How many bricks do I need for a garden wall?

For a half-brick (single skin) wall, you need approximately 60 bricks per square metre. For a full-brick (one brick thick) wall, you need approximately 120 bricks per m². These figures include 10mm mortar joints and are based on standard UK bricks (215mm x 102.5mm x 65mm). Add extra bricks for piers — 4 bricks per course per pier.

How high can I build a garden wall without planning permission?

Under UK permitted development rights, you can build a garden wall up to 1 metre high if it fronts a highway, or up to 2 metres elsewhere without planning permission. However, structural limitations apply: a half-brick freestanding wall should not exceed 450mm without piers (BS 5628). Always check with your local planning authority.

Do I need foundations for a garden wall?

Yes, all freestanding garden walls need a concrete strip foundation. For walls up to 1 metre high, the minimum foundation is 450mm wide and 225mm deep. For higher walls, increase the foundation proportionally. The foundation should be at least twice the width of the wall and be built on firm, undisturbed ground below the topsoil.

How often should piers be spaced on a garden wall?

Piers should be spaced at maximum 3 metre centres along a garden wall, plus one at each end. For half-brick walls, piers are essential for any wall over 450mm high. Piers are built by bonding an extra half-brick width into the wall at regular intervals, creating a thicker, stronger section that resists wind loading.

What mortar mix should I use for a garden wall?

Use a 1:6 cement to sand mortar mix (one part cement to six parts building sand) for garden walls in sheltered positions. For exposed positions or below damp-proof course level, use a stronger 1:4 mix. Add plasticiser to improve workability. Use sharp sand for foundations and building sand for bricklaying mortar.

Do I need coping stones on a garden wall?

Yes, coping stones are strongly recommended on top of a garden wall. They shed rainwater away from the wall, preventing water from soaking into the brickwork and causing frost damage. Common coping options include twice-weathered concrete coping, bullnose brick-on-edge, and natural stone coping. Coping should overhang the wall by at least 25mm on each side.

Garden Wall Calculator — Bricks, Mortar & Foundations

Calculate bricks, mortar, pier bricks, coping stones and foundation concrete for freestanding garden walls. Complies with BS 5628.

Wall Length

Total length of the wall

Wall Height

Height in courses (1 course = 75mm)

Wall Type

60 bricks per m²

Pier Spacing

Max 3m centres per BS 5628

Include piers

Essential for half-brick walls over 450mm high

Include coping stones

Weather protection on top of the wall

Include foundation

450mm wide x 225mm deep concrete strip

Price Per Brick (optional)

Enter your brick price for a cost estimate

How We Calculate This

Our garden wall calculator works out the total number of bricks needed for the wall face, piers, mortar quantities, coping stones and foundation concrete.

The formulas

Wall bricks = Wall area (m²) × Bricks per m²

Pier bricks = Number of piers × 4 bricks/course × Courses

Courses = Wall height ÷ 0.075m (65mm brick + 10mm joint)

Foundation volume = Length × 0.45m wide × 0.225m deep

Brick quantities per m²

Half brick wall (102.5mm): 60 bricks per m²
Full brick wall (215mm): 120 bricks per m²

Key standards (BS 5628)

Half-brick freestanding wall: Max 450mm high without piers
Pier spacing: Maximum 3m centres
Foundation: 450mm wide × 225mm deep minimum for walls up to 1m
Mortar mix: 1:6 (cement:sand) for sheltered positions

All calculations comply with BS 5628 and general best practice for freestanding garden walls in the UK. For retaining walls, structural engineering advice is required.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.