17 services · Sussex & Surrey
Residential
Extensions, conversions and whole-home projects for homeowners, with site visits across West Sussex, East Sussex and Surrey.
Extensions
Rear Extension Design Services
Reconnecting Your Home With the Garden. Sussex & Surrey.
Why Sussex Homeowners Trust ArchEvolve With Rear Extensions
A rear extension is usually the project that transforms how a family actually uses their home. ArchEvolve is MCIAT-chartered with 350 planning approvals secured across the region.
- 15 years of experience
- 350 planning approvals secured
- 500 projects completed
- Revit 3D modelling as standard
- MCIAT-chartered accreditation
Our services
Rear Extensions Alongside Related Services
Rear extensions are often extended in width with a side return extension, or designed with large glazed openings as a glass extension. Many clients use the new space for a kitchen extension layout. See the full range on our house extension design services hub.
20 services · Nationwide
Developers & Commercial
Planning and technical design for developers and commercial clients across England.
Developer services
Site & feasibility
15 services · Homeowners and developers
Planning & Drawings
From the first feasibility check to construction drawings, in the order a project needs them.
01Feasibility & survey
02Planning
03Technical & construction
Rear Extensions: Where Light and Layout Get Overlooked
A rear extension is frequently reduced to a box on the back of the house, missing the opportunity to genuinely improve how light and space work through the ground floor. The design decisions made at concept stage determine whether the finished room feels generous or cramped.
Common challenges
- Extensions that create a dark middle room between old and new
- Rooflights positioned without proper daylight modelling
- Poor connection between the extension and the existing kitchen or living space
- Boundary and permitted development limits misunderstood
- Drainage and manhole positions ignored until construction
- Designs copied from a template rather than fitted to the plot
How ArchEvolve solves them
- Layouts designed to eliminate dark middle rooms
- Rooflight positions modelled against real daylight and sun path
- Extension and existing space designed as one connected layout
- Permitted development and boundary limits confirmed before design
- Drainage surveyed and resolved at the concept design stage
- Drainage surveyed and resolved at the concept design stage
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 rear 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 checking permitted development limits and boundary distances specific to your garden.
Concept Design
We develop the rear 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. Rear extensions with large glazed openings require additional structural calculations for steel beams, which we coordinate directly with a structural engineer.
Construction Drawings
We deliver the complete technical drawing set your contractor needs to build your rear extension accurately on site.
Construction Support
We remain available during the build to respond to queries and issue drawing updates where required.
0
+
years of experience
0
+
Planning approvals
0
+
projects completed
0
M
largest construction project developed
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
West Sussex11 towns
Developer or commercial project outside Sussex?
We work across England →A Different Standard of Design for Rear Extensions in Sussex and Surrey
Most practices in the region still work in 2D CAD. ArchEvolve designs rear extension projects in Revit and renders in Enscape, so you see the finished space before planning is submitted.
3D Visualisations Included
Every rear 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 rear extension timeline on track.
Local Planning Knowledge
ArchEvolve has submitted rear 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 rear extension project personally. No handoffs, no junior staff taking over mid-project.
Rear Extension Design Across Sussex and Surrey
ArchEvolve designs rear extensions that reconnect homes with their gardens throughout West Sussex, East Sussex and Surrey.
Does a rear extension need planning permission?
Many single storey rear extensions fall under permitted development, subject to depth limits that vary for detached, semi-detached and terraced properties. Our guide to extension limits covers the current thresholds.
How far can I extend the back of my house?
Permitted development depths vary by property type and whether a neighbour consultation scheme is used for larger single storey rear extensions. ArchEvolve confirms your specific limits at the free initial consultation.
How much does a rear extension cost?
Costs depend on floor area, glazing specification and groundworks. See our house extension cost guide for typical ranges. If your plans also reach into the alley beside the kitchen, our guide to budgeting for a kitchen side infill sets out separate figures.
Will a rear extension make my kitchen dark?
Only if the design does not account for it. ArchEvolve models daylight and rooflight positioning at concept stage specifically to avoid the dark, boxed-in middle room that poorly designed rear extensions often create.
Can a rear extension be combined with a side return?
Yes, this is one of the most popular combinations for terraced and semi-detached properties, and is covered by our side return extension service.
What is included in ArchEvolve's rear extension service?
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.
Which areas does ArchEvolve design rear extensions in?
ArchEvolve covers West Sussex, East Sussex and Surrey, including Worthing, Horsham, Chichester, Crawley, Guildford and Brighton, with a free initial consultation offered throughout the region.
Frequently Asked Questions
Start Your Rear Extension Design Today
Free initial consultation for homeowners across Sussex and Surrey. Get in touch to discuss your rear extension.
