Brick vs Block Walls — UK Construction Guide
Comparing brick and block construction for UK buildings — speed, cost, thermal performance, structural capacity and when to use each.
Side-by-Side Comparison
| Property | Facing Brick | Dense Block | Aircrete Block |
|---|---|---|---|
| Standard size | 215 x 102.5 x 65mm | 440 x 215 x 100mm | 440 x 215 x 100mm |
| Units per m² | 60 | 10 | 10 |
| Cost per unit | £0.40-1.50 | £1.00-1.50 | £2.00-3.50 |
| Material cost per m² | £24-90 | £10-15 | £20-35 |
| Laying speed | 400-500 bricks/day | 100-150 blocks/day | 100-150 blocks/day |
| Area covered/day | 7-8 m² | 10-15 m² | 10-15 m² |
| Compressive strength | 20-100 N/mm² | 7.3-22 N/mm² | 2.9-7.3 N/mm² |
| Lambda value (W/mK) | 0.77 | 1.13-1.63 | 0.11-0.15 |
| Weight per m² | ~120 kg | ~200 kg | ~55-70 kg |
| Weather resistance | Excellent (facing grade) | Needs render/cladding | Needs render/cladding |
Pros and Cons
Facing Bricks
Pros
- + Attractive finish — no rendering needed
- + Excellent weather resistance
- + High compressive strength
- + Wide range of colours and textures
- + Very long lifespan (100+ years)
Cons
- - Slower to lay (60 units per m²)
- - Higher material cost
- - Poor thermal insulation on its own
- - Higher labour cost per m²
- - Heavier — needs adequate foundations
Concrete/Aircrete Blocks
Pros
- + Faster to lay (10 per m²)
- + Lower material cost
- + Aircrete gives excellent insulation
- + Lighter weight (aircrete)
- + Easy to cut and chase
Cons
- - Needs render/cladding externally
- - Lower compressive strength (aircrete)
- - Less attractive unfinished
- - Aircrete blocks are fragile during handling
- - Dense blocks have poor insulation
UK Cost Comparison (2026 Prices)
Cost per m² of finished wall (materials + labour):
| Wall Type | Materials/m² | Labour/m² | Total/m² |
|---|---|---|---|
| Facing brick (half-brick wall) | £30-95 | £35-50 | £65-145 |
| Dense concrete block (100mm) | £12-18 | £20-30 | £32-48 |
| Aircrete block (100mm) | £22-38 | £20-30 | £42-68 |
| Full cavity wall (brick + aircrete) | £60-130 | £55-80 | £115-210 |
When to Choose Each
Choose Bricks When
- External face is visible and appearance matters
- Matching existing brickwork on extensions
- High structural loads (retaining walls)
- Conservation areas requiring brick finish
- Garden walls and boundary walls
Choose Blocks When
- Internal leaf of cavity walls
- Walls to be rendered or clad
- Speed and lower cost are priorities
- Thermal performance is important (aircrete)
- Internal partition walls
Building Regulations
Under Part L 2021, external walls in new builds must achieve a U-value of 0.26 W/m²K or better. A standard cavity wall with brick outer leaf, 100mm full-fill cavity insulation, and 100mm aircrete inner leaf typically achieves 0.22-0.28 W/m²K depending on insulation type. Structural design should comply with BS EN 1996 (Eurocode 6) for masonry.
Related Calculators
- Brick Calculator — calculate bricks, mortar and sand for any wall
- Block Calculator — calculate blocks and mortar for walls
How We Calculate This
Frequently Asked Questions
Related Calculators
Composite vs Timber Decking
Compare composite and timber decking: cost, maintenance, durability and environmental impact for UK gardens.
Render vs Plaster
External render vs internal plaster: materials, drying times, costs and when to use each.
Copper vs Plastic Pipe
Copper vs push-fit plastic plumbing pipe: cost, longevity, freeze resistance and ease of installation.
Tile vs Slate Roof
Concrete interlocking tiles vs natural slate roofing: weight, cost, lifespan and aesthetics.
Last updated: April 2026
All calculations are estimates. Verify with your supplier.