Biodiversity net gain plans in Kensington and Chelsea

Protected trees in a small, heavily planted borough

There are 4,560 tree preservation orders and 41 preservation zones, a very large count for a borough where only 17.5 per cent of land is domestic garden. Every mature plane, lime or fruit tree in a communal garden square therefore carries real weight in the metric.

Large trees score highly in the statutory metric, so losing one adds heavily to the habitat a scheme must replace. We plot each tree by size and condition class before any layout is drawn.

The borough also holds 16 registered parks and gardens, so planting proposed for the gain should read as part of the historic setting, not against it.

If a protected tree stands on a neighbouring plot but its root zone reaches your site, it still counts in the constraints picture. We read the root protection area onto the drawing, because it fixes where hard surfacing, a lightwell or a new cellar wall can safely go.

Which projects here are exempt

Only 17 per cent of households live in a house; most work is to flats and mews properties, and most of it is a householder or listed-building style alteration that is exempt. Permitted development and householder extensions need no plan, though the form must record why.

Sites at or below 0.2 hectares are exempt unless priority habitat is present, and impacts below 25 square metres of habitat are de minimis. In practice, a mews plot is likely to qualify unless it holds a veteran tree or other priority habitat.

When a project does need a plan, it is usually a replacement house or a new dwelling in a garden, where a basement is also proposed.

A replacement house is treated as a new dwelling, so the old building does not buy an exemption. Habitat lost under its garden, however small, is measured. For a pure refurbishment of the existing house, we confirm in writing that no plan is needed and keep that note on the file.

How the plan and the drawings fit together

We draw the baseline parcels, the proposed planting and the trees to be retained on one landscape sheet, so the arboricultural report, the metric and the planning drawings quote the same site. Our planning drawings carry that sheet, and a new build set adds the roof planting layer.

Minor applications are granted 93.2 per cent of the time across 840 decisions, so a coherent file matters more than speed. The gain must then be maintained for at least 30 years.

Our independent check applies to this document as it does to every drawing: a second chartered technologist, not the person who drew the sheet, reads the metric against the landscape layout before it leaves us.

Price and next step

There is no list price, as the work follows the number of parcels and trees. You receive a fixed quote after a free constraints check.

Send the address, with any tree survey you already hold. We will tell you whether the condition applies, and what to avoid touching until the baseline is recorded.