AAC Blocks vs Red Bricks: Cost, Strength and Practical Differences
A practical comparison of AAC blocks and burnt clay bricks for Indian homes — cost per wall area, weight, strength, insulation, workmanship needs and where each is the better choice.
For an RCC-framed home the walls are infill, and the choice between autoclaved aerated concrete (AAC) blocks and burnt clay bricks is about weight, speed, insulation, cost and — importantly — the workmanship each demands. Neither is universally better.
Side by side
| Burnt clay brick | AAC block | |
|---|---|---|
| Typical size | 230 × 110 × 75 mm | 600 × 200 × 100/150/200 mm |
| Dry density | 1,700 – 1,900 kg/m³ | 550 – 700 kg/m³ |
| Compressive strength | 3.5 – 10 N/mm² (varies widely by kiln) | 3 – 4.5 N/mm² (consistent) |
| Thermal conductivity | ≈ 0.8 W/mK | ≈ 0.16 – 0.24 W/mK |
| Water absorption | 15 – 20% | 10 – 15% but slow to dry |
| Mortar | Cement mortar 10–12 mm joints | Thin-bed adhesive 3–4 mm, or cement mortar |
| Speed | Slower (more units, thicker joints) | Faster (fewer units) |
| Indicative wall cost (2026, Pune, material + labour) | ₹95 – ₹125 per sq.ft of 230 mm wall | ₹85 – ₹115 per sq.ft of 200 mm wall |
Where AAC wins
- Lower dead load — around a third of brick — which can reduce beam and footing sizes on framed structures.
- Better insulation, noticeable in west-facing bedrooms in summer.
- Faster masonry and less mortar.
- Consistent quality from a factory rather than a kiln.
Where brick wins
- Load-bearing construction — AAC blocks are not used for it.
- Better fixing for heavy wall-mounted items without special anchors.
- Parapets, plinth walls and other exposed masonry where AAC needs careful waterproofing.
- Sites where masons have never worked with AAC — bad AAC work cracks more than average brick work.
Getting AAC right
AAC cracks when it is laid wet, when walls run long without control joints, or when RCC–masonry junctions are not meshed. Blocks should be laid dry with thin-bed adhesive, lintels provided over openings, mesh fixed at every junction with columns and beams, and plaster (or a suitable putty system) applied after the wall has settled. On the projects we execute, AAC in the superstructure with brick at parapets and plinth is the usual combination.
Frequently asked questions
Do AAC blocks make the house cooler?
Noticeably, for external walls with sun exposure — thermal conductivity is roughly a quarter of clay brick. It does not replace roof insulation or shading; the terrace slab is usually the larger heat source.
Can I hang a TV or a geyser on an AAC wall?
Yes, with AAC-specific anchors (chemical or long-thread fixings) rather than ordinary plastic wall plugs. Plan heavy fixings and use the right anchor.
Which is cheaper overall?
Per square foot of wall they are close in Pune in 2026; AAC often wins on total cost once lower dead load, faster masonry and less mortar are counted, provided the masons know the material.
Prices are indicative and vary with location, design, specifications, market conditions and project scope. They are not a quotation.