A Complete Guide to Home Extensions in the UK: Costs, Timelines & Types | Sketchpad

Thinking of extending your home in the UK? Whether you're craving more space, boosting your property’s value, or reimagining your home's layout, a house extension can be a smart investment. At Sketchpad, we specialise in architectural design and planning for all types of extensions — and we’re here to make the process smooth from concept to completion.

In this article, we break down the most popular types of home extensions in the UK, including typical build costs and timelines. Ready to plan your dream extension? Visit www.sketch-pad.co.uk to get started with our expert team.

1. Rear Extensions

Rear extensions are among the most popular types of home extensions in the UK. These extend from the back of the house into the garden space and are ideal for expanding kitchens, creating open-plan living areas, or adding dining rooms.

Typical Cost: £1,800 – £3,000 per m²
Build Time: 10 – 14 weeks

At Sketchpad, we guide homeowners through every step of the rear extension journey — from planning permission and building regulations to finding trusted contractors.

2. Side Return Extensions

Perfect for Victorian and Edwardian terraced homes, side return extensions utilise the often underused alleyway beside the house. This type of extension can completely transform your kitchen and dining area.

Typical Cost: £2,000 – £3,200 per m²
Build Time: 8 – 12 weeks

Want to see what's possible with your side return? Get in touch with Sketchpad for a tailored consultation or browse our past projects at www.sketch-pad.co.uk.

3. Wraparound Extensions

A wraparound extension combines a rear and side return extension to form an L-shape, creating significant additional space. This is perfect for families looking to add multifunctional open-plan zones.

Typical Cost: £2,200 – £3,500 per m²
Build Time: 12 – 16 weeks

Because of the complexity, wraparound extensions require careful design and structural planning. At Sketchpad, our team ensures everything from lighting to layout flows seamlessly.

4. Double Storey Extensions

If you're looking to maximise vertical and horizontal space, a double storey extension could be your best option. These extensions are ideal for adding extra bedrooms, bathrooms, or home offices.

Typical Cost: £2,000 – £3,000 per m² (cheaper per m² than single-storey extensions)
Build Time: 14 – 20 weeks

A double-storey project often needs full planning permission and complex structural calculations — services that Sketchpad can fully manage on your behalf.

5. Dormer Loft Conversions

While technically a loft conversion, dormer extensions are a smart way to add usable floor area to the top of your home. These are perfect for additional bedrooms or home offices.

Typical Cost: £1,500 – £2,500 per m²
Build Time: 6 – 10 weeks

At Sketchpad, we offer 3D modelling and planning submission services to help visualise your dormer loft conversion before a single beam is lifted.

6. Garage Conversions

Converting your garage is one of the most cost-effective ways to extend your home. It’s ideal for creating a home gym, playroom, or even a self-contained annex.

Typical Cost: £1,000 – £2,000 per m²
Build Time: 4 – 8 weeks

Sketchpad can help ensure the conversion meets building regulations while unlocking the true potential of your underused garage space.

How Sketchpad Helps Bring Your Vision to Life

At Sketchpad, we don’t just design buildings — we create homes that enhance how you live. Our full architectural service includes:

• Initial consultation

• Planning permission drawings

• Building regulations compliance

• 3D visualisations

• Contractor connections

We’re proud to help homeowners across the UK bring their ideas to life with innovative, practical, and value-boosting home extensions. Visit www.sketch-pad.co.uk to explore our portfolio or book a free consultation.

Final Thoughts

Choosing the right type of home extension depends on your space, goals, and budget. Whether it’s a modest side return or a grand double-storey transformation, Sketchpad is your trusted partner in architectural design and planning.

Get in touch with us today through www.sketch-pad.co.uk to begin your home extension journey.