If your home is starting to feel a little cramped, or you’ve simply outgrown your space but love your location, a house extension could be the perfect solution. Whether you’re dreaming of a spacious open-plan kitchen, an extra bedroom, or a relaxing garden room, extending your home is a fantastic way to add both space and value.
But one of the first questions we’re often asked at J&K Developments is:
“How much does it cost to build an extension?”
While the honest answer is “it depends”, we’ve pulled together some realistic figures and guidance to help you get a clear idea of what to expect – and how we can support you from start to finish.
🧱 Typical Extension Costs in Derby, Derbyshire & Staffordshire
As a general guide, you can expect to pay between £1,800 – £2,800 per square metre for a single-storey extension, and £2,200 – £3,500 per square metre for a two-storey extension.
This range can vary depending on the following:
The size of your extension
The complexity of the build
Your choice of materials and finishes
Access to the property
Any structural or groundworks required
Planning permission and building regulations
🔨 What Type of Extension Are You Planning?
Here’s a quick look at some typical extension types and estimated starting costs:
| Type of Extension | Typical Cost Range |
|---|---|
| Single-storey rear extension (20m²) | £36,000 – £56,000+ |
| Two-storey side or rear extension (40m²) | £88,000 – £140,000+ |
| Wraparound extension | £90,000 – £160,000+ |
| Garage conversion | £15,000 – £30,000+ |
| Loft conversion | £40,000 – £70,000+ |
| Kitchen extension with fittings | £50,000 – £100,000+ |
These are ballpark figures – we always provide a fully itemised quote once we understand your project.
🏠 Why Work with J&K Developments?
We’re a family-run building company based in Derby, trusted across Derbyshire and Staffordshire for delivering high-quality extensions with professionalism and care.
Here’s how we make the process simple and stress-free:
✔️ Free consultation with our Director to understand your goals and budget
✔️ Collaborative design process with our trusted architects
✔️ Planning support – we deal with the local authorities so you don’t have to
✔️ Transparent, itemised quotes – no surprises, just clear pricing
✔️ Seamless build process – our experienced team handles every detail
✔️ Aftercare and support – we’re here long after the work is done
📋 Other Costs to Consider
Don’t forget to factor in:
Architectural drawings and planning application fees
Structural engineer costs (if required)
VAT – most residential extensions are subject to 20% VAT
Finishing touches – kitchens, flooring, bathrooms, lighting, etc.
💡 Thinking About an Extension? Let’s Talk!
An extension is a big investment, but when it’s done right, it can completely transform the way you live in your home. At J&K Developments, we’re here to guide you every step of the way — from concept to completion.
📞 Contact us today to book your free consultation and get a detailed, personalised quote for your extension. Let’s turn your ideas into a space you’ll love for years to come.
