How Much Value Can a House Extension Add to My Property in the UK?

At SGS Building & Carpentry, we’ve helped homeowners across Fordingbridge, the New Forest, and surrounding areas enhance their homes through high-quality extensions that not only meet their lifestyle needs but also offer impressive returns on investment.

In this post, we’ll explore the value of a house extension in the UK, the types of extensions that offer the best ROI, and how to maximise your investment.

What’s the Average Value a House Extension Can Add?

According to recent studies:

• A single-storey kitchen extension can add up to 15% to the value of your home.

• A double-storey extension can increase value by 20-25%, especially when adding an extra bedroom or bathroom.

• A well-designed rear extension can add £30,000-£50,000, depending on your location, layout, and finish.

Which Types of Extensions Add the Most Value?

✅ Kitchen Extensions

Extending your kitchen - especially into a light-filled, open-plan space - is one of the most popular and profitable home improvements in the UK. Modern families love social kitchen-diner layouts, and estate agents know it.

✅ Loft Conversions and Dormer Extensions

Adding a bedroom or home office via a loft conversion often delivers excellent ROI. If it includes an en-suite, the value jumps even higher.

✅ Double-Storey Side or Rear Extensions

Although these cost more, they double your usable space and significantly increase your home’s marketability, particularly in areas where square footage is at a premium.

✅ Garden Rooms and Garden Offices

While not usually counted in official square footage, bespoke garden rooms offer huge lifestyle appeal - particularly in the age of remote work. Many buyers are actively looking for properties with dedicated work-from-home space. To find out more about our Bespoke build Garden rooms and Garden offices, click here

Examples from SGS Building and Carpentry Projects

1. Modern rear extension in Hampshire - Added 22m² of space, transforming a cramped kitchen into a spacious kitchen-diner with skylights and bifold doors. Estimated property value increase: £45,000.

2. Double-storey side extension in Fordingbridge, included an additional bedroom and utility room. Estimated ROI: 18-20% increase in home value.

3. Bespoke garden office built in Dorset, While not counted in traditional valuation, this added huge buyer appeal and helped a homeowner sell above asking price. For more information on our Bespoke built Garden Rooms and Garden offices Click here.

   
   

How SGS Help Maximise Your Investment

At SGS Building & Carpentry, we understand that a home extension is both a lifestyle decision and a financial investment. Our experienced team works with you to design and deliver high-quality, custom extensions that:

• Maximise natural light and usable space

• Integrate seamlessly with your existing home

• Follow building regulations and planning rules

• Deliver long-term value and comfort

We’re here to guide you every step of the way — from concept and planning to the final finishing touches.

Final Thoughts: Is a Home Extension Worth It?

If you're asking "How much value can a house extension add to my property in the UK?" - the answer depends on your location, the quality of the build, and the type of extension. But in most cases, the ROI is significant - both in financial and lifestyle terms.

Whether you’re planning to stay put or preparing to sell, a well-designed extension by SGS Building & Carpentry is a smart way to invest in your home’s future.

👉 Ready to explore your options? Get in touch with us today — let’s talk about your extension plans!

Click here to get in touch

SGS Build — Building spaces that fit your life.

Serving Fordingbridge, the New Forest, Dorset, and surrounding areas.