🧱 Extensions Don’t Always Add Up: What Actually Increases Your Home’s Value?

Read time: 4 minutes…

A few days ago, I stopped by a friend’s house—he was busy painting his newly built garage. As we caught up, he mentioned how they'd been extending and improving their home for two years. As a finance director, he knew that not every penny invested would show up in the home’s value. And right he was.

That conversation inspired this article, because:

1. Too often we assume:

   current value + cost of the extension = new value

   
   ❌ It’s rarely that simple.

2. Being aware of point #1 above doesn’t mean you know how to assess added value accurately.

3. If you’re planning work, I’d like to share some tips before you get started on how to get both enjoyment and long-term value.

What Actually Drives Home Value?

There’s a lot to unpack. Let’s start with the basics.

At its core, your home’s value is shaped by:

• Location (you can’t change this!)

• Usable square footage

• Condition, style and presentation

And here’s the secret: the market defines value—not the homeowner or agent. We can only estimate a price range using comparable sales, £/sq ft, and broader trends.

Always use a combination of indicators—never just one (like £/sq ft)—as each metric, taken in isolation, has its flaws. For example:

• Average £/sq ft values in an area can be significantly skewed by outliers, such as social housing or a mega-mansion on your street.

• House price indices (like Nationwide’s calculator: link) show the average percentage change over time, but don’t reflect the context of your original purchase. You might have secured a deal on a distressed sale or bought new at a year-end discount—both of which distort the true starting value.

• Property measurements in England aren’t regulated. This means the same home can appear with different square footage across multiple listings, depending on the agent. What truly matters is usable living space, not just numbers on paper.

• Prices of comparable properties sold in the area provide a valuable piece of information for the valuation exercise. However, bear in mind it is a lagging indicator, providing measurement of what happened in the past. To best predict the future, the evolution of the conditions—economy, trends, demand/offer—must be taken into account.

• Understanding local demand and buyer behaviour requires homework. You need to know who your most likely buyer is and what they value—because that’s what ultimately determines price. A personalised market report will provide usable data and actionable insights.

Know Your Buyer—Even If You're Not Selling

Why think about buyers if you're not selling? Because your future sale starts today.

If you’re about to spend £50k improving your home, shouldn’t you know who it’s likely to appeal to? That helps you choose finishes, layouts, and features that boost perceived value instead of accidentally limiting it.

Start by asking:

• Who were you when you bought this house?

• What did you need then?

• Have the area or buyer demographics changed?

From there, you can define a profile and make smart decisions. If your ideal buyer is a professional family with young children, a glass-walled home office won’t appeal. But a well-designed, multi-use loft might.

So, What Works and What Doesn’t?

Here’s a look at the most common projects and their typical impact on value:

✅ Extensions (Done Right)

More square footage usually adds value—but only when the space makes sense and feels cohesive.

💡 Loft conversions, garage conversions, and single-storey rear extensions tend to perform well—especially when they enhance how the home flows.

🚫 But beware of layouts that only suit you (e.g. a second kitchen just for the dogs, kitchen and dining rooms being two rooms apart).

🛑 Conservatories can be tricky: cheaper to build, yes, but often impractical, too hot/cold, and not really "living space."

Main benefit: directly increases property value, best indicator is the average £/sq ft

🛠️ Upgrading the Standard

Bringing a home up to the local average (or slightly above it) can increase its perceived value—and help it stand out.

But there’s a ceiling. Putting £50k marble bathrooms in a street of £350k homes? You won’t see that money back.

Stick to improvements that:

• Add modern convenience

• Improve light, flow, and comfort

• Keep you in line with area expectations

Main benefit: increases property value for a subset of homebuyers, most relevant indicator is the price of similar properties sold in the area

🔧 Renovating Core Spaces

Renovating kitchens and bathrooms rarely boosts the price on their own—buyers expect these to be functional and clean.

But improving them can help sell faster or achieve closer to asking. Reconfigure layouts. Modernise lighting. Make them feel fresh, not flashy.

Main benefit: makes your listing relevant, reduces time to first offer

Pro Tip: Use Smart Staging & Strategy

It’s not just about bricks and mortar. Presenting the lifestyle your home offers—through thoughtful staging, great media, and a pricing strategy tailored to your ideal buyer—will have more impact than a pink render on your front façade. (Trust me. I’ve seen one.)

Final Thoughts

If you're considering an extension or renovation:

🏡 Do it early—so you can enjoy the benefits
🧠 Think like a future buyer
📊 Work with an agent who knows your local market and can provide a realistic plan

Whether you’re planning for the long term or thinking of selling soon, I’d be happy to chat. Book a free consultation or request a local market insight report via [email protected]

🏡 Local Business Spotlight — Connected Architecture

It’s rare to find a good and active listener… someone who will take the conversation beyond the what to get to the why…

If you’re considering an extension or renovation and want more than just extra space — something with vision, flow, and lasting value — I’d love to introduce you to a firm I truly recommend.

Connected Architecture is a Berkshire-based, RIBA-chartered architecture studio known for creating modern, sustainable homes for discerning homeowners and small-scale developers. Whether you’re updating a listed cottage, adding a striking extension, or building from the ground up, their work combines creative thinking with deep respect for context, lifestyle, and the environment.

I’ve had the pleasure of knowing Bronwen, the founder, for almost a year now. In that time, I’ve come to see how much her values mirror mine: client-first service, clear communication, and a commitment to excellence. What sets her apart — beyond the design talent and impressive planning success rate — is the care she puts into really getting to know her clients. What they hoped to solve. How they lived, worked, raised a family — and how a home could better support all of that.

Plus, very relevant fact for Thames Valley homeowners, Bronwen’s studio has worked on listed buildings, new builds and green belt projects.

If you’re thinking of making changes to your home — or simply imagining what might be possible — Bronwen and her team are well worth a conversation.

📍 Learn more: connectedarchitecture.co.uk

✨ Want more homeowner insights like this?
Subscribe to The Prestige Collection newsletter and never miss a tip that could add tens of thousands to your home's value.

P.S. To avoid missing out, here are 2 quick things that really help:

✅ Please reply to this email and say "Hi!"

✅ Please move this email into your main inbox.

These simple actions will ensure future emails land where they should.