Extensions & Alterations
More space, more light and more value — without the cost and upheaval of moving.
Create More Space Without Moving
Whether your family is growing, your home needs a better layout or you simply want to make better use of the space you already have, an extension or alteration can transform the way you live.
Astonmart World provides professionally managed extension and alteration services across South East London, North Kent and Northamptonshire. From smaller structural changes to substantial single- and double-storey extensions, we manage the building work with clear pricing, organised scheduling and regular communication.
Extension Services
Single & Double-Storey Extensions
Create additional living, dining, bedroom or family space with an extension designed around your existing property.
Rear & Side-Return Extensions
Make better use of unused rear or side space, particularly on period and family properties.
Wrap-Around Extensions
Combine rear and side extensions to create a larger, more open and practical living area.
Kitchen Extensions
Create larger, brighter kitchens and connected dining and living spaces designed around how you use your home.
Garden Rooms & Outbuildings
Add useful space for a home office, studio, workshop, hobbies, storage or other purposes.
Alterations & Structural Work
We also undertake internal alterations and structural changes, including open-plan layouts, knock-throughs, load-bearing wall removal and associated structural works. Where specialist structural design or calculations are required, these can be incorporated into the project before work begins.
A Clear Process From Start to Finish
Every project begins with a free site visit. We assess the property, discuss your requirements and establish the scope of work. You then receive a written quotation setting out the agreed works, exclusions, programme and payment stages. Where applicable, we coordinate building control requirements and inspections throughout the project. Any changes to the agreed work are discussed and confirmed in writing before additional work proceeds.
Ready to Create More Space?
Tell us what you have in mind and arrange your free site visit.
Free, no-obligation site visit
Fixed written quotations
Clear payment stages
Building regulations managed
One named point of contact
Professionally supervised work
Written workmanship guarantee
Areas We Cover
South East London and North Kent — Bromley, Orpington, Bexleyheath, Sidcup, Eltham, Lewisham, Greenwich, Croydon, Dartford, Sevenoaks, Beckenham, Petts Wood, West Wickham — and Northamptonshire and the East Midlands, including Northampton, Rushden, Wellingborough, Kettering, Towcester, Daventry, Blisworth and the Milton Keynes borders.
Planning a Project? Let's Talk It Through.
Whether you are considering an extension, refurbishment, conversion, groundwork project or property improvement, we would be happy to discuss your plans.
Tell us what you have in mind and arrange a free site visit. We aim to respond to enquiries within the same working day.