Garden SurveyorSetting Out & Levels
Draw your area, mark the house wall and any focal feature, then get squaring numbers, balanced cuts, falls and a peg & string level schedule.
Changing this swaps the defaults and wording for slabs, block paving, decking boards or pure squaring checks.
How far the paving runs ALONG the house wall. Approximate — drag the corners on the diagram below to fine-tune the exact shape.
How far the paving projects OUT from the house wall. Approximate — fine-tune on the diagram below.
The full width of the house wall the patio sits against (a typical UK house is ~8 m). If it's wider than the patio length, the diagram shows the wall extending past the patio so you can see the paving doesn't have to run the full length of the house.
Pick the drainage detail along the house wall. A shingle strip is the minimum good-practice detail; dry channel and land drain stop the paving a course short of the wall and recalculate the area.
Choose the paving family so the set-out note matches the slab you are laying.
Pick a stock slab or choose Custom to enter your own face size.
Stretcher / stack lay full slabs; diagonal adds angled edge cuts and waste. Carries through to the patio calculator.
Starting cuts: 365 mm along · 590 mm out.
Add return joins a small shape onto this polygon · Add path + area creates a linked pad · Add isolated area creates a separate editable patio part · tap an area button or shape to edit it.
Drainage strip against the house
Suggested: splash strip at ~150 mm deep. Generous DPC clearance and free-draining ground — a decorative splash strip is enough.
≈ 0.41 m³ gravel · 4.4 m² membrane over 5.00 m of wall.
✓ Paving sits 150 mm below the DPC — meets the 150 mm Part C clearance.
Cross-section — updates live with your settings
Where the water goes
Size a soakaway for this runTypical patio/porcelain joint is 5 mm; widen for sandstone or sand-jointed block. Carries through to the material calculator.
1:80 minimum for smooth paving, 1:60 for textured / tarmac.
3 advanced inputs hidden. Switch to Advanced to fine-tune.
- Unit & pattern
- Porcelain paving — 600 × 600 mm slabs, Stretcher bond
- Area
- 15m²
- Run length
- 5m
- Run width
- 3m
- Squaring check (3-4-5)
- 3–4–5 m (3-4-5)
- Diagonal (equal = square)
- 5.83m
- Full units along length
- 7
- Balanced cut (length ends)
- 365mm
- Full units along width
- 3
- Balanced cut (width ends)
- 585mm
- Fall gradient
- 1:80
- Total fall drop
- 38mm
- Peg & string levels
- Datum (house) 150mm · Peg 1 163mm · Peg 2 175mm · Drain edge 188mm
This app provides general UK guidance and material estimates only. It is not legal, planning, engineering or building-control advice. Always confirm requirements with your local planning authority, building control, utility providers, manufacturers or qualified professionals.