Single Storey Extension Design Services

Ground Floor Space, Done Right. Sussex & Surrey.

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Why Sussex Homeowners Trust ArchEvolve With Single Storey Extensions

A single storey extension is often the most straightforward route to permitted development, but only when the design is prepared correctly from the start. ArchEvolve is MCIAT-chartered with 15 years of regional experience.

      
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   Jonathan Gilbert 
 
 
 
 Trustindex verifies that the original source of the review is Google. I would highly recommend Alex and his company. He has amazing suggestions as well as taking into account our preferences and ideas too. He is easily accessible and has been so helpful in answering all our many questions! Looking forward to seeing our vision come to life!
  
 
      Posted on Google  
   
   James Riley 
 
 
 
 Trustindex verifies that the original source of the review is Google. Alex was really helpful throughout the whole process. This was our first ever project like this and he was on hand to answer MANY questions!
  
 
      Posted on Google  
   
   Nick Rutter 
 
 
 
 Trustindex verifies that the original source of the review is Google. Alex was so helpful from start to finish, great communication throughout. Would strongly recommend and will definitely use their services again in the future!
  
 
      Posted on Google  
   
   arron tully 
 
 
 
 Trustindex verifies that the original source of the review is Google. Alex at Arch Evolve assisted with obtaining planning permission for a couple of extensions that we were intending on doing. Very professional and offered allot of very helpful advice. Very Happy Thank you.
  
 
      Posted on Google  
   
   Marcus Eaton 
 
 
 
 Trustindex verifies that the original source of the review is Google. I have worked with Alex on many projects over the years and he has always been brilliant! Looking forward to working together again soon. Very professional and smooth process throughout the whole process.
  
 
      Posted on Google  
   
   Charlotte Morley 
 
 
 
 Trustindex verifies that the original source of the review is Google. Archevolve has completed a number of plans for us due to changing my mind regularly. They have been consistently patient & listened to my requirements at all time. Alex has then been on hand for our builders if required. Fantastic company & highly recommended
  
 
      Posted on Google  
   
   Peter Proto 
 
 
 
 Trustindex verifies that the original source of the review is Google. Used Alex for our large project, loft conversion, side garage and rear extension. Unbelievable service from start to finish. We are over the moon with the finish. Thank you so much!!
  
 
      Posted on Google  
   
   Tony Maio 
 
 
 
 Trustindex verifies that the original source of the review is Google. Great service, they had an excellent understanding of my requirements. They applied great attention to detail, with a  fast and very efficient service together very reasonable costs. I highly recommend this firm.

Our services

Single Storey Extensions Alongside Related Services

A single storey extension is frequently combined with other work. If you are also extending to the side, see our side return extension page, or compare against a double storey extension if you need more overall floor area. Many clients pair a single storey rear extension with a new kitchen extension layout. For the full range, visit our house extension design services hub.

Completed rear extension at Oldfield Crescent

17 services · Sussex & Surrey

Residential

Extensions, conversions and whole-home projects for homeowners, with site visits across West Sussex, East Sussex and Surrey.

Extensions

House extensions Single storey extensions Double storey extensions Rear extensions Side return extensions Wrap around extensions Kitchen extensions Glass extensions

Conversions

Loft conversions Garage conversions Basement conversions Barn conversions

Whole home

House refurbishment Interior design Listed building design Self-build design Sustainable design

20 services · Nationwide

Developers & Commercial

Planning and technical design for developers and commercial clients across England.

Developer services

Design for developers Planning for developers Technical design for housing

Site & feasibility

Housing development feasibility Development site appraisals Residential masterplanning

Conversions

Commercial conversions Office to residential Flat conversions

Development types

New build schemes Residential developments Blocks of flats Infill housing Brownfield sites Affordable housing Mixed-use developments Care homes Student accommodation HMOs Rooftop developments

3D visualisation of a rear extension design

15 services · Homeowners and developers

Planning & Drawings

From the first feasibility check to construction drawings, in the order a project needs them.

01Feasibility & survey

Feasibility studies Measured building surveys Pre-application advice 3D visualisations

02Planning

Planning applications Planning drawings Permitted development Design and access statements Outline planning Reserved matters Discharge of conditions

03Technical & construction

Building regulations drawings Construction drawings Technical design for housing Contract administration

Single Storey Extensions: Getting Permitted Development Right

Single storey extensions are the most common project type ArchEvolve designs, and the one where permitted development rules are most frequently misunderstood. Small mistakes at the design stage can push a straightforward project into a full planning application.

Common challenges

Confusion over permitted development size limits
Designs that create a dark, boxed-in kitchen or living space
Roof and drainage details missed until construction
Neighbour consultation scheme requirements overlooked
Poor integration between old and new roof lines
Quotes that do not include Building Regulations

How ArchEvolve solves them

Permitted development assessed accurately before design starts
Rooflights and glazing positioned for maximum natural light
Roof and drainage detailing resolved at concept stage
Neighbour consultation handled as part of the planning process
Fixed-scope fees covering design through to Building Regulations
Fixed-scope fees covering design through to Building Regulations

How an ArchEvolve Project Works

Every project follows a clear, stage-by-stage process aligned with the RIBA Plan of Work framework.

Initial Consultation

We discuss your brief, site and budget for your single storey extension project, along with any planning constraints specific to your council. Free, no obligation.

Feasibility Assessment

We assess planning viability and site constraints before any design fees are committed. This includes confirming whether the extension qualifies as permitted development or needs a full application.

Concept Design

We develop the single storey extension design in 3D and produce Enscape renders for your review before planning is prepared.

Planning Application

We prepare and submit the full application to your local planning authority and manage it through to decision.

Building Regulations

We produce the full Building Regulations package covering structure, thermal performance, drainage and fire safety. Single storey roof structures and drainage connections are checked in detail at this stage.

Construction Drawings

We deliver the complete technical drawing set your contractor needs to build your single storey extension accurately on site.

Construction Support

We remain available during the build to respond to queries and issue drawing updates where required.

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Areas we cover

Proudly Serving Homeowners Across Sussex and Surrey

Residential projects across West Sussex, East Sussex and Surrey, with site visits and local planning knowledge. Developer and commercial projects are delivered across England.

3Counties

14Towns

UKDevelopers

Town not listed? Ask us

West Sussex11 towns

Storrington Worthing Horsham Chichester Crawley Littlehampton Bognor Regis Burgess Hill Steyning Findon Hassocks

East Sussex2 towns

Brighton Eastbourne

Surrey1 town

Guildford

Developer or commercial project outside Sussex?

We work across England →

A Different Standard of Design for Single Storey Extensions in Sussex and Surrey

Most practices in the region still work in 2D CAD. ArchEvolve designs single storey extension projects in Revit and renders in Enscape, so you see the finished space before planning is submitted.

3D Visualisations Included

Every single storey extension project is modelled in Revit and rendered in Enscape. You see accurate light, materials and spatial quality before a planning application goes in.

Faster Planning Submissions

Drawings produced in a coordinated 3D environment are more complete and less prone to officer queries, which keeps your single storey extension timeline on track.

Local Planning Knowledge

ArchEvolve has submitted single storey extension applications across West Sussex, East Sussex and Surrey planning authorities. Your submission is prepared for the specific council from day one.

End-to-End Service

From feasibility through to construction drawings, Alex Page manages every stage of your single storey extension project personally. No handoffs, no junior staff taking over mid-project.

Single Storey Extension Design Across Sussex and Surrey

From Worthing bungalows to Guildford family homes, ArchEvolve designs single storey extensions suited to the property type and council.

Many single storey rear extensions fall under permitted development rights, subject to size limits that vary for detached, semi-detached and terraced properties. Side extensions and extensions on designated land, such as conservation areas, usually need full planning permission. ArchEvolve confirms your specific position at the free initial consultation.

Limits depend on your property type and whether a neighbour consultation scheme applies for larger single storey rear extensions. Our guide to how far you can extend without planning permission sets out the current thresholds in detail.

Costs depend on floor area, specification and groundworks. See our house extension cost guide for typical ranges, or get in touch for a fixed-scope design fee quote.

If the extension meets permitted development criteria, a full planning application is not required, although a Lawful Development Certificate is recommended to confirm this in writing. ArchEvolve prepares this alongside the design where appropriate.

The service covers feasibility and permitted development assessment, 3D concept design, planning or Lawful Development Certificate application, full Building Regulations drawings, and construction drawings for your builder.

This is one of the most common reasons for objections and refusals. ArchEvolve designs single storey extensions with roof pitch, window placement and boundary distances considered from the outset to minimise the risk of neighbour objections affecting your timeline.

ArchEvolve covers West Sussex, East Sussex and Surrey, including Worthing, Horsham, Chichester, Crawley, Guildford and Brighton, with a free initial consultation offered to all homeowners in the region.

Frequently Asked Questions

Start Your Single Storey Extension Design Today

Free initial consultation for homeowners across Sussex and Surrey. Get in touch to discuss your ground floor extension.