All you need to know about House Extensions in London… in a nutshell!

London has seen a surge in house extensions, basement conversions and loft conversions in the last five years. With soaring stamp duty costs and the high overall cost of moving, homeowners with growing families who need the extra space are increasingly choosing to increase the area in their existing properties rather than up sticks and move home.

Setting out on a house extension project requires, amongst other things a healthy amount of patience [Symbol]. There are several details to consider and decisions to make.

We suggest that you begin by creating a project management spreadsheet (we’ve created one for you) even if you have a dedicated project manager so that you are both on the same page with regards to costs, timelines, delivery schedules and communication with various suppliers.

The first step is to appoint an architect. Your architect is probably the most important person in your project. Make sure you appoint an architect that understands your needs and your vision and is able to marry the two with a plan and solution that your local council will approve.


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Arhictects 2019

The SDA Build team have meticulously curated a list of talented architects serving the London and Greater London areas. All the architects on our list are RIBA certified and have vetted by Houzz.

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Whether or not you need planning permission will depend on the scope of your plans. Do you want a single storey extension or a double storey extension? How far do you intend going out? What are the current rules with regards to planning in your local council? All these will determine whether you need to apply for planning permission or whether your works fall under permitted development guidelines. Your architect should know this.

This process usually takes about 8 weeks. You can either sit back and relax or start researching on the various other decisions you will have to make such as:

  • Rental property if you are moving out
  • Flooring and carpets
  • Heating
  • Windows
  • Internal Doors and door fittings
  • External Doors
  • Electrics and lighting
  • Tiles
  • Bathroom furniture and sanitaryware
  • Kitchen furniture and appliances
  • Blinds
  • Fitted furniture in bedrooms
  • Patio or decking
  • Paint colours
  • Home alarm & entertainment system

The list can go on depending on your house extension project, whether it’s a kitchen extension, a bedroom with an en-suite, a guest room, a playroom or games room, a home office or even a gym.


Types of extensions

Single Storey rear extension

If you have a good-sized garden at the back of the house, you could extend the back of the house out (subject to planning rules) and create a more intimate experience with your garden. Large sliding or bifold doors along with an open plan space, can give you an added sense of light and air and almost brings the outdoor, indoors.

Double Storey rear extension

If you feel you need more living space upstairs, perhaps larger bedrooms or an en-suite bathroom or a home office, you could build additional space on top of your single storey extension. In some of the properties we have worked on, we have created luxurious bedrooms with walk-in closets, fitted wardrobes, children’s studies and guest rooms… the possibilities are limitless.

Side extension

Several homes have space between the side of their homes and the fence. Why not think about extending the house into this space? For many home owners this is the perfect opportunity to open up the kitchen, create a home gym a guest room or a room for ageing parents or even a home office with perhaps a separate entrance.

Wrap around extension

As the name suggests, a wrap-around extension is a side and back extension around the existing home. You are effectively changing the layout of the house in totality, allowing you to re configure and re plan how you use the area. You could open up the downstairs completely (this is currently what’s on trend in London.), to give yourself an open plan kitchen-living space or create a games room or even a state of the art cinema room.

As a company that provides a complete design and build service, we have worked with a number of clients in the South East of the country to help them through the entire process of building their house extension, right from the start with architectural design and planning permission, through to the finished product.

If you are planning a house extension and need some guidance on how to go about it, give us a call on 0208 191 7595 or email us at to discuss your project.

To have a look at the kind of work we have done, why not download our free brochure? And if you need any help with managing your building project, our free project management checklist has been hugely popular.