Our London house extensions team are specialists in constructing all types of extensions, so whether you are considering a single or double storey extension, we can help. An extension can give your property a completely new feel and open up space in your home that you didn’t realise you had. If you and your family are settled in your home but need more space, our experienced team can help you to expand your existing property and avoid the stress of moving. The Market Design and Build can also revamp or upgrade existing extensions to give them a new lease of life.

Our London loft Conversion team can also help anyone who is seeking new space in their home, but haven’t got the external space to extend into. Converting your loft can transform an unused space into an office, playroom or even a new bedroom. Our team of experts truly believe that no job is too large or small, and they will assess your loft space to make a recommendation based on your property.

Our superb 6 Step Process was created a few years ago to help make the building process straightforward and clear for everyone involved. The process gives an individual break down of each stage of the build, allowing you to easily plan and predict what will be happening next. At each step along the way, our project manager will be there to guide you and ensure that the highest quality of work is achieved. 

An initial estimate is totally free of charge.

Within this, we will compile a detailed breakdown of your requirements and then provide an estimate based on the visit/discussion and take you through all the available plans.

A quote can be arranged by contacting us using one of the following methods:

This is an informal discussion of your establishment, followed by arranging a convenient time for a visit in which we will discuss your requirements further.

Upon the agreement of a contract, we aim to start the project within 2 weeks - however most projects can be started within 7 days.

If the project requires ‘planning permission’ then we allow an extra week or two, as it can take up to two weeks for a government reply on whether or not they approve.

Planning permission depends on what work you are intending to carry out. For example, some loft conversions do require such permission and all have to adhere to Building Regulations.

Please see this website for more information:


No matter what size loft you have, we can come to complete an assessment of your property to discuss with you whether a loft conversion is both suitable and cost-effective.

We feel that all lofts can be converted within reason, as the success of any build will depend on what your requirements are for the new space.

Please contact us for an informal discussion about your property.

If you are unsure if an extension would be possible at your property, contact us to arrange a viewing time which is mutually convenient for you and a member of our team. This viewing is totally free and in this period we will offer you advice on extension possibilities as well as measurements & other guidance.

Here at the Market Design & Build, we truly believe no job is too small.

We will happily take on almost any job - our teams thrive on a challenge and take great pride in what they do. We take on a wide range of projects from complicated double storey extensions to simple loft conversions so we are always happy to help.