House Extensions in West Sussex

Create the Space You Need

Need more room to grow, entertain, or simply breathe? A professionally built extension by Apex Lofts & Construction allows you to reimagine your home, without the stress of moving. Whether it’s an open-plan kitchen, a home office, or an extra bedroom for a growing family, we help you make the most of the space 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, Style and Value to Your Property

A well-planned extension not only gives you the extra room you need but can also increase your home’s market value significantly. Whether you’re extending outwards, upwards, or both, we ensure your new space blends seamlessly with the existing structure, boosting kerb appeal and resale value.

What Our Clients Say

Expert Home Extensions by Apex Lofts & Construction

At Apex, we’ve been helping homeowners across West Sussex and the South East transform their properties for decades. With over 50 years of combined experience, our in-house team and trusted partners manage everything from design and planning through to the final handover.

We understand that extending your home is a major decision. That’s why we offer a fully managed, end-to-end service that removes the stress from the process. Whether you already have architectural plans or are starting from scratch, we can support you at every step with expert advice, quality workmanship, and transparent communication.

We also ensure that all work complies with current Building Regulations and CDM 2015, meaning your new extension won’t just look the part, it will be built to last.

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

Often used in Victorian or Edwardian terraced homes, side return extensions make clever use of narrow alleyways to open up interiors and create brighter, more spacious layouts.

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? Double-storey extensions add serious value by creating additional bedrooms, bathrooms, or offices, while maintaining your garden footprint.

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 help with drawings or planning permission, we work with experienced architects to bring your ideas to life and handle all local authority submissions 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 to ensure everything stays on time, on budget and to the highest standards, keeping you informed throughout.

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.

Frequently Asked Questions

Not always. Many single-storey extensions fall under permitted development rights, especially if they meet specific size and height limits. However, if your property is listed, in a conservation area, or you’re planning a double-storey extension, planning permission may be required. We’ll advise you during the consultation and can handle the full application process if needed.

A typical single-storey extension takes around 10–12 weeks from the start of construction, depending on the complexity and weather conditions. We’ll give you a realistic timeline during the planning stage and keep you updated throughout the build.

Yes. A well-designed extension can add up to 20–25% to your property’s market value, especially if it improves functionality, layout, or creates desirable spaces like open-plan kitchens or additional bedrooms.

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.

We offer a wide range of extensions including:

  • Rear extensions

  • Side return extensions

  • Wraparound extensions

  • Double-storey extensions

  • Kitchen and lounge extensions

Our team will help you choose the best option for your property and goals.

Yes. All our work complies fully with Building Regulations – covering structure, insulation, fire safety, ventilation, electrics and more. We also manage any required inspections with building control.

Yes. We offer a complete design and build service. Whether you’re starting with a rough idea or already have architectural drawings, we’ll support you with expert design advice, planning submissions, and structural engineering as needed.

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.