House Extensions & Conversions in West Sussex
Thinking about extending your home? JT Builds & Specialised Carpentry delivers high-quality house extensions and conversions across West Sussex — from single-storey kitchen extensions in Storrington to loft conversions in Horsham. With over 100 five-star reviews on Checkatrade, we bring the same care and craftsmanship to every project, whether you’re adding a bedroom, converting a garage, or creating an entirely new living space.
Call us on 01798 879 601 for a free, no-obligation consultation.
Types of Extensions & Conversions We Build
Single-Storey Extensions
The most popular way to expand ground-floor living space. Single-storey extensions are ideal for enlarging a kitchen, adding a utility room, creating an open-plan dining area, or building a home office. We handle everything from foundations and structural steelwork through to roofing, windows, and internal finish.
Double-Storey Extensions
Add space on both floors simultaneously. Double-storey extensions typically give you more usable square footage per pound spent than two separate single-storey projects, and they can dramatically transform the layout and value of a property.
Loft Conversions
Transform unused roof space into a bedroom, en suite, home office, or playroom. We work with Velux, dormer, hip-to-gable, and mansard designs. A loft conversion is one of the most cost-effective ways to add a bedroom without reducing your garden footprint.
Garage Conversions
Convert an integrated or attached garage into a habitable room — extra bedroom, games room, home gym, or study. Garage conversions typically require minimal groundwork and can be completed relatively quickly, making them one of the best-value ways to gain an extra room.
Side & Wrap-Around Extensions
Use the space down the side of your property, often combined with a rear extension to create a full wrap-around. These work particularly well on semi-detached and detached homes and can open up a ground floor completely.
Outbuilding & Annexe Conversions
Convert an existing outbuilding, barn, or large garden structure into a functional annexe, studio, or self-contained living space. We can also advise on the planning considerations around habitable annexes.
Our Build Process
Every project is different, but our process is consistent. We keep things clear, straightforward, and well-managed from first call to final handover.
- Free site consultation — We visit, listen to what you want, and give honest advice about what’s achievable within your budget and timescale.
- Planning advice — We advise on whether your project falls under permitted development rights or needs a planning application, and can work alongside your architect.
- Structural groundwork — Foundations, drainage, and steelwork handled by our team with trusted local structural engineers on hand when needed.
- Build & first fix — Brickwork, roofing, windows, insulation, plastering, and first-fix services, all managed under one contract.
- Finish & handover — We don’t disappear at practical completion. We walk through every detail with you and follow up once you’ve had time to settle in.
Why Choose JT Builds & Specialised Carpentry?
- 100+ five-star Checkatrade reviews from homeowners across West Sussex
- West Sussex based — local knowledge, local contacts, no long-distance call-out costs
- Full project management — you deal with us, not a dozen separate trades
- Transparent quotations — detailed breakdown with no hidden extras
- Experienced with permitted development & planning — we’ve navigated both many times
- Happy to work from architect’s drawings or help you find the right designer
Areas We Cover
We carry out house extensions and conversions across West Sussex, including West Chiltington, Storrington, Pulborough, Billingshurst, Petworth, Steyning, Amberley, Horsham, Worthing, and the surrounding villages. If you’re not sure whether we cover your area, just give us a call — we’re happy to advise.
Frequently Asked Questions
Do I need planning permission for a house extension in West Sussex?
Many extensions fall under Permitted Development rights, so you won’t need a full planning application. This typically covers single-storey rear extensions up to 4m deep (detached) or 3m deep (semi-detached and terraced), and side extensions up to half the width of the original house. Rules vary depending on your property type and location, including whether you’re in a conservation area. We’ll advise you clearly at the consultation stage.
How long does a house extension take?
A standard single-storey extension typically takes 10–16 weeks from groundworks to completion. A double-storey extension or dormer loft conversion is usually 16–24 weeks. We’ll give you a realistic programme before work starts and keep you updated throughout.
What does a house extension cost in West Sussex?
Single-storey extensions typically range from £1,500–£2,200 per square metre depending on specification and groundwork conditions. Loft conversions generally start from £35,000–£50,000. These figures vary significantly based on your specific project — contact us for a detailed, site-specific quotation.
Can you manage building regulations and structural calculations?
Yes. Building regulations approval is required for virtually all extensions and conversions. We can submit a building notice or full plans application on your behalf and liaise with your local authority inspector throughout the build. We work with trusted structural engineers when required.
Do you work with architects and designers?
Absolutely. We regularly work from architect’s drawings and are happy to liaise directly with your designer to ensure the build matches the design intent. If you haven’t yet got drawings, we can point you in the right direction.
Get a Free Quote for Your Extension or Conversion
Ready to start planning? Get in touch for a free, no-obligation consultation at your property.
📞 01798 879 601
✉ info@jtbuildsandsc.co.uk
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