07834 989360 Mon–Fri, 8am–5pm - AboutServicesAreasOur WorkReviewsContact07834 989360Request an Estimate Home/ - Areas we cover/ - Builders in Kent Kent · Rated 5.0 on Google # House extensionsand new buildsacross Kent From our Sidcup office we deliver extensions, loft conversions, refurbishments and new build homes across Kent: with design coordination, planning, procurement, construction and supervision all managed under one contract. Request an estimate07834 989360 Written, itemised estimate after a survey, no obligation to proceed. 30 yearsof construction experience across the team CABE membersprincipals are members of the Chartered Association of Building Engineers 5.0 starsrated 5.0 from 14 Google reviews One point of contactdesign coordination, planning, procurement, build and supervision under one contract Building in Kent ## We work in Kent, and we know its houses Kent is our home county: our office sits at Onega House, 112 Main Road, Sidcup, DA14 6NE, on the London and Kent border, and we work outward from there across the north-west of the county and beyond where the project suits. Enquiries are handled Monday to Friday, 8am to 5pm, and site visits are arranged from that base. Kent covers a far wider range of property than any single town. We work on Victorian and Edwardian terraces in the older centres, inter-war and post-war suburban housing, larger detached homes with the garden depth for substantial wraparound extensions, converted and period cottages, and individual plots suitable for a new build home. That range is exactly why we survey and design each project from scratch rather than working from a template. Planning practice also differs across the county. Local authorities take different views on rear extension depth, roof form, dormer position and materials, and conservation areas and listed buildings appear throughout. We assess the planning route for your specific address before design work begins, so you know at the outset whether permitted development applies or a full application is needed. The work we are asked for most across Kent is single and double-storey extensions, loft conversions with rear dormers, whole-house refurbishment after a purchase, structural openings to create open-plan ground floors, garden rooms and home offices, and individual new build homes on infill and garden plots. Kent projects range from Victorian terraces to detached homes with room for a substantial wraparound or a new build plot. We assess the planning route for your specific address before any design work begins, so you know early whether permitted development applies. Every Kent project runs through the same five stages: design, planning and preparation, procurement, construction and project supervision, all managed under one contract by a team with 30 years of experience, with principals who are members of the Chartered Association of Building Engineers. You can request an estimate or read more about how we work. ## Get an estimate in Kent Send us the details and we'll be in touch during working hours, Mon–Fri, 8am–5pm. Services in Kent ## What we build in Kent ### Home Extensions Single-storey, double-storey and wraparound extensions, design coordinated and built by one team. Home extensions in Kent ### Loft Conversions Turn unused roof space into a bedroom, en-suite or office, structurally sound and building-control signed off. Loft conversions in Kent ### New Build Homes Individual new build homes delivered from design package through to completion. New build homes in Kent ### Full Refurbishments & Renovations Whole-house refurbishment, kitchens, bathrooms and period property renovation, managed end to end. Refurbishments & renovations in Kent ### Internal Alterations Knock-throughs, new openings, reconfigured layouts and structural steels installed safely. Internal alterations in Kent ### Outbuildings & Garden Rooms Insulated garden rooms, home offices, gyms and garages built to last all year. Outbuildings in Kent ### Architectural Drawings & Design Coordination Survey, concept, planning and construction drawings coordinated with our recommended architects, ready to build from. Drawings & design in Kent ### Structural Works Steels, foundations, load-bearing alterations and structural repairs. Structural works in Kent ### Carpentry & Joinery First and second fix carpentry, roof structures, staircases and fitted joinery. Carpentry in Kent ### Brickwork Extensions, garden walls, repointing and matched brickwork on period properties. Brickwork in Kent ### Roofing Pitched and flat roofing, dormers, leadwork and roof coverings on new and existing homes. Roofing in Kent ### Electrical, Plumbing & Gas Coordinated through vetted, accredited subcontractors: NICEIC/NAPIT registered electricians and Gas Safe engineers. Electrical & plumbing in Kent Why Ashcroft ## Why homeowners in Kent choose us ### A Kent-based team We are based at Onega House, 112 Main Road, Sidcup, DA14 6NE, and work across Kent from there. ### Turn-key delivery, one contract Design, planning and preparation, procurement, construction and project supervision are all managed by us, no need to appoint an architect or engineer separately. ### 30 years of experience The team carries 30 years of construction experience, across residential projects and some commercial work. ### CABE codes of practice Our principals are members of the Chartered Association of Building Engineers and work to its codes of practice and ethical standards. ### Rated 5.0 on Google 5.0 stars from 14 reviews, with clients citing clear communication and work delivered on time and to a high standard. ### Certification handled Electrical work by NICEIC or NAPIT registered subcontractors, gas by Gas Safe registered engineers, and building control managed from application to sign-off. Local property issues ## What we typically find on Kent properties ### Chalk, clay and variable ground Foundation design across Kent has to respond to what is actually under the site: shrinkable clay near mature trees, chalk in places, and made ground on former industrial or garden land. Depths are set from the survey, not from a standard detail. ### Solid-wall period property Older Kent houses with solid walls need breathable materials. Cement render and hard pointing trap moisture and spall the brick face, which is why lime-based mixes are usually correct on this stock. ### Conservation areas and listed buildings Materials, window detail and roof form come under much closer scrutiny in protected areas, and internal work to a listed building normally needs consent. This gets confirmed before design, not after. ### Exposure on open sites Properties on open or elevated Kent sites take more weather. Pointing, flashings, verge and eaves detailing all wear faster there, and specification should account for it rather than assume sheltered conditions. None of this is unusual, and none of it is a reason not to build. It is the reason we survey before we design and design before we price, so what turns up in Kent is in the estimate rather than in a mid-build conversation about extra cost. How it works ## Five stages, all managed under one contract - 01 ### Design We take your brief, survey the property and coordinate the drawings and design package with our recommended architects and engineers, so you have no separate consultants to find or brief. - 02 ### Planning & preparation Applications, building control and the programme of works are prepared and coordinated before anyone lifts a tool. - 03 ### Procurement Materials and vetted trades are secured against a fixed scope, so the build starts with everything in place. - 04 ### Construction Your build is delivered by skilled tradesmen working to the agreed drawings, programme and standard. - 05 ### Project supervision A named point of contact supervises the site, handles building control and keeps you updated to completion. Kent questions ## Frequently asked questions Which parts of Kent do you cover?+We work across Kent from our Sidcup office, with most projects in the north-west of the county including Dartford, Crayford, Bexley and the surrounding areas. Send us your postcode and we will confirm. How quickly can you get to a site in Kent?+Surveys and site visits are arranged during working hours, Monday to Friday, 8am to 5pm, from our base at Onega House, 112 Main Road, Sidcup. What do extensions cost in Kent?+The drivers are size, ground conditions, structural work, glazing and internal specification. We survey the property and issue a written estimate with the scope broken down item by item. Do you build new homes in Kent?+Yes. We deliver individual new build homes from design and planning through groundworks, structure, envelope and finishes, with site supervision throughout. Can you work from our architect's drawings?+Yes: we can build to an existing approved package, or coordinate the drawings with our recommended architects if you would rather keep everything under one contract. Do you take on commercial projects in Kent?+Our focus is residential, and we do take on some commercial work. Send us the details and we will tell you straight away whether it suits us. Do you offer an emergency service?+No. We are a design-and-build contractor delivering planned projects rather than an emergency repair service. Which nearby areas do you also cover?+Dartford, Crayford, Sidcup, Bexley, Bexleyheath, Welling, Blackfen and South East London. Rated 5.0 from 14 reviews ## What our clients say “Adam, Robbie and the team were fantastic delivering our kitchen extension and bathroom, great communication throughout and happy to adjust the design as we went.”Peter TingayKitchen extension & bathroom“Adam and Rob's team did an amazing job on our extension, from start to finish they made the process straightforward and painless.”Keith WeirHome extension“Professional, friendly and did a wonderful job creating a new opening between rooms in our Victorian home. Adam communicated clearly throughout. Highly recommend.”Holly MillsStructural opening Coverage ## Areas near Kent we also serve Builders in SidcupBuilders in BexleyheathBuilders in DartfordBuilders in CrayfordAll areas we cover Alongside Kent we work across Dartford, Sidcup, Crayford, Bexleyheath and the wider Kent and South East London area from our office at Onega House, 112 Main Road, Sidcup, Kent, DA14 6NE. If you are not sure whether your postcode is covered, contact our Sidcup builders and we will tell you straight away. You can also see examples of our work or start from our home page. ## Planning work in Kent? Tell us about the property and what you want to achieve, or call 07834 989360. Request an estimate07834 989360 Extension, loft conversion and refurbishment specialists based in Sidcup, working across London, Kent and the surrounding areas. 5.0 from 14 Google reviews Facebook - Instagram ## Services Home extensions - Loft conversions - New build homes - Refurbishments & renovations - Internal alterations - Outbuildings - Drawings & design - Structural works ## Areas we cover - Bexley - Kent - South East London - Welling - Sidcup - Bexleyheath - Dartford - Crayford - Blackfen ## Get in touch - 07834 989360 - info@ashcroftconstructiongroupltd.co.uk - Onega House, 112 Main Road, Sidcup, Kent, DA14 6NEMonday8am – 5pm Tuesday8am – 5pm Wednesday8am – 5pm Thursday8am – 5pm Friday8am – 5pm SaturdayClosed SundayClosed © 2026 Ashcroft Construction Group Ltd. All rights reserved. ReviewsCookie policyPrivacy policyTerms & conditionsPrincipals are members of the Chartered Association of Building Engineers (CABE). Call nowGet estimate We use essential cookies to run this site, plus cookies from our enquiry form, chat and review widgets. Cookie policy RejectAccept