House Extensions in Brighton, Worthing and West Sussex

Create the Space You Need

Need more room without the upheaval of moving? Apex Lofts & Construction designs and builds house extensions for homeowners in Brighton, Worthing and across West Sussex. Whether it is an open-plan kitchen, a home office or an extra bedroom for a growing family, we help you get more from the home you already have.

Expand Your Home with a Bespoke Extension

Designed for Your Lifestyle and Future Plans

Every family’s needs are different, and your home should reflect that. Our team works closely with you to design an extension that enhances the way you live, today and tomorrow. From creating sociable kitchen-diners to building quiet corners for remote working or relaxation, we tailor every detail around your goals.

Add Space and Style to Your Home

A well-planned extension gives you the extra room you need without leaving the area you know. Whether you are extending outwards, upwards or both, we make sure the new space ties in with the existing structure, so it looks like part of the house rather than an add-on.

Bedroom with a double bed beneath a large window

What Our Clients Say

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Charlotte Taylor
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⭐️⭐️⭐️⭐️⭐️ Really pleased with our new garden office and the finished result. The team did a great job and we’re very happy with the quality of the work and how the space has turned out. As with most building projects, there were a couple of things that needed resolving along the way, but everything was handled professionally and the team worked with us to make sure we were happy with the outcome. They were friendly, helpful and responsive throughout, and clearly took pride in getting everything right. We absolutely love the finished space and wouldn’t hesitate to recommend them.
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Christophe profile picture
Christophe
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We used Apex to carry out a full house refurbishment with loft conversion. They were very professional throughout the whole process delivered a high quality project. Would highly recommend.
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Kakurusi Kasereka profile picture
Kakurusi Kasereka
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Cet en forgent qu'on devient forgeron.
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rosie stowell profile picture
rosie stowell
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Apex did our loft conversion this year and we would definitely recommend them. They were really hard-working, efficient, respectful and produced a great final finish. We also appreciated being kept well informed as the job progressed. Thanks to all the guys at Apex, great job.
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Joseph Harrington
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Loft conversion. Very happy with the all the work done. On time on budget and really good to deal with theoughout.
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Jamie Pugh profile picture
Jamie Pugh
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Apex were great to work with and we are really pleased that we chose them to do our loft conversion. Easy communication and clear payment schedule. Carpenters were particularly great. No question or query from us too much of a problem. They were great to work with a would definitely recommend them. We’re really happy with our new loft.
Loft room with roof windows and a sofa, opening onto the landing

Design and Build House Extensions in Worthing and Brighton

Apex is based in Worthing and builds house extensions across West Sussex and into Brighton and Hove. We run each project as design and build, so one team takes you from the first site visit through to handover, with trusted partners brought in where the design needs them.

On the design side, we work with trusted architectural partners to produce your technical drawings, and we can prepare and submit a planning application or a Lawful Development Certificate on your behalf. If you already have plans, we can build from those instead.

Every extension is built to current Building Regulations and run under CDM 2015. Planning rules vary from one property to the next, so please confirm the planning position for your home with your local council (Brighton & Hove City Council or Worthing Borough Council, for example) and speak to a surveyor about any Party Wall requirements before work starts.

Types of Extensions We Build

Rear Extensions

Ideal for expanding kitchens or living areas into the garden, rear extensions are a popular way to enhance your ground floor living space.

Side Return Extensions

A side return extension builds into the narrow strip beside the house, opening up the interior and creating a brighter, more spacious layout.

Wraparound Extensions

A combination of rear and side extensions, offering maximum space and flexibility. Perfect for open-plan kitchen-diners or multi-functional family areas.

Double-Storey Extensions

Need space upstairs as well? A double-storey extension adds bedrooms, bathrooms or a home office on both floors, making the most of the garden space you build on.

Kitchen & Living Room Extensions

Whether you’re after a sociable hub for cooking and entertaining or a relaxed lounge area, we design and build extensions that transform how you use your home.

Why Choose Apex?

We Maximise Your Property’s Potential

From loft conversions to full refurbishments, we help you make the most of your home’s space, flow and value, with solutions designed around how you live.

Reliable, Experienced & Local

With decades of hands-on experience and a West Sussex base, we’ve transformed countless homes and commercial spaces throughout the region.

Craftsmanship You Can Trust

Our in-house team and specialist partners deliver high-quality results backed by a commitment to compliance, attention to detail, and long-term performance.

Our House Extension Process

Free Site Survey & Expert Consultation

We begin with a no-obligation visit to assess your property and discuss your ideas. We’ll help you explore the best options based on your budget, layout, and planning constraints.

Architectural Design & Planning Submission

If you need drawings, we work with trusted architectural partners to design your extension, and we can prepare and submit the planning application or Lawful Development Certificate on your behalf.

Clear Scope of Works & Transparent Quoting

You’ll receive a detailed quote and schedule of works, with no hidden extras. Every aspect of your extension is accounted for, from groundwork and structure to electrics, heating and finishing touches.

Build Phase with Dedicated Project Management

Your dedicated project manager will oversee the entire build and keep you informed throughout, so you always know what is happening next.

Final Inspections, Snagging & Handover

We carry out full quality checks and snagging before handover, ensuring everything meets specification, safety standards and your satisfaction.

Ongoing Support & Aftercare

Our relationship doesn’t end when the build does. We’re on hand for ongoing support and aftercare should you need any follow-up or maintenance advice.

Start Planning Your Extension Today

Book a Free Consultation with Apex

If you’re ready to expand your home, talk to the team at Apex Lofts & Construction. From the initial design right through to the final coat of paint, we’ll guide you every step of the way.

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Frequently Asked Questions

Not always. Many single-storey extensions fall under permitted development rights if they stay within set size and height limits, but listed buildings, conservation areas and larger or double-storey designs often need full planning permission. We can prepare and submit the planning application, or a Lawful Development Certificate to confirm a permitted development build, on your behalf. The planning position always depends on your property, so please confirm it with your local council before work starts.

It depends on the size of the extension, the design and the planning route, so we do not give a standard figure. We set out a realistic programme for your project once the design is agreed, and keep you updated throughout the build.

A well-designed extension that improves the layout, or adds space buyers look for such as an open-plan kitchen or an extra bedroom, can make a home more appealing when you come to sell. How much it adds depends on your property and the local market, so a local estate agent is the best person to ask.

In most cases, yes. We work to minimise disruption wherever possible, and many of our clients remain at home throughout the project. For larger or more invasive works, we’ll discuss practical arrangements during the planning stage.

Absolutely. We carefully match materials, finishes, and architectural details to ensure your new extension looks like a natural part of your home.

Yes. Apex is based in Worthing and builds extensions across the town and its neighbouring areas, as well as in Brighton and Hove and the towns along the coast in between. The first step is a free site survey at your home, where we look at the options with you and talk you through the planning route.

Yes. Every extension is built to meet Building Regulations, covering structure, insulation, fire safety, ventilation and electrics. Building Control checks the work at key stages, and we make sure it is ready for each inspection.

Yes. Apex offers a design and build service. We work with trusted architectural partners on the design and technical drawings, and we can prepare and submit a planning application or Lawful Development Certificate on your behalf. If you already have drawings, we can build from those. Please discuss any Party Wall requirements with a surveyor before the build starts.

Yes. All work is backed by appropriate guarantees, and we provide full aftercare following completion. We’re always on hand to answer questions or resolve any issues, even after the project is finished.

Every extension is unique, and costs vary based on the scale of the build, the materials used, and the level of customisation involved. After an initial site visit and consultation, we’ll provide you with a detailed, transparent quote tailored to your project, with no hidden extras.