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Single-Storey Extensions in Surrey & Elmbridge

  • 30 years experience
  • 10-year structural guarantee
  • Fixed fee quotation
  • 5% Scheduling discount
  • 500+ Successful projects

Add practical ground-floor space with a well-planned single-storey extension designed around light, flow, comfort and everyday family living.

Single-Storey Extensions in Surrey & Elmbridge by HWP Design and Build

Single-storey extension builders for Surrey family homes

A single-storey extension is one of the most flexible ways to improve a home. It can create a larger kitchen, open-plan dining space, garden room, utility area, home office or more practical family living space without adding another floor.

HWP Design & Build delivers single-storey extensions across Elmbridge, East Molesey, Esher, Thames Ditton, Surbiton, Kingston and nearby Surrey towns. We coordinate the design, planning route, structure, drainage, roof design, glazing, insulation, Building Regulations and finish specification.

Whether you are considering a modest rear extension, a side return or a larger kitchen extension, we help you choose a route that suits the property, garden, budget and long-term use of the new space.

Clear scope, fixed-price clarity and local accountability

HWP Design & Build is the trading name of SMA Design & Build Ltd. We combine over 30 years of hands-on industry experience with practical design thinking, insured delivery, tidy site management, quality finishing and aftercare support.

Learn more about our process, accreditations, insurance and guarantees, aftercare and customer reviews.

Single-storey extension build progress in a Surrey home
Single-storey extension completed with high-quality finishes

Single-Storey Extensions in Surrey & Elmbridge:

HWP Design & Build provides single-storey extension design and construction across Surrey, Elmbridge and nearby South West London. We assess garden depth, boundaries, foundations, drainage, structural openings, roof form, glazing, planning, Building Regulations, access and finish specification before preparing a fixed-price quotation.

Is your home suitable for a single-storey extension?

Most successful single-storey extensions start with a feasibility review. We assess how the extension will connect with the existing home, whether the garden can support the footprint and which roof, glazing and structural options are realistic.

  • Garden depth, boundary position and neighbouring windows.
  • Existing kitchen, dining and living room layout.
  • Foundations, ground conditions, drainage and service routes.
  • Structural openings, steelwork and temporary works.
  • Flat roof, pitched roof, roof lantern or rooflight options.
  • Planning, permitted development, party wall and Building Regulations considerations.

What type of single-storey extension is right for your home?

Single-storey extensions can solve different layout problems. The best option depends on your plot, budget, garden, planning position and how you want to use the space.

Option Best suited to Typical benefit
Rear single-storey extension Homes with enough garden depth behind the existing house. Creates a larger kitchen, dining or family living space.
Side single-storey extension Homes with underused side space or side access. Adds width and can improve circulation, storage and layout.
Kitchen extension Families wanting a better everyday cooking, dining and entertaining space. Creates the practical heart of the home.
Single-storey extension with lantern Homes where the middle of the plan needs more light. Improves daylight and makes the new area feel more generous.
Single-storey extension with refurbishment Homes where the existing ground floor also needs reworking. Creates a more joined-up layout rather than a bolt-on room.

Planning permission, permitted development and local design context

Many single-storey extensions can fall under permitted development where limits and conditions are met, but this is not guaranteed. Depth, height, boundary distance, materials, previous extensions, conservation context and local restrictions all need to be checked before relying on permitted development.

We can review whether your project is likely to need planning permission, whether a lawful development certificate is sensible, and how the design should respond to local expectations in Elmbridge, Surrey and nearby South West London.

  • Permitted development checks for size, height, depth, boundary position and materials.
  • Householder planning applications where the proposal exceeds permitted development limits.
  • Conservation area, neighbour, daylight, overlooking and street-scene sensitivity reviews.
  • Coordination between drawings, structural information, specification and build scope.

Building Regulations, structure and technical coordination

Extensions that create habitable space normally need Building Regulations approval. This protects the safety, comfort and long-term value of the finished work, especially where foundations, structure, drainage, insulation, ventilation, glazing, electrics, heating and fire safety are involved.

  • Foundations, ground conditions, drainage and structural stability.
  • Steelwork, load transfer, temporary works and roof structure.
  • Thermal insulation, airtightness, ventilation and condensation control.
  • Heating, plumbing, electrics, lighting and service alterations.
  • Fire safety, glazing safety, smoke detection and escape considerations.
  • Inspection coordination and completion documentation for future sale or refinancing.

We coordinate Building Regulations support so the finished extension is properly designed, checked and signed off.

Party wall, neighbours, drainage and access

Many house extensions around Surrey and South West London involve shared boundaries, neighbouring foundations, drainage routes, tight access and disruption to family life. These practical issues should be reviewed before work starts.

  • Party wall matters: notices may be required for work on or near shared boundaries or excavation close to neighbouring structures.
  • Drainage: manholes, soil pipes, rainwater routes and new kitchen or utility layouts can influence the build route.
  • Access: tighter plots can affect deliveries, waste removal, scaffolding, temporary works and site protection.
  • Neighbour impact: daylight, overlooking, noise and disruption should be considered early.

Where required, we can support the project with party wall advice, build sequencing and clear communication around the practical impact of the works.

How much does a single-storey extension cost in Surrey?

Single-storey extension cost depends on footprint, foundations, drainage, structural openings, roof design, glazing, kitchen or bathroom specification, heating, electrics, finishes and how much internal reconfiguration is required. We avoid misleading headline prices because each property, scope and specification is different.

Once we understand the property and project brief, we prepare a clearer quotation based on real site conditions, drawings, specification, approvals and finish expectations.

Cost factor Why it affects the quotation
Extension size and footprint A larger footprint increases structure, foundations, roofing, glazing, labour and finishes.
Foundations and ground conditions Soil, trees, drainage and existing structures can affect engineering and build complexity.
Roof type and glazing Flat roofs, pitched roofs, roof lanterns and rooflights all change cost and performance.
Structural openings Large openings between the old and new areas require steelwork and careful sequencing.
Kitchens and utilities Cabinetry, appliances, plumbing, drainage and electrics often drive a large part of the budget.
Finish specification Flooring, joinery, lighting, heating, decoration and exterior materials affect the final price.

For broader budget planning, read our Surrey house extension cost guide or our Elmbridge house extension costs, planning and timeline guide.

Our single-storey extension process

We use a clear process so design, approvals, pricing and construction remain joined up from the start.

1. Survey and feasibility

We review the existing home, access, boundaries, drainage, structure, planning constraints and how the new space should function.

2. Design and approvals

We coordinate design development, structural input, planning where required and Building Regulations information.

3. Fixed-price quotation

We price from a defined scope and specification so you understand what is included before the build starts.

4. Managed build and handover

We manage the work, coordinate inspections, complete snagging and provide aftercare support.

What happens after you request a single-storey extension quotation?

We review your enquiry, arrange a suitable time to discuss the property, then assess layout, access, structure, planning route, Building Regulations, likely disruption and the level of finish required before preparing a clear scope.

Start your extension enquiry

Local extension considerations in Elmbridge and Surrey

Extension projects around East Molesey, Esher, Thames Ditton, Kingston, Surbiton, Walton-on-Thames, Weybridge and Cobham often involve established housing stock, neighbouring boundaries, drainage routes, mature trees, conservation sensitivity and restricted access. We review these points early so the design, quotation and programme reflect the real property.

Area Common consideration How we approach it
East Molesey / West Molesey Family homes, rear gardens, shared boundaries and KT8 planning context. Early checks around access, drainage, party wall position, garden connection and buildability.
Hampton Court / Thames Ditton Character homes, river-adjacent settings, conservation sensitivity and proportionate extensions. Designs are tested for scale, materials, roof form, local character and site logistics.
Esher / Claygate Larger family homes, specification-led projects and premium finish expectations. Clear feasibility, design coordination and specification-led pricing before construction.
Kingston / Surbiton Victorian, Edwardian and terrace-style homes with layout and party wall constraints. Practical design around structure, services, neighbours, drainage and sequencing.
Walton-on-Thames / Weybridge / Cobham Detached and semi-detached homes with scope for larger extensions and whole-home upgrades. We coordinate design, specification, structural requirements and build programme as one managed route.

Common single-storey extensions problems we help prevent

The best extension projects are resolved before work starts. We help identify the practical issues that can affect budget, programme, compliance and finish quality.

  • Quotations that exclude drainage, steelwork, glazing, finishes or making good to the existing rooms.
  • Extension depth chosen without considering garden balance, daylight and neighbouring windows.
  • Flat roof, lantern or rooflight details not planned around insulation and ventilation.
  • Large structural openings not coordinated before site work starts.
  • Kitchen, utility, heating and electrical layouts decided too late.
  • Permitted development assumptions made without checking property history or local restrictions.

Why choose HWP Design & Build?

  • Fixed-price clarity: a defined scope and quotation before work begins.
  • One accountable team: design, approvals, construction, finishing and aftercare coordinated through one route.
  • Local experience: house extension support across East Molesey, Elmbridge, Surrey and nearby South West London.
  • Practical design thinking: layout, light, storage, flow, garden connection and daily use considered from the start.
  • Compliance-led delivery: planning, Building Regulations, party wall and inspection requirements reviewed early.
  • Sustainable approach: sensible insulation, ventilation, glazing and material choices to improve comfort and long-term performance.

Single-Storey Extensions in Surrey & Elmbridge across Elmbridge, Surrey and South West London

We are based near the Surrey and London border and regularly support homeowners planning extensions, loft conversions, refurbishments and full home improvements across the local area.

Key locations include East Molesey, West Molesey, Hampton Court, Thames Ditton, Esher, Claygate, Walton-on-Thames, Weybridge, Cobham, Kingston upon Thames, Surbiton, Teddington, Twickenham, Richmond and Wimbledon and nearby South West London.

Single-Storey Extension FAQs for Surrey & Elmbridge Homeowners

Some single-storey extensions can fall under permitted development, but it depends on size, height, depth, boundary position, materials, previous extensions and whether local restrictions apply. We can advise on the safest route.

Rooflights, roof lanterns, glazed doors, internal openings and careful layout planning can all help bring natural light into the new and existing rooms.

Yes. We plan floor levels, thresholds, insulation build-ups and finishes so the transition between the existing home and new extension is as seamless as possible.

Yes, a properly designed extension should be insulated, ventilated and heated to modern standards so it is comfortable year-round.

Yes. We can coordinate survey, design, planning, Building Regulations, structural input, construction, finishing and handover through one managed route.

Often yes, but it depends on access, services, kitchen disruption and structural openings. We plan protection, sequencing and temporary arrangements before work begins.
Rear, side, kitchen and ground-floor extension planning.

Ready to price your single-storey extension?

Whether you are planning a kitchen extension, open-plan living space, garden room or full ground-floor transformation, we can assess your property, explain the best route and provide fixed-price clarity before work begins.

Single-Storey Extensions in Surrey & Elmbridge across East Molesey, Elmbridge, Surrey and nearby South West London.