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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

PropertyFacing BrickDense BlockAircrete Block
Standard size215 x 102.5 x 65mm440 x 215 x 100mm440 x 215 x 100mm
Units per m²601010
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 speed400-500 bricks/day100-150 blocks/day100-150 blocks/day
Area covered/day7-8 m²10-15 m²10-15 m²
Compressive strength20-100 N/mm²7.3-22 N/mm²2.9-7.3 N/mm²
Lambda value (W/mK)0.771.13-1.630.11-0.15
Weight per m²~120 kg~200 kg~55-70 kg
Weather resistanceExcellent (facing grade)Needs render/claddingNeeds 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 TypeMaterials/m²Labour/m²Total/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.

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Last updated: April 2026

Verified against UK standards · estimates only, confirm with your supplier.