How Much Does a House Extension Cost in Milton Keynes? (2026 Guide)

A single-storey rear extension in Milton Keynes typically costs £40,000–£60,000 in 2026, based on a standard finish at £2,750–£3,050 per square metre. Double-storey extensions run £80,000–£150,000, wraparound extensions £55,000–£80,000, and loft conversions £45,000–£75,000. Your final figure depends on size, site access, finish level and design, use our free calculator for a price based on your exact property.

These figures come from AL-Haitham's 2026 cost calculator, which is powered by live Building Cost Information Service (BCIS) data and HM Land Registry values, with regional multipliers applied for your Milton Keynes postcode. Below is the full breakdown

what you'll pay by extension type, what drives the number up or down, whether you'll need planning permission, and how to get an accurate figure for your own home.

Milton Keynes extension costs at a glance (2026)

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla euismod condimentum felis vitae efficitur. Sed vel dictum quam, at blandit leo.