How much does a beam and block floor cost per m²?
Updated 6 October 2026 · prices for 2026
Typical cost of a beam and block floor
£6,130–£11,230
for 20 to 40 m², dug out, insulated and screeded, including VAT (£5,110–£9,360 + VAT)
About £234 to £255 a m² before VAT. Dig out 300 mm, hardcore, DPM, precast beams and infill blocks, 120 mm PIR, vapour control layer, screed, and the spoil taken away in skips.
A beam and block ground floor costs about £280 to £305 a m² including VAT (£234 to £255 before VAT) in 2026. That's a typical extension floor, dug out, insulated and screeded, with the spoil taken away. For a 30 m² floor that's about £8,940 including VAT (£7,449 before VAT). Smaller floors cost more per m², because the digger, the low loader and the skips cost much the same either way.
What's in the price
We priced a 30 m² floor with 4 m beam spans. This is where the money goes, before VAT.
- Digging out: 300 mm taken out by a mini digger, about 15 hours, with two days' self-drive hire and the low loader there and back.
- Skips: the 9 m³ of soil bulks up by about a third once it's dug, so it fills three 8-yard skips, about £1,150. That's the single biggest line after the materials.
- Hardcore and DPM: about 7 bulk bags of MOT Type 1 under the void, compacted, and a 1200-gauge membrane.
- Beams and blocks: 59 m of 155 mm precast beams and 285 lightweight 3.6N infill blocks, grouted. About 17 hours to lay.
- Insulation and VCL: 120 mm PIR boards over the beams, then a vapour control layer.
- Screed: sharp sand, cement and fibres, about 10 hours to lay.
All in, it's about 65 hours of labour. Materials make up about half of the price, labour a quarter, and the skips and plant the rest.
Price per m² by size
| Floor | Before VAT | With VAT | A m² |
|---|---|---|---|
| 20 m² | £5,106 | £6,127 | £255 |
| 30 m² | £7,449 | £8,938 | £248 |
| 40 m² | £9,359 | £11,231 | £234 |
If you quote these as a builder, notice how the fixed costs behave. On a 20 m² floor, the two days of digger and the low loader are spread over fewer metres. Quoting a flat rate per m² from a big job will leave you short on a small one. Priced on its own, a job like this carries a small premium for travel, setting up, a minimum charge and part-used materials. Done as an extra while you're already on site, the same work usually costs a bit less.
Beam and block or a concrete slab?
On price there's little in it. A 30 m² ground-bearing slab with the same insulation priced at £7,449 before VAT in Bricken, the same as the beam and block floor to within a pound. Beam and block earns its place where the ground is poor, where trees or drains make a slab risky, or where the engineer wants a suspended floor with a ventilated void. The structural engineer and building control decide. The price follows.
How we priced it
We built the floor in Bricken, the quoting app for UK builders, item by item. Merchant prices for the materials, typical hourly rates for each trade (£22 an hour for a groundworker, before markup), and a typical builder's markup of 30% on materials and plant and 35% on labour. The beam price is Bricken's own estimate, so check it against your supplier's quote, which will come with the beam layout. Your builder will price it at their own rates, so get a few quotes.
Builders can open the same calculator, change the area, span and dig depth, and see the price move line by line.
Priced in Bricken at standard UK rates (20 m² for the low figure, 40 m² for the high). Each figure is then multiplied by Bricken's regional factor, from 0.90 in the North East to 1.30 in inner London. The factors come from public 2025-26 build-cost guides and our own quotes. Where a region covers two areas, the low uses the lower factor and the high the higher. The factors are set for whole building jobs, so treat small differences as a guide.
Cost by region
| Region | 20 m² floor | 40 m² floor |
|---|---|---|
| London | £7,350£6,127 | £14,600£12,167 |
| South East | £6,860£5,719 | £12,580£10,482 |
| East of England | £6,430£5,361 | £11,790£9,827 |
| Midlands | £5,940£4,953 | £11,230£9,359 |
| North West | £5,820£4,851 | £10,670£8,891 |
| North East and Yorkshire | £5,520£4,596 | £10,670£8,891 |
| South West | £6,430£5,361 | £11,790£9,827 |
| Wales | £5,640£4,698 | £10,330£8,610 |
| Scotland | £6,130£5,106 | £11,230£9,359 |
What pushes the price up or down
Up
- Soft or wet ground: the beams may need deeper bearings, sleeper walls or oversite concrete. A 30 m² floor with oversite and 6 m of sleeper wall priced at £8,649 before VAT, about £1,200 more.
- Longer spans: past about 6 m the beam supplier's tables need checking, and deeper beams cost more.
- Thicker insulation: 150 mm PIR instead of 120 mm, to meet a tighter U-value.
- No room for a skip: a grab lorry or barrowing the spoil through the house adds time.
- London: labour, skips and parking all cost more.
Down
- Leaving the screed out: if a floating floor or UFH screed goes on later. The same 30 m² floor without screed came to £6,418, about £214 a m².
- Spoil kept on site: the three skips on a 30 m² floor are about £1,150 of the price.
- Bigger floors: the digger, low loader and skips are partly fixed, so the price per m² falls as the floor grows.
- Shallower dig: if the levels allow less than 300 mm to come out.
Questions
Is beam and block cheaper than a concrete slab?
At extension sizes they come out about the same. In Bricken, a 30 m² ground-bearing slab with the same 120 mm insulation came to £7,449 before VAT, the same as beam and block to within a pound. The choice usually comes from the ground, the trees nearby and the engineer, not the price.
How long does it take to lay a beam and block floor?
Our 30 m² example has about 65 hours of work in it, so roughly a week for two people from dig to screed. The screed then needs drying time before floor finishes go down.
Do I need building control for a beam and block floor?
On an extension, yes, the floor is part of the building regulations application. The beam layout normally comes from the supplier's drawing, and building control may want to see it. Check with your local building control before you start.
What's included in the price per m²?
Dig out and cart away, hardcore, DPM, beams, infill blocks and grout, 120 mm PIR, a vapour control layer, the screed, and the labour and plant for all of it. Floor finishes, underfloor heating and professional fees are not included.
Is VAT included?
The big figures include VAT at 20%. If your builder isn't VAT-registered, the price before VAT is closer to what you'll pay.
Related guides
How we price: each figure is a Bricken quote built from the sizes, at standard UK merchant prices and day rates, with a typical builder’s markup. Your builder’s price will differ: get quotes.