Are you feeling cramped in your current space? Imagine having the room to cook, dine, work, or relax without limitations, all within the home you love. At SM London Construction, we specialise in bespoke single-storey extensions.
Our creations not only increase your living space but also enrich your home’s design and functionality.
If you want to expand your kitchen, create an open-plan living area, or add a workspace, our bespoke single storey extensions are the ideal choice. We blend luxury design with high-quality craftsmanship. This ensures that your new space seamlessly integrates with your existing home, tailored to fit your unique needs. With our team by your side, your dream home transformation is within reach.
Book your consultation online or call us on 07961 817 505 or 0208 226 5511, and let’s start designing the perfect extension for your home.



If you want a roomy kitchen, a big living area, or a home office, a bespoke single-storey extension can make it happen. Our team specialises in building extensions that blend perfectly with your home, so you get the extra space you need.
We offer designs that enhance your home’s appearance and functionality. You can expand sideways with a side return extension or open up to the garden with a rear extension. For the best space, a wrap-around extension adds side and rear areas. This creates a spacious living area, ideal for family gatherings or a variety of versatile uses.
Not sure which design suits you? Our complimentary consultation allows us to assess your property, learn your needs, and explore the best options. With our bespoke approach, we’ll transform your home into the space you’ve always dreamed of. Browse our gallery to see our stunning work.
We ensure that your extension project proceeds smoothly from start to finish. This way, there’s minimal disruption. Our dedicated team collaborates with you throughout every stage of the process. We ensure clear communication and keep everything on track.
First, we learn about your goals. Then, we assess your property. This helps us create a solution that perfectly fits your needs. Once we understand your vision, our architects will create custom designs for your home. They will provide detailed 3D visuals, allowing you to see your ideas before construction begins. We take care of securing planning permission and ensure your extension meets all the building regulations. We handle all the paperwork on your behalf.
During the construction phase, we use the finest materials and expert craftsmanship to bring your vision to life. Throughout the project, we maintain regular updates, keeping you informed and confident in the progress. Once the work is done, we will have a final walkthrough. This allows us to confirm that everything meets your expectations. If needed, we’ll make final adjustments to ensure you’re delighted with your new space.
To learn more about how we work and the process you can expect when partnering with us, click below.
The average full home renovation in the UK costs between £45,000 and £76,500, while larger projects, such as a single storey extension in London, can range from £75,000 to over £150,000.
Needless to say, the cost depends on the size, build complexity, and what is already in place on the site.
A clear budget starts with understanding the main cost drivers:
For typical layouts and scope examples, visit our recent Projects page.
Yes, building regulations approval applies to all single storey extensions, even when planning permission is not required. Compliance focuses on safety, performance, and long-term durability, including:
We manage building control coordination as part of our end-to-end service. You can learn more about this by visiting SM London Construction’sOur Process guide.
Permitted development rules often allow rear extensions up to 3 metres, or up to 6 metres with prior approval, depending on the property type. Height limits and proximity to boundaries also apply. These rules vary by location. Confirming eligibility before design work avoids delays. Our team supports this as part of our structured build process.
In most London areas, £20,000 is unlikely to cover a complete extension once essential works are included. £30,000 can be possible for a very small, simple build, but it is still a tight budget.
These are the costs people often miss:
If you want a realistic scope based on your property, get in touch and review how we run projects on Our Process page.
The most cost-effective option is usually a simple rear extension with a straightforward footprint and standard materials. Avoiding complex steelwork, bespoke glazing, or major drainage changes can reduce costs. Clear planning and professional management also prevent expensive mistakes. Viewing a completed single storey extension can helps set expectations, and you can see examples of this on our Gallery page.
An architect is not legally required, but professional drawings are strongly recommended. Accurate plans support planning approval, building control sign off, and reliable pricing. Good design also ensures the extension integrates properly with the existing home. Many homeowners choose a design and build approach. Learn more about design support via our Architectural Services.
Most single storey extensions require a structural engineer, especially where load-bearing walls are removed or steel beams are installed. Structural calculations ensure safety and compliance with building regulations. This protects both the property and occupants long-term. Structural input is coordinated alongside design through our Architectural Services.
Groundworks and structural elements are often the largest cost drivers. Foundations, drainage alterations, and steel supports can significantly affect budgets, particularly on restricted London sites. High specification glazing and bespoke finishes also increase costs. Understanding these factors early allows smarter design decisions. You can see how these elements come together in real builds on our Projects page.
Yes, all single storey extensions must meet building regulations, regardless of planning status. This covers structure, insulation, drainage, fire safety, and energy efficiency. Approval ensures the extension is safe and compliant. Managing this correctly avoids issues during resale or refinancing. We handle compliance as part of our end-to-end service, as explained in Our Process page.
Foundation depth depends on soil type, nearby trees, drainage, and existing structures. In London, foundations are often around one metre deep, but clay soils can require deeper footings. Building control inspections confirm the correct depth on site, and this is managed as part of our compliant construction process.
Build times vary depending on size, complexity, and site conditions. Many single storey extensions take between 10 and 16 weeks once construction begins. Weather, access, and structural work can affect timelines. Clear scheduling and communication help keep projects on track. Our build stages are explained in Our Process guide.
A properly built single storey extension should last as long as the original property, often 60 years or more. Longevity depends on materials, foundations, workmanship, and ongoing maintenance. Building to current regulations is essential, and choosing an experienced contractor like SM London Construction will reduce long-term risk. Our commitment to quality is supported by structured Aftercare services.
In many cases, a well-designed single storey extension adds value by increasing usable space and improving layout. Kitchens and open-plan living areas are particularly attractive to buyers. Value uplift depends on build quality, location, and design integration. Viewing completed work can help assess outcomes, and you can explore examples on our Gallery page.
Extending is often more cost-effective than moving in London once stamp duty, legal fees, and relocation costs are considered. A single storey extension allows you to gain space without leaving your area. Yet the right choice depends on budget and planning constraints and reviewing our completed projects can help inform decisions.
Most extension problems come from poor preparation or unclear project control, rather than the idea itself. The most common issues we see are:
Client feedback on how SM London Construction manage projects is available on our Reviews page, and you can see completed results on our Projects page.