CITB logo Trust Mark logo EBC logo FMB logo

Mon - Sat 8.00 - 18.00

0203 515 0074

Contact us
Kitchen Extension Gospel Oak NW5
Kitchen Extension Gospel Oak NW5

Located within the Gospel Oak, NW5 area, the project required us to concentrate on the development of a 4 bedroom semi-detached house that had very outdated interiors, cramped and contrived layout and a poorly built and uninsulated single storey extension in the garden. The client desired a full house renovation and a new kitchen extension that is better linked with the existing interiors of the house. more info >

What Our Clients Say
What Our Clients Say

Find out what they had to say about our refurbishment and construction services. more info >

Side Return Kitchen Extension Chiswick W4
Side Return Kitchen Extension Chiswick W4

Sigma Construction UK was appointed by a private client to renovate their west London terrace home. To provide greater kitchen/living space with the increased quality of light and connectivity with the garden. The architects proposed a new side return kitchen extension. more info >

House Extension Kilburn NW6
House Extension Kilburn NW6

Sigma Construction has recently completed a House Extension in West Hampstead, London NW6, creating a beautiful and spacious open-plan kitchen for our client. more info >

Kitchen Extension Cost
Kitchen Extension Cost

Our Design and Build service provides a full ‘turn-key’ solution that ensures the continuation of quality and service to our clients. more info >

Sigma Construction UK

Sigma Construction UK Sigma Construction UK
9.3 out of 10 based on 12 user ratings by .

Kitchen Extensions  

Kitchen extensions at a good price in London

Many terraced houses have a side space at the back that's usually used for garden storage, but which could be used to widen what is often a long, narrow kitchen. The biggest benefit of a side extension is the additional width gained for the kitchen. 


We have many years’ experience in building side return kitchen extensions. Together with our architects and structural engineers we work to create the perfect extension, constructed to your specifications, and designed to fit in with the style of your property.


          We design and build:  

·         single storey house extension

·         double storey house extension

·         kitchen extensions

·         bedroom extension

·         conversion houses to flats     


This video demonstrates process of building side return kitchen extension



How we will assist you 

We will provide you with a team of qualifying tradesmen. A kitchen extensions involve every type of skill, from preparing architectural drawings, obtaining planning permission and dealing with building control, managing construction through to the final decorating touches. We offer you full range of services under one roof to ensure your building project run smoothly, on time and within you budget.



Kitchen Extension FAQ


1. I want to build a kitchen extension; Do I need an architect?  

Whilst it is not essential to employ an architect to design your project it is wise to listen to the advice of professionals who have carried out similar works. Architects have invaluable experience from past projects that relate not only to the build but also planning regulations and building restrictions in your area. 

The primary reason to consult an architect is most certainly to employ their design skills. Ultimately, their understanding of spatial design and specification of appropriate materials is worth its weight in gold. A clever use of material, light and layout can transform a space and give an end result that would otherwise not have been possible.


2. Do you carry out the complete project?  

The Sigma Construction UK ‘Turnkey’ solution is a proven alternative to a traditional form of contract and permits the client one point of contact, one seamlessly integrated team and one price.

Our design and build process divides each project into clear stages; Briefing, Concept Design, Detailed Design, Planning & Statutory Applications and Construction.

Integrated interior design, architectural and structural teams work alongside a skilled team of builders and tradesmen, all closely managed by our Project Management team to ensure the streamlined progression through to completion. Sigma Construction UK provide a single point of responsibility.


3. Can you arrange for Planning Permission and Building Approval?

Sigma Construction UK offers a complete ‘turnkey’ solution to your project needs.

We can take care of every aspect of the design and build process and ensure all statutory permissions are applied for.


4. What is permitted development?  

You can make certain types of minor changes to your house without needing to apply for planning permission. These are called "permitted development rights" and are specific to each borough council. They derive from a general planning permission granted on a national scale by Parliament.

They are generally outlined on your council website but in brief, can be read here:


5.  What is a Party Wall Agreement? Do I need to ask my formal agreement with my neighbour?   

A Party Wall Agreement or ‘Award’ is required when carrying out works to an adjoining wall or boundary between properties. Whilst it is often times polite to raise any building project with your neighbour, warning them of noise or future disruption, it is essential to sign a Party Wall Agreement.

In short the Award, written up by a Chartered Surveyor, will outline the restrictions imposed by either party, on working hours, access, time limit to complete work and Assurances and Indemnities for the responsible parties. A Schedule of Conditions will be written up with supporting photographic evidence showing the status of the built fabric prior to commencement of Works. If any cracks or damage is caused during or immediately following the completion of Works both parties will have a record against which costs of repair work can be agreed. We often advise our clients to approach neighbours with a nice bottle of wine at this early stage in the project as it helps to set good foundations on which to build!


6. How much will it cost? 

As a baseline estimate a typical 25sqm side return extension would cost in the region of £40,000 to £65,000 plus VAT. This is based on our experience and is intended as guidance only. A breakdown of associated costs is listed under our Side Return Extension Costs and will be subject to change depending on the particulars of each project, selected materials, kitchen appliances and cabinets. It is certainly wise to allow a further 10% contingency sum for those unforeseen eventualities that may crop up. For an accurate quotation please arrange a consultation with a member of our team.


7.  How long will the project take? 

This depends on the particulars of each side return extension project. Factors such as size, location, weather and complexity of design can all have an influence on project length. As guidance, a typical side return kitchen extension project will generally take 8-10 weeks for construction. It is advisable to work through your design thoroughly before starting works as changes later down the line may be costly. Please note that you will be required to wait a statutory 8 weeks to receive notice on any submitted Planning Applications.


8.  Is your work guaranteed?  

We are Members of the Federation of Master Builders and part of the Government TrustMark Scheme and abide by all their rules and practices.

We provide cover on all our work with a 2-year guarantee following project completion



0203 515 0074 


All rights reserved. Copyright © 2005 - 2021 Builders construction companies in London UK - building renovation





N1,  N2,  N3,  N4,  N5,  N6,  N7,  N8,  N9,  N10,  N11,  N12,  N13,  N14,  N15,  N16,  N17, N18, N19 , N20, N21 , N22 , NW1 , NW2,  NW3 , NW4,  NW5 , NW6 W8, NW9, NW10, NW11, NW12, NW13, NW14, NW15

Islington, Barnsbury, Canonbury, East Finchley, Finchley Central, Finsbury Park, Manor House, Highbury, Highgate, Holloway, Hornsey, Crouch End, Lower Edmonton, Muswell Hill, Friern Barnet, New Southgate, North Finchley, Woodside Park, Palmers Green, Southgate, Seven Sisters, Stoke Newington, Stamford Hill, Tottenham,Upper Edmonton, Archway, Tufnell Park,Whetstone, Totteridge,  Winchmore Hill, Wood Green, Alexandra Palace, Regent’s Park, Camden Town, Cricklewood, Neasden, Hampstead, Swiss Cottage, Hendon, Brent Cross, Kentish Town, West Hampstead, Kilburn, Queens Park, Mill Hill, St John’s Wood, Kinsbury, Colindale, Willesden, Harlesden, Kensal Green, Golders Green, Hampstead,  Garden Suburb, Edgware, Harrow On The Hill


W1, W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W12, W13, W14
Isleworth, Acton, Eastcote, Bayswater, Charlton, Brook Green, Chiswick, Ealing, Uxbridge, Greenford, Hanger Lane, Hanwell, Hammersmith, Holland Park, Westminster, Kensington, Elsham, Notting Hill, East Molesley, Ladbroke Grove, Marylebone, Mayfair, North Kensington, Warwick Avenue, Osterley, Paddington, Perivale, Shepherd’s Bush, Strand, Addlestone, West Brompton, Kensal Green, Queens Park, West Ealing, North Kensington, Queens Park, Kensington and Chelsea Notting Hill, Holland Park, Maida Hill, Maida Vale, Little Venice, West Ealing, Northfields Ealing, West Kensington, Kensington Olympia Fitzrovia, Tottenham Court Road, Camden, Chiswick, Gunnersbury, Turnham Green, Bedford Park,
Paddington, Bayswater, Hyde Park


W1 , WC1. WC2,  EC1,  EC2, EC3, EC4 , E8    

Baker Street, Bloomsbury, Holborn, Kings Cross, Gray's Inn, New Oxford Street Covent Garden, The Strand, Leicester Square, Charing Cross, Aldwych, Barbican, Belgravia, Soho, ,Clarkenwell , Hackney


SW1, SW2, SW3, SW4, SW9, SW5, SW6, SW10, SW12, SW13, SW14, SW15,  SW16,  SW17, SW18,  SW19

Earls Court, Pimlico, Brixton,  Streatham Hill, Tulse Hill, Clapham Park, Chelsea  Brompton,  Knightsbridge, Clapham, Stockwell, Fulham, West Brompton, Chelsea, Balham, Clapham South Barnes Mortlake, East Sheen Putney Roehampton Kingston Vale,  Streatham Norbury Thornton Heath Streatham Park  Furzedown Vale, Wandsworth,  Merton, Wandsworth, Southfields, Earlsfield Wandsworth, Wimbledon, Colliers Wood, Merton Park, Southfields, North Morden Merton,