Home Extension Builders in Kensington
Kensington W8 extension and lower-ground works to a high specification, delivered by Buildaway with the engineering and joinery such homes warrant.
Your Local Home Extension
Specialists in Kensington
Searching for extension specialists in Kensington (W8)? Buildaway works across W8 -
the stucco terraces off Kensington High Street and Kensington Church Street, the
homes near Kensington Palace and Kensington Gardens, the Phillimore estate, and the
properties toward Holland Park and Earl's Court.
Kensington extension and lower-ground works are delivered to a high specification by
Buildaway, with the engineering and joinery such homes warrant. In W8 the scheme is
almost always downward - basement excavation, underpinning and structural
waterproofing - which makes the engineering and the party-wall process the real
project. Buildaway handles consents, structure and finish under one Kensington
contract, with our own trades delivering the parts that matter most.
Our Home Extension Packages in Kensington
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 Kensington Homeowners Choose Buildaway
Skilled local teams with deep knowledge of W8 and surrounding areas
Based in your area with local expertise and reputation.
Bespoke extension designs ideal for historic Georgian homes, riverside apartments, and contemporary residences
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.
Complete project management ensuring a seamless, stress-free experience
Meticulous craftsmanship in every aspect of your extension.
Trusted reputation with successful installations near Kensington Palace, Holland Park, and the Natural History Museum
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 Kensington and surrounding areas, helping customers plan projects with clarity before starting work.
Home Extension Cost in Kensington
A local cost guide written specifically for Kensington 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.
“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
“A great transformation of my bathroom into something modern and sleek. Cormac was professional to work with from the start and was very helpful in taking my ideas and sourcing products to fit the space and look aesthetically pleasing. I felt confident in working with the company as I could ask questions and I was also pleased to get suggestions and ideas…”
Vera Jajechnyk
“We had an excellent experience working with Buildaway. Cormac was incredibly easy to work with, and gave helpful advice. The finished job was neat, professional and completed efficiently. We'd definitely recommend and would use them again!”
Roisin Lawrence
“They were also very professional day to day - always tidy, and cleaned up really thoroughly when taking away all rubbish at the end. They stuck to the agreed timelines, and pricing was transparent throughout, with clear communication on any issues as they arose. Overall, I’m really pleased with the result and felt I could trust them throughout. I wouldn’t hesitate to recommend them…”
Sean Kelleher
“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
“The quality of the work, their high standards, and their professionalism, along with effective and proactive communication made a refreshing change from the builders I have used in the past. Even when we changed our minds and ideas during the job Cormac’s patience and support emphasised that he wanted to make sure that the finished product was exactly what we wanted…”
Michael Marks
Frequently Asked Questions
Your questions about home extensions in Kensington, answered.
How much does a home extension cost in Kensington?
Extension costs in Kensington are driven by groundwork, structure and glazing more than floor area alone. Across W8, expect about £3,300–£4,400 for a single-storey rear, £4,400–£5,800 for wrap-around, £82,500–£110,000 for double-storey. Buildaway itemises groundwork, steels, services and finishes separately so the trade-offs are visible.
How long does a home extension take in Kensington?
Allow roughly 12–20 weeks of build in Kensington, depending on scheme. The programme most people forget is before that: design, the Royal Borough of Kensington & Chelsea approval and party-wall awards can add 3–4 months to a W8 project. Buildaway runs those in parallel and gives you a realistic combined timeline up front.
Do I need planning permission for an extension in Kensington?
Assume it may. Kensington extensions frequently run into conservation-area policy or listed-building consent, and W8 flats cannot use permitted development regardless. Buildaway resolves the the Royal Borough of Kensington & Chelsea position first, because it determines what is worth drawing.
What types of extension do you offer in Kensington?
Rear, side-return, wrap-around, double-storey and lower-ground - Buildaway delivers all of them in Kensington. Terraces around Kensington Church Street and Holland Park usually point to a side-return; where outward space is limited in W8, going down or reconfiguring inside often makes better sense. We advise from survey.
Do Buildaway handle both design and construction for Kensington extensions?
Yes - design, planning and construction under one Buildaway contract in Kensington. That single accountability is the main reason our W8 extensions finish on the dates we committed to.
Are your extension specialists local to Kensington?
Buildaway covers Kensington and the wider W8 area year-round. Having extended this housing stock around Kensington Church Street and Holland Park repeatedly, we know its constraints before the survey - and we are nearby well after handover.
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We Serve Kensington and Surrounding Areas
Find us in the heart of Kensington. We are proud to serve our local community.
Nearby Areas We Serve
Below are some of the local areas where you can find Buildaway transforming homes.
Ready to Transform Your Extension in Kensington?
Buildaway consistently transforms Kensington extensions into luxurious, elegant, and highly functional spaces, enhancing both comfort and property value.