Central London · SW3 · SW5 · SW7 · SW10
Extensions in Kensington and Chelsea
The Smart Solution for Extensions. Family-run since 2008, working across Kensington and Chelsea and all 32 London boroughs.
Extension + loft, North Finchley
Rear extension and loft conversion in London stock brick with French doors, North FinchleyExtensions for Kensington and Chelsea homes
From the installation of steel beams and waste pipes to double glazing, we build extensions that clear building control first time. Most London extensions live or die on two questions asked early: does it fall under permitted development or need a full application, and is a Party Wall Award required. We answer both before you commit, in writing.
Stucco-fronted Georgian and Victorian terraces of exceptional value, almost entirely within conservation areas and with a high proportion of listed buildings. Basement works are subject to some of the strictest controls in the country.
That housing mix matters more than it sounds. It determines whether your extensions is a straightforward job or a structural one — how the loads transfer, whether a Party Wall Award is likely, and what the council will accept on the elevation. We survey before we price, so the number you get reflects your actual house rather than an average one.
Included as standard
- Feasibility check: permitted development vs. full planning
- Architectural drawings and planning submission
- Structural engineer's calculations and building control
- Party Wall Act notices, surveys and awards
- Foundations, drainage diversion and groundworks
- Brickwork matched to existing, steelwork and roofing
- Double glazing, bi-folds and rooflights
- Electrics, plumbing, heating and underfloor heating
- Plastering, screeding, flooring and decoration
- Building control sign-off and completion certificate
- Timescale
- 8–16 weeks on site
- Planning authority
- Royal Borough of Kensington and Chelsea
- Postcodes
- SW3, SW5, SW7, SW10
- Housing stock
- Mainly flats
What Kensington and Chelsea housing means for the structure
This matters more here than almost anywhere else in London: flats and maisonettes have no permitted development rights at all. Any external extension needs a full planning application, and separately it needs your freeholder's written consent under the lease. A ground-floor flat with a demised garden is the realistic case for a rear extension, and it turns on whether the extension can be built without relying on the structure above.
Planning and building control for extensions
A single-storey rear extension can often be built under permitted development rather than a full planning application: up to 3m deep on a terraced or semi-detached house, or 4m on a detached one, with a maximum height of 4m. Where it sits within two metres of a boundary, the eaves cannot exceed 3m.
The Larger Home Extension scheme doubles those depths — to 6m and 8m — but it is not automatic. It requires a prior approval application, and the council notifies your adjoining neighbours; if one objects within the consultation period, the council decides on the impact to their amenity.
Permitted development rights do not apply to flats or maisonettes at all, and they are removed or restricted in conservation areas and wherever an Article 4 direction is in force. That is the first thing we check, because it changes both the programme and the cost.
Whichever route the permission takes, the build itself is governed by the Building Regulations — Part A for structure, Part L for insulation and airtightness, and Part K where stairs or level changes are involved. Building control inspects at set stages, including before foundations are covered.
Those are the national rules. In Kensington and Chelsea they are administered by Royal Borough of Kensington and Chelsea, and they can be tightened locally by a conservation area or an Article 4 direction covering your street. We confirm the position for your address in writing before you commit to anything.
Working in Kensington and Chelsea
We are based in Chadwell Heath, RM6. Kensington and Chelsea is a regular run for us, and we resource jobs there properly rather than stretching a crew across the city. Scaffolding licences, skip permits and highway licences are all applied for in our name as part of the contract, because they have to be — they are the contractor's responsibility, not yours.
Access shapes the programme in London more than anywhere else. Narrow streets, controlled parking and shared alleys all affect how materials get in and waste gets out, and we plan for it at survey stage rather than discovering it in week two. Where a job needs a wait-and-load skip or a grab lorry instead of a standing skip, we say so in the quote.
You get a named project manager for the duration — Jagpreet (Sandeep) or Simarjit (Sonu) depending on where the job sits — and you pay in arrears of work completed rather than handing over a deposit and hoping.
Our work
Extensions we have completed
Our own photographs, not stock images. Ask and we will send you jobs closest to your Kensington and Chelsea postcode.
Answers
Extensions in Kensington and Chelsea — common questions
Do I need planning permission for extensions in Kensington and Chelsea?
It depends on the property type and what is proposed. Many single-storey rear extensions and loft conversions fall under permitted development, but those rights do not apply to flats and are restricted in conservation areas or where an Article 4 direction applies. We check the planning position for your specific address before quoting, and tell you in writing which route applies.
How do you price the work?
From a site survey, written up as a fixed and itemised scope before any deposit is discussed. If something genuinely unforeseen appears once work is opened up, it is priced and agreed in writing before we continue — never added to the final invoice after the fact.
When do I pay?
In arrears of work completed. You pay for work that has been done and inspected, not for work that has been promised. This has been how the company operates since 2008.
Which postcodes in Kensington and Chelsea do you cover?
We work across the whole borough, including SW3, SW5, SW7, SW10, W8, W10 and the surrounding districts.
Who is the planning authority for Kensington and Chelsea?
Royal Borough of Kensington and Chelsea is the local planning authority and also runs building control for the borough. Planning applications, prior approval submissions and building control applications for your property all go to them, and we handle those submissions as part of the contract.
Do you handle Party Wall notices?
Yes, where the work requires them. Under the Party Wall etc. Act 1996, notifiable work on a shared wall needs 2 months written notice to the adjoining owner, while excavation near a neighbouring structure and building at the line of junction need 1 month. We serve the notices and manage the award process as part of the job.
Will I get certificates at the end?
Yes. Electrical work is tested and certificated under Part P, and building control issues a completion certificate where an application was required. You receive the handover pack — it is what a buyer's solicitor will ask for when you eventually sell.
How long will it take?
It depends entirely on scope, and we give a programme with the written quote rather than a guess on the phone. What we will not do is start a job we cannot resource, which is the usual reason a build stalls halfway through.
Also in Kensington and Chelsea
Our other services in Kensington and Chelsea
Nearby
Extensions in nearby areas
More on extensions across London, or see everything we do in Kensington and Chelsea.
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Get a price for extensions in Kensington and Chelsea
A picture and a postcode tells us more than any enquiry form. You will get a straight answer about cost and whether it needs planning permission.