How Much Does an Extension Really Cost in 2024?

One of the most common questions we get is: "How much will an extension cost?" The answer is always: "It depends." But that's not helpful when you're trying to budget.

The "Per Square Metre" Rule

As a very rough guide for 2024 in the North West:

• Basic Shell: £1,800 - £2,200 per m²
• Standard Finish: £2,200 - £2,800 per m²
• High Spec: £3,000+ per m²

So, a standard 4m x 5m (20m²) extension would likely start at around £44,000 for the build alone.

Don't Forget the "Extras"

The build cost is just part of the picture. You must also factor in:

• VAT (20%): This is huge. On a £50k build, that's another £10k.
• Professional Fees: Architects, structural engineers, building control (allow 10-15%).
• Finishes: Kitchens, flooring, and decorating are often extra to the builder's quote.

At Build Clarity, we provide detailed cost breakdowns so you can see exactly where your money is going before you start digging foundations.