Cost guides
What things actually cost
Published UK cost ranges, cited to named industry sources, not a Homespace Improvements quote. Every figure here carries its source and the date it was checked, so you can judge it for yourself before getting a proper estimate for your own project.
How much does a garage conversion cost?
£625-£3,000 /m²
Published UK ranges for converting a single or double garage.
How much does a loft conversion cost?
£750-£2,500 /m²
Published industry ranges by conversion type, so you can budget sensibly before getting a quote.
How much does a house extension cost?
£1,600-£3,500 /m²
The published UK per-m² rate for a single-storey extension, and what actually moves it.
How much does a two storey extension cost?
£1,350-£3,000 /m²
Published per-m² rates by build quality, and what a typical two-storey extension runs in total.
How much does a party wall surveyor cost?
£900-£1,200
Published UK ranges by project type, for one surveyor and for two.
How much does a garden room cost?
£600-£2,500 /m²
Published UK ranges from a basic self-assembly office to a fully insulated garden room.
How much does planning permission cost?
£548
The current government application fee, and what else typically adds to the cost.
How much does a house renovation cost?
£65,000-£88,000
What we could - and couldn't - find a reliable published figure for.
How much does a kitchen extension cost?
£15,000-£35,000
What a kitchen extension adds on top of a standard extension, and what a typical project costs in total.
How much does a basement conversion cost?
£1,000-£1,800 /m²
Converting an existing cellar and excavating a new basement are different jobs at very different rates - published UK ranges for both.
How much does a dormer loft conversion cost?
£1,500-£2,500 /m²
The published UK average for a dormer conversion specifically, alongside our general loft conversion cost guide.
What's the cost per square metre for an extension?
£1,600-£3,500 /m²
The per-m² method explained, and the published UK rate.
How much does a porch cost?
£4,000-£12,000
Published UK ranges for building a porch, from a basic uPVC canopy to a brick-built entrance.
How much does a side extension cost?
£1,600-£3,500 /m²
Published UK ranges for a side and side-return extension.
How much does a bungalow extension cost?
£2,750 /m²
The published per-m² rate for extending a bungalow, and what a dormer loft addition adds on top.
How much does a kitchen renovation cost?
£6,200-£16,800
Published UK ranges for fitting a new kitchen.
How much does a rear extension cost?
£1,600-£3,500 /m²
Published UK ranges for a single-storey rear extension.
How much does a wraparound extension cost?
£1,600-£3,500 /m²
Published UK total-cost ranges for a wraparound (L-shaped) extension.
How much does a bathroom renovation cost?
£4,500
Published UK ranges for a mid-range refresh versus a full new bathroom.
What's the general building cost per square metre in the UK?
£1,775-£3,000 /m²
The published baseline rate behind most of the cost guides on this site.