Garden Wall Calculator
Bricks, blocks, or stone - single or double skin - with mortar, coping, piers, DPC, and foundation concrete across multiple wall sections.
60 units per m² (for stretcher bond, single skin) - adjust unit size above if using a different manufacturer.
5% for simple runs, 10% for standard, 15%+ for complex cuts/piers.
One coping unit per 300-450 mm of wall length.
Polythene DPC roll, 2 courses above ground. Calculated in linear metres.
Typically 3x wall width. Min 300 mm for single skin.
Min 200 mm for low garden walls; 300 mm where frost risk or soft ground.
Structural piers - typically every 1.8-3 m on single-skin walls over 600 mm high.
Adds drainage aggregate, weep holes, drainage pipe, and geotextile membrane calculations.
Wall Sections
Job Costing (optional)
Pro featurePopulate cost fields with current UK market prices. Sign in or upgrade to access.
Results
Face area
-
m²
Bricks to order
-
inc. waste
Cement bags (25 kg)
-
bags
Sand
-
tonnes
Material List
Section Breakdown
| Section | Length | Height | Face area (m²) | Bricks | Piers |
|---|
🚫 Estimate waste & skip size for this project →
Doing this as a homeowner?
Who do you actually need to hire for this?
Not sure what some of these terms mean?
Browse all →
Frequently Asked Questions
How many bricks do I need for a garden wall?
With 10 mm mortar joints: half-brick single-skin wall = 60 bricks/m²; full-brick double-skin = 120 bricks/m². A 10 m x 1.2 m single-skin wall: 10 x 1.2 x 60 = 720 bricks before waste. Add 5-10% waste for cuts and breakages.
What foundation does a garden wall need?
All freestanding garden walls need a concrete strip foundation. Minimum depth: 450 mm below ground level (deeper on clay or in frost-prone areas). Width: 3x wall thickness. A half-brick wall (102 mm) needs a 300 mm wide x 150 mm deep C20 concrete strip. Allow 48 hours to cure before bricklaying.
How high can I build a garden wall without planning permission?
In England, permitted development allows: up to 1 m adjacent to a highway; up to 2 m elsewhere - no planning permission needed. Conservation Areas, AONBs, and listed buildings: permitted development rights may not apply - check with your Local Planning Authority before building.
How much mortar do I need for a garden wall?
Approximately 1 bag (25 kg) per 50-70 bricks. Standard mix: 1:5 cement:sand for garden walls; 1:3 or 1:4 for below-ground or exposed conditions. Pre-mixed bags are convenient for small jobs. For larger walls use a mixer: approximately 1 bag cement per 4-5 bags builders sand with plasticiser.
Do I need coping stones on a garden wall?
Strongly recommended - copings protect the wall top from rain and frost damage, which is the most common cause of garden wall failure. Coping must overhang the wall face by 40-50 mm on each side. Options: concrete or stone saddleback copings, engineering brick on edge, or natural stone. Bed in 1:3 mortar with a weathered flush joint.
How do I build a stable retaining wall in a garden?
Up to 600 mm high: single-brick (215 mm) wall with good concrete foundation. 600 mm to 1.2 m: double-leaf construction with piers at 2-3 m centres. Always include weep holes at the base (every 1-1.5 m) or a land drain behind to prevent water pressure build-up. Over 1.2 m retaining soil: consult a structural engineer.