Garden Landscaping by the Numbers: Falls, Depths and Heights

Landscaping quotes can be hard to compare, because two gardens that look similar on paper can need very different groundwork. A handful of numbers explains most of the difference: the fall on a patio, the depth of a sub-base, how quickly the ground drains and how high a fence or deck can go. Knowing them helps you ask better questions and judge whether a quote is complete.

Patio falls and levels

• Fall: at least 1 in 80 away from the house, set with a laser level
• Height: at least 150mm below the damp-proof course
• Sub-base: dug to firm ground, with the depth set by what is found rather than a fixed figure

Over a patio 4m deep, a 1 in 80 fall means the far edge sits 50mm lower than the edge by the house. Installers of new patios in Solihull plan the drainage before ordering paving, so the water has a channel drain, soakaway or border to run to.

Drainage: measure before you dig

A timed percolation test in a trial hole shows how fast water drains away. Comparing the result with the area of lawn or paving that drains to it shows whether a soakaway will cope or whether the water needs to be routed elsewhere. On heavy clay the answer is often land drains or a herringbone system rather than a soakaway alone. Reputable providers of drainage solutions for waterlogged gardens test first, then quote one price that includes spoil removal and reinstating the lawn.

Fence, deck and paving limits

• Fences: generally up to 2m without planning permission, reduced to 1m beside a road used by vehicles
• Decking: generally permitted up to 300mm above ground
• Front gardens: non-permeable paving over 5m² usually needs planning permission

Listed buildings and conservation areas can have stricter rules, so check before you build.

Four figures worth charting

1. Area by use: how many square metres go to dining, lawn, planting and paths
2. Hard versus soft landscaping: a simple pie chart shows the balance of paving and planting
3. Cost by element: groundworks, paving, walls, planting and spoil removal as shares of the total
4. Programme: weeks for each stage, from survey to planting

A design-and-build firm offering garden design in Solihull will resolve these figures on a 2D plan and in 3D views before any work starts, then give one fixed price covering labour, machinery, materials and spoil removal, which makes quotes far easier to compare like for like.

The right numbers turn a garden plan into a reliable build. For more on landscaping companies and the metrics behind them, see our landscapers category.