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

Under Permitted Development, you can build a garden wall up to 2 metres high without planning permission, provided it does not adjoin a highway. Walls adjacent to a highway or public footpath must not exceed 1 metre. In conservation areas, additional restrictions may apply.

How much mortar do I need per 1000 bricks?

You need approximately 0.5 cubic metres (500 litres) of mortar per 1,000 standard bricks for a standard 10mm joint. This equates to roughly 10 bags of 25kg cement and 1 tonne of building sand for a 1:5 mix.

Garden Wall Calculator — Bricks & Blocks Needed (UK)

Q: How many bricks do I need for a garden wall?

A single-skin brick wall uses approximately 60 bricks per square metre. A double-skin (one-brick) wall uses about 120 bricks per m². For a wall 5m long and 1m high (single skin), you need approximately 300 bricks plus 5-10% wastage, so order 330 bricks.

Q: Does a garden wall need a foundation?

Yes. Every brick or block wall needs a concrete strip foundation. For walls up to 1m high, the foundation should be at least 150mm deep and three times the width of the wall. For walls over 1m, the foundation should be 225-300mm deep. The foundation must be below the frost line (typically 450mm below ground level in the UK).

Complete Guide to Building a Garden Wall

A well-built brick or block garden wall is one of the most permanent improvements you can make to a property. Unlike fences, a properly constructed wall can last over 100 years with minimal maintenance. This guide covers everything you need to know about building a garden wall in the UK, from planning regulations to materials and construction methods.

Brick Quantities

Standard UK bricks measure 215mm x 102.5mm x 65mm. With a standard 10mm mortar joint, the coverage rates are:

Wall Type	Bricks per m²	Wall Thickness	Best For
Half-brick (stretcher bond)	60	102.5mm	Garden walls up to 600mm, decorative walls
One-brick (English/Flemish bond)	120	215mm	Retaining walls, walls 600mm-2m
Concrete blocks (440x215x100mm)	10	100mm	Budget walls (rendered or faced)
Concrete blocks (440x215x140mm)	10	140mm	Stronger block walls, retaining walls

Mortar Requirements

Use a 1:5 cement-to-sand mix (1 part cement, 5 parts building sand) with plasticiser for garden walls. This gives a flexible, workable mortar suitable for external use. For below-ground foundations, use 1:3 mix for extra strength.

Per 1,000 bricks: ~10 bags cement (25kg) + ~1 tonne building sand
Per 100 blocks: ~3 bags cement (25kg) + ~0.3 tonnes building sand

Foundations

Every garden wall needs a concrete strip foundation. The foundation should be:

At least 3 times the width of the wall (e.g., 300mm wide for a half-brick wall)
At least 150mm deep for walls up to 1m
At least 225mm deep for walls 1-2m
Buried with the top at least 150mm below ground level
On firm subsoil, below the frost line (~450mm in the UK)

Piers (Pilasters)

Half-brick walls over 600mm high need piers (thickened columns) at regular intervals for stability. Piers are typically one-brick square (215x215mm) or one-and-a-half brick (327.5x215mm). Space piers no more than 3m apart, at all ends, and at any change of direction.

UK Regulations

Planning and Building Regulations:

Planning: Walls up to 2m high do not need planning permission (1m if adjacent to a highway)
Building Regs: Free-standing garden walls generally do not require Building Regulations approval
Party Wall Act: If building on or near a boundary, you may need to serve a Party Wall Notice on your neighbour
Conservation areas: Check with your local planning authority — restrictions may apply

Cost Guide (2026)

Material	Price	Notes
Engineering bricks (Class B)	£0.50-£0.80 each	Best for below DPC
Facing bricks (standard)	£0.40-£0.70 each	Above DPC, visible work
Concrete blocks (100mm)	£1.20-£1.80 each	Budget option, needs rendering
Cement (25kg)	£5-£7 per bag	Ordinary Portland Cement
Building sand (bulk bag)	£40-£60	~850kg, approx 0.5m³
Coping stones (600mm)	£3-£8 each	Concrete or reconstituted stone

Frequently Asked Questions

How many bricks do I need for a garden wall?

A single-skin wall uses 60 bricks per m². A double-skin wall uses 120 per m². For a 5m x 1m single-skin wall, you need approximately 330 bricks (300 + 10% wastage).

How high can I build without planning permission?

Up to 2 metres in back and side gardens. Up to 1 metre if adjacent to a highway or public footpath. Conservation areas may have additional restrictions.

How much mortar per 1000 bricks?

Approximately 0.5 m³ of mortar per 1,000 bricks. That is about 10 bags of cement (25kg) and 1 tonne of building sand using a 1:5 mix.

Does a garden wall need a foundation?

Yes. Every wall needs a concrete strip foundation at least 150mm deep and three times the wall width. The foundation should be below the frost line (450mm in the UK).

Garden Wall Calculator — Bricks, Blocks & Mortar