Kitchen Extension Builders in Sydenham (SE26)
Professional kitchen extension builders in Sydenham, South East London.
Why Choose All Well for Kitchen Extensions in Sydenham?
Sydenham's Victorian villas have some of the largest rear gardens in South East London, which means kitchen extensions here can be genuinely ambitious — 5-6 metre rear extensions with full-width glazing that open onto terraced gardens. The hillside setting means many properties have elevated rear aspects with beautiful views south over the trees, making the extension the best room in the house. We design the glazing layout to make the most of whatever view your property has.
Every project comes with a fixed-price contract, single project manager, and full certification including Building Control sign-off.
Kitchen Extensions for Sydenham Properties
Sydenham is known for its victorian villas, edwardian terraces, hillside properties. Our kitchen extensions services are tailored to these property types, ensuring results that complement the character of your home.
Postcodes we cover: SE26
Kitchen Extensions Tip for Sydenham Homeowners
The hillside topography in Sydenham creates interesting foundation challenges. Properties on the slope often need stepped foundations that follow the garden gradient, which costs more than flat-site foundations but is standard practice here. Some of the steeper gardens need retaining walls at the point where the extension meets the existing ground level. We price this based on the actual site conditions — a flat-site quote from a builder who hasn't visited won't be accurate for most Sydenham properties.
Three Sydenham kitchen extension patterns
Three patterns cover most of what we build in SE26. Deep rear extension on a Victorian villa is the signature Sydenham project. The large villas along Sydenham Road, Westwood Hill, Kirkdale, and the streets towards Sydenham Hill Wood typically have generous rear elevations and substantial gardens of 18-30 metres in depth. We extend 5-6 metres into the garden, take out the load-bearing wall between the kitchen and dining room with a 203x133 UB or 254x146 UB steel beam (depending on span and load), and finish with full-width sliders or bifolds opening onto a terraced patio. Cost is £55,000-£90,000 including stepped foundations, structural steel, glazing, electrics, plumbing, and finishes. Build time 12-16 weeks. The 5-6 metre projection typically goes through the Larger Home Extension prior approval process under Class A. Wraparound extension on an Edwardian terrace is the second pattern, common on the streets around Sydenham station and the wider Edwardian terraces near Mayow Park. Combines a side return infill of 1.0-1.5 metres with a 4-metre rear projection. Cost is £65,000-£100,000. Build time 14-16 weeks. Party wall agreement with the neighbouring property is required. Hillside rear extension with retaining walls is the third pattern, distinctive to Sydenham's steeper streets. Properties on the upper slopes around Sydenham Hill, Wells Park Road, and Westwood Park have rear gardens that drop noticeably from the house — sometimes 1.0-2.0 metres of fall over the first 4-5 metres. The new extension needs short reinforced concrete retaining walls at the rear and stepped foundations following the gradient. Cost is £60,000-£100,000 including the retaining wall work. Build time 14-16 weeks.
Hillside foundations, conservation areas, and tree-affected sites
Three Sydenham factors distinguish kitchen extensions here from flatter SE postcodes. Stepped foundations and retaining walls. The streets running up the Sydenham slope have rear gardens that drop noticeably from the house. Standard strip foundations to Building Regulations Part A don't work on slopes — we use stepped foundations following the ground profile or short reinforced concrete retaining walls to create a level base for the new extension floor. The structural engineer specifies the foundation design after a trial hole investigation. Adds £4,000-£8,000 to typical extension cost compared with a flat-site equivalent. The threshold detail at the new rear doors is designed so the extension floor sits level with the existing kitchen, with the patio dropping away to the original garden level via shallow steps or decking. Mixed clay and sandy subsoil. Sydenham sits on a transition between London Clay and the gravel-and-sand deposits running across the Sydenham ridge. Foundation depths vary across the borough — typically 1.0-1.2 metres on sandy ground, 1.2-1.5 metres on clay, deeper near mature trees on the upper streets. We dig a trial hole at the survey on every project where ground conditions aren't already known. Sydenham Hill and Jews Walk conservation areas. The Sydenham Hill conservation area covers the upper slopes including some of the largest Victorian villas. The smaller Jews Walk conservation area is centred south of Sydenham High Street. Within both, exterior front-facing changes need sympathetic design — front door changes, window replacement, and render colour need conservation review. Rear extensions are generally fine because they're not visible from the street. Most Sydenham streets are outside both conservation areas and have full permitted development rights. We check the boundary on the Lewisham planning portal at the survey before quoting.
Lewisham Council process and project management
Sydenham falls under Lewisham Council. Permitted development under Class A covers the standard 3-metre rear projection on a terrace and 4 metres on a semi or detached. The Larger Home Extension prior approval process covers 4-6 metre projections on terraces and 4-8 metres on semis or detached, with an 8-week neighbour consultation. Larger projects need full planning at £206. Lewisham typically determines applications in 8-10 weeks. We submit a Lawful Development Certificate (£103, 6-8 weeks at Lewisham) on permitted development projects for written confirmation, which protects the property at sale time. Lewisham has Article 4 directions in some Sydenham streets that remove specific permitted development rights. They mainly affect front-of-property changes (cladding, window replacement, front-facing alterations) and rarely affect rear extensions, but we verify the planning status of each property before quoting. A Sydenham kitchen extension involves 13-16 trades over 12-18 weeks: demolition, foundations and any retaining walls, drainage, structural steel, brick and block, roofing, glazing, plastering, electrics (NICEIC to BS 7671), plumbing, gas (Gas Safe), kitchen fitting, tiling, flooring, painting. We assign one project manager from survey through handover with photo updates throughout the build. Fixed-price contracts cover labour, materials, structural engineer calculations (£800-£1,500 for stepped foundation and retaining wall design), Building Control fees (£400-£700 at Lewisham), FENSA glazing registration, party wall surveyor coordination, trial hole investigation, conservation area applications where relevant, and the Lawful Development Certificate or planning fee. Building Control inspections happen at foundation, retaining wall, DPC, drainage, structural steel, insulation (Part L: U-value 0.18 W/m²K for new walls and roof), and completion. Glazing is FENSA-registered. Roof construction is warm-roof with 150mm PIR insulation and EPDM membrane. Roof lanterns from Korniche or Glazing Vision are standard. Hillside-aspect properties suit large roof lanterns positioned to capture afternoon light onto the new kitchen island. Our office on Limes Avenue is 10 minutes from any Sydenham property.
Kitchen Extensions in Sydenham: What's Included
Kitchen Extensions Pricing in Sydenham
£45,000 – £90,000
10–14 weeks | Fixed-price contracts | No hidden costs
What Our Customers Say
“All Well managed our project from start to finish. The fixed-price contract meant no surprises, and the result is stunning.”
Verified Customer
Sydenham
“Professional team, clear communication throughout. They handled everything including Building Control sign-off.”
Verified Customer
Sydenham
Frequently Asked Questions
- How much does a Sydenham kitchen extension cost?
- Deep rear extensions of 5-6 metres on Victorian villas (the signature Sydenham project) run £55,000-£90,000 including stepped foundations, structural steel, glazing, electrics, plumbing, and finishes. Wraparound extensions on Edwardian terraces run £65,000-£100,000. Hillside extensions with retaining walls run £60,000-£100,000. Stepped foundations or retaining walls on the steeper slopes add £4,000-£8,000 over a flat-site equivalent. Larger Home Extension prior approval (for 4-6 metre projections on terraces) adds 8 weeks lead time but no additional planning fee on top of the £103 application. Trial hole investigation adds £400-£800 where ground conditions aren't already known. Fixed-price contract before any work starts.
- Why do Sydenham hillside extensions cost more than flat-site equivalents?
- Two reasons. First, foundations: properties on the slope need stepped foundations following the ground profile or short reinforced concrete retaining walls to create a level base for the extension floor. Adds £4,000-£8,000 over a flat-site equivalent. The structural engineer specifies the design from trial hole data rather than a generic estimate. Second, threshold detail: where the rear garden drops 1.0-2.0 metres below the new extension floor, the patio or decking needs a graduated step-down rather than a flush threshold. Bifolds typically open onto a new patio at an intermediate level rather than directly onto the original garden. Both elements are standard on Sydenham hillside projects and built into the fixed-price contract.
- Are Sydenham conservation areas restrictive for kitchen extensions?
- Only on properties within the boundary. The Sydenham Hill conservation area covers the upper slopes including some of the largest Victorian villas. The smaller Jews Walk conservation area is centred south of Sydenham High Street. Within both, front-facing alterations need sympathetic design — Lewisham can refuse retrospective consent for inappropriate changes. Rear extensions are generally fine because they're not visible from the street. Most Sydenham streets are outside both areas and have full permitted development rights. We check the boundary and any Article 4 direction on the Lewisham planning portal at the survey before quoting any work that affects external elevations.
- Why hire All Well for a Sydenham kitchen extension?
- Three reasons. First, hillside experience: we know the Sydenham slope — which streets need stepped foundations, where retaining walls are required, how to design the threshold detail so the new extension floor sits level with the original kitchen. Second, full accreditation: NICEIC for electrical (BS 7671), FENSA for glazing, Gas Safe registered for boiler relocation, structural engineer calculations included for stepped and retaining-wall designs, and Building Control sign-off included on every project. Third, fixed-price contracts: the quote doesn't change unless the specification does, including stepped foundations, retaining walls, party wall surveyor fees, and any Larger Home Extension prior approval. 57 verified Google reviews averaging 4.5/5. Office on Limes Avenue, SE20.
Kitchen Extensions Near Sydenham
Get a Free Quote for Your Sydenham Kitchen Extensions
Fixed-price quote, no obligation. Call us or fill out our form.