Thinking about a bigger kitchen, a sunlit home office, or an extra bedroom? You’re not alone. In the UK, adding an extension remains one of the top ways to make your property work for you, not just in space, but also in long-term value. But just how much can a home extension add value right now? 

Recent studies show that expanding your property could boost its worth by as much as 20% in 2025, especially for the right type of space and in the right location.

Let’s take a straightforward look at why more homeowners across the UK (from London to Manchester, and beyond) are extending, and how you can make smart home improvement investments that deliver a real return.

Why Homeowners Love Extensions in 2025

Home has become more than just “where you live.” It’s an office, a gym, a place for family and friends. When your needs change, it’s often cheaper and less stressful to expand what you have, rather than move.

That’s where property value comes in. Not only do you get more usable space, but you often boost your equity for the future. Whether it’s a single-storey, a wraparound design, or a clever loft conversion, the extension ROI in 2025 is making headlines across the UK property market.

1. Add an Extra Bedroom (Especially With an Ensuite)

Adding a bedroom, especially with a bathroom, is one of the fastest ways to see how home extension add value property value increase. Buyers love the flexibility of extra bedrooms. Imagine a new baby, growing kids, or hosting visitors. In 2025, this upgrade could increase your property value by up to 10-12%.

Tip: Go for an ensuite if possible. This appeals to buyers looking for more comfort and privacy.

2. Convert the Loft Into a Liveable Space

Loft conversions remain at the top for the most significant extension ROI. From a new master bedroom to a bright home office, creative use of the loft can raise the value of your property by up to 20%. The bonus? You’re using space that’s already there.

3. Build an Open-Plan Kitchen and Living Area

Open-plan spaces are a favourite for families,  and an open, modern kitchen blends seamlessly with dining or lounging spots. This change can increase property value by 10-15%. Plus, it’s perfect for entertaining or keeping an eye on the kids while cooking.

Tip: Use islands or breakfast bars for style and functionality.

4. Design a Smart Home Office

More people are working from home in 2025. Adding a dedicated office, separate from bedrooms and living rooms, makes your property stand out. Home buyers now search for spaces that fit a flexible working lifestyle, and even a small office nook can boost extension ROI.

Tip: Soundproofing and plenty of light go a long way to make it appealing.

5. Expand With a Double-Storey Extension

If you have the land, a double-storey extension is a smart home improvement investment. This gives you new space upstairs and down, think extra bedrooms, big family bathrooms, or a ground-floor utility room. Double-storey extensions can bring a property value increase of 10–12%.

6. Add a Sunroom or Conservatory

Natural light never goes out of style. A sunroom, orangery, or quality conservatory creates an all-weather living space that connects house and garden. While not as impactful as a bedroom or loft, a good-sized sunroom can push up your property value by 5–7%, sometimes more, in locations where gardens are prized.

Tip: Choose energy-efficient glass and sound insulation to use year-round.

7. Upgrade or Extend Your Kitchen

Kitchen extensions remain hugely popular in UK homes. Modern buyers want bright, open kitchens ready for family, work, and entertaining. A full extension can mean space for a dining table, more storage, or even a separate utility room, increasing your home’s appeal by 10–15%.

8. Garage Conversions for Extra Living Space

Got a garage you rarely use? Converting it to a bedroom, gym, playroom, or office is a quick win for both families and future buyers. In growing areas like suburbs around London or Midlands cities, garage conversions are a home extension add value property value increases, often bumping up property values by 10%.

9. Add a Utility Room or Extra Bathroom

A utility room may not sound glamorous, but buyers appreciate dedicated laundry space. In 2025, with more focus on work-from-home and busy families, an extra bathroom or utility room can be a deal-maker.

10. Create a Flexible, Multi-Use Space

Perhaps your property has a unique layout: consider a partitioned extension for a hobby room, guest suite, or a mix of work and relaxation space. This is especially effective in homes with odd-shaped plots or older terraced properties in UK cities.

Tip: Sliding or folding doors create spaces you can open up or close off as needed.

What Determines the ROI of a Home Extension?

• Location: Return is higher in fast-growing or high-demand regions (London, Bristol, Manchester).

• Type & Quality: Loft conversions, extra bedrooms, and large kitchens pay off more than small, simple add-ons.

• Finishes: Modern, energy-efficient finishes add appeal.

• Permission & Building Regs: Proper approvals and inspections ensure buyers feel secure.

• Market conditions: Keep an eye on property trends in your area to maximise ROI.

Things to Watch: Planning, Costs, and Returns

Building an extension isn’t stress-free. It can take 10–18 weeks for completion, with average UK costs around £40,000 (but much higher, depending on size, type, and finish). Always factor in:

• Planning permission (check local rules)

• Party wall agreements

• Possible disruption and alternative living space during construction

A professional assessment and design help you avoid big mistakes and maximise your returns in the local property market.

FAQ: Home Extensions and Your Property Value in 2025

Q: How do I know if my extension will add value?

Check if your type of extension (bedroom, kitchen, office) is in demand in your area. Professional design and finish can make a massive difference in extension ROI.

Q: How much should I budget for a home extension to add value?

Budget anywhere from £40,000 upwards for a decent single-story extension. Double-storey or high-end projects can cost much more.

Q: Is planning permission always required?

Not always, but most structural extensions do require some form of application or inspection. Check local council guidelines before you start.

Q: How fast can I see a return on my investment?

Some extensions offer instant property value increase, but the most substantial return comes if you hold the property for several years during a strong housing market.

Q: What’s the smartest kind of extension right now?

Loft conversions, open-plan kitchens, and extra bedrooms lead the way for the best home improvement investment in the UK market.

Conclusion

A home extension doesn’t just add space; it can be the single smartest property move you make in 2025. With the right design, proper planning, and a clear eye on location, your extension can bring years of comfort, flexibility, and impressive returns when it’s time to sell. As the UK market grows and changes, projects that add real function, such as bedrooms, kitchens, and offices, remain strong bets for boosting your home’s worth.

To get the best insight and outcomes for your own plans, seek detailed, up-to-date advice before building. At Buildworth.uk, the goal is simple: empower you to make smart home improvement investments, so your property’s value continues to rise year after year.