension take in Forest Hill?
Twelve to twenty weeks on site for Forest Hill, scheme depending. The build is the predictable part; Lewisham Council determination and party-wall awards are what stretch SE23 projects. Buildaway handles both alongside design so the dates hold.
Do I need planning permission for an extension in Forest Hill?
It depends on your SE23 property. Permitted development covers a good number of Forest Hill rear extensions, but if you are listed, in a conservation area, or leasehold, the answer changes and Lewisham Council consent is needed. Buildaway confirms what is achievable at feasibility rather than designing something that gets refused.
What types of extension do you offer in Forest Hill?
Buildaway builds rear, side-return, wrap-around, double-storey and lower-ground extensions across Forest Hill. Which suits your SE23 home depends on the plot, the boundary and what Lewisham Council will accept. Around Dartmouth Road and Honor Oak Park the side-return infill is often the highest-value option. Buildaway surveys before recommending.
Do Buildaway handle both design and construction for Forest Hill extensions?
Both, on one contract. For Forest Hill clients Buildaway handles drawings, structural engineering, consents and construction. Splitting design from build is where SE23 extension projects most often lose money, because the gap between them is nobody's problem until it is yours.
Are your extension specialists local to Forest Hill?
Buildaway covers Forest Hill and the wider SE23 area year-round. Having extended this housing stock around Dartmouth Road and Honor Oak Park repeatedly, we know its constraints before the survey - and we are nearby well after handover.
Get Your Free Quote
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We Serve Forest Hill and Surrounding Areas
Find us in the heart of Forest Hill. We are proud to serve our local community.
Ready to Transform Your Extension in Forest Hill?
We’ve transformed extensions in Victorian terraces, Edwardian townhomes, and large family homes throughout Forest Hill always delivering results built to last.