House Extensions Chiswick | Planning, Costs and Design Tips

House extensions Chiswick are a great option if you need more space but don’t want to move. Whether you’re thinking about a bigger kitchen, an extra bedroom, or even a home office, extending your house can make your home more comfortable and more valuable. Many people in Chiswick choose to build an extension to stay in the area they love while still upgrading their living space.

Why Homeowners in Chiswick Are Choosing to Extend

More and more people are choosing house extensions in Chiswick instead of moving to a new home. There are a few simple reasons for that.

First, moving house in London can be stressful and expensive. You have to deal with estate agents, legal fees, stamp duty, and all the hassle of packing and relocating. With an extension, you stay in the same place — close to your school, work, and neighbours — while making your home work better for you.

Second, house prices in Chiswick are high. By extending, you can increase the value of your home significantly. A well-planned extension can boost your property’s value by up to 20% or more, depending on the size and quality of the work.

Finally, families grow and needs change. Whether you need a new room for a baby, a home office for remote work, or more open space for daily living, a house extension gives you flexibility to shape your home around your lifestyle.

Popular Types of House Extensions in Chiswick

If you’re planning a house extension in Chiswick, the first step is choosing the right type of extension for your home and your goals. Here are some of the most popular options:

Rear Extension

A rear extension adds space at the back of your home, often opening up the kitchen or living area. It’s perfect if you want an open-plan layout or more room to entertain.

Side Return Extension

Many Victorian and Edwardian homes in Chiswick have a narrow alleyway along the side. A side return extension fills that unused space, giving you extra width in your kitchen or dining room.

Wraparound Extension

This combines both a rear and side return extension to form an L-shape. It creates a large open-plan space and is ideal for families who want a spacious kitchen-diner and lots of natural light.

Loft Conversion

A loft conversion turns your attic into a usable room — like a bedroom, study, or even a small flat. It’s a great way to add living space without taking away garden space.

Garage Conversion

If you don’t use your garage for parking, why not turn it into a home office, gym, or guest room? It’s a cost-effective way to add an extra room with minimal structural work.

Each extension type offers different benefits. The right one depends on your property layout, your budget, and how you want to use the space.

To explore what’s possible, check out our house extension services ➝

Do You Need Planning Permission in Chiswick?

One of the most common questions we hear is: “Do I need planning permission for my extension?” The answer depends on the size and type of the extension — and where in Chiswick your property is located.

In many cases, house extensions in Chiswick fall under something called Permitted Development (PD). This means you don’t need full planning permission if your extension meets certain rules (like size limits, height, and how far it extends).

But Chiswick has several conservation areas, especially around Bedford Park, Strand-on-the-Green, and Turnham Green. If your home is in a conservation area, you might face more restrictions. You may also need permission if:

Your extension is two storeys or higher
You want to build very close to your neighbour’s boundary
You’re making changes to the front of the property

💡 Tip: Always check with your local council (Hounslow or Ealing) and work with a builder who understands local regulations. We’ve helped many Chiswick homeowners get their plans approved without stress.

Learn more about how we work locally on our Chiswick service page ➝

How Much Does a House Extension in Chiswick Cost?

One of the first things homeowners ask is: “How much will it cost?” The truth is, the price of a house extension in Chiswick can vary based on a few key factors, like the size of the extension, the type of work, and the quality of the materials used.

Here’s a general idea of what you can expect:

Type of Extension	Average Cost Range (2025)
Rear Single Storey	£1,800 – £2,500 per m²
Side Return	£1,700 – £2,400 per m²
Wraparound Extension	£55,000 – £85,000+
Loft Conversion	£35,000 – £60,000
Garage Conversion	£12,000 – £25,000

These prices usually include building work, basic finishes, and project management. But don’t forget to budget for:

Architect or structural engineer fees
Planning permission (if required)
Party wall agreements (if you share a wall with a neighbour)
Interior fittings (like kitchens or bathrooms)
VAT (usually 20%)

💡 A smart extension doesn’t just add space — it can increase the value of your home by 15–20% or more, depending on the area and quality of finish.

We always provide a detailed quote so you know exactly what you’re paying for. Get in touch with our team ➝ for a personalised estimate based on your ideas.

Smart Design Ideas for Chiswick Extensions

Design plays a big role in how your extension will look, feel, and function. When planning a house extension in Chiswick, it’s not just about adding space, it’s about making that space work beautifully with your existing home.

Here are a few smart design tips to consider:

Maximise Natural Light

Use bifold or sliding glass doors to open your space to the garden. Add skylights or a roof lantern to bring in light from above, especially if you’re building a side return or wraparound extension.

Match Old with New

Chiswick has many period homes, so it’s important your extension fits the style. Use matching bricks or paint finishes to keep the look consistent, while still adding a modern twist inside.

Open Plan Living

Removing internal walls can make your new space feel even bigger. Open-plan kitchens and living areas are one of the most popular choices for growing families.

Upgrade Comfort

Consider adding underfloor heating, better insulation, or soundproofing to make your space more comfortable all year round.

Think Sustainable

Eco-friendly materials, good insulation, and energy-efficient windows can save you money in the long term — and make your home greener.

Every home is different, which is why we offer custom design solutions tailored to your needs, lifestyle, and budget. We’ll help you turn ideas into real plans — and real plans into a stunning new space.

Working With the Right Contractor

Hiring the right team is crucial. At Iron Construction, we’ve worked with dozens of homeowners across Chiswick, delivering high-quality home extensions that match both design vision and budget.

What you get when working with us:

End-to-end project management
Clear timelines and pricing
Help with planning applications
High-quality materials and workmanship
Transparent communication throughout

FAQs About House Extensions in Chiswick

Q: How long does a typical extension take in Chiswick?
A: Most single-storey extensions take 10–14 weeks. Loft conversions can be faster, around 6–8 weeks.

Q: Do I need an architect?
A: Yes, especially for larger or more complex projects. We can recommend trusted local architects we regularly work with.

Q: What’s the biggest challenge in Chiswick extensions?
A: Navigating local planning regulations and ensuring designs suit older properties. We specialize in this!

Conclusion

If you’re considering a house extension in Chiswick, now’s a great time to start planning. With rising property values and space at a premium, extensions offer both lifestyle improvements and financial benefits. Whether it’s a rear kitchen extension or a loft conversion, proper planning and execution make all the difference.

💡 Want to explore your extension ideas with a local expert? Get in touch with our Chiswick team ➝

How to Plan a House Extension in Chiswick: Permits, Costs, and Design Tips