Most of the Sevenoaks district sits in the Kent Downs National Landscape (AONB), which tightens planning scrutiny on anything visible from the highway — material choices on front patios, boundary walls and driveways are expected to fit local character, often favouring locally-derived stone and muted finishes. Rear-garden patios and outbuildings are usually still Permitted Development within the standard Class E limits (single-storey, under 2.5m eaves within 2m of a boundary, under 50% of total garden area covered), but Article 4 directions on some streets remove those rights. We check the AONB boundary and any Article 4 designation before quoting.

A ground-level patio is generally Permitted Development. Raised decking or terracing over 300mm above ground is never PD regardless of location. Garden rooms (Class E) meeting the standard limits are usually permitted — single-storey, under 2.5m eaves within 2m of a boundary, covering under 50% of the garden, behind the principal elevation — but the AONB and Article 4 directions on several Sevenoaks streets remove those rights, and Sevenoaks District Council tends to favour natural stone and muted finishes for any works visible from the highway. We advise on whether a Certificate of Lawful Development is worth obtaining before works start.

Sevenoaks sits across two distinct geologies. On the Lower Greensand Ridge — Knole Park, Kemsing, Otford and most of the town — the sandy Folkestone and Hythe Beds drain quickly, sub-bases can be shallower, and soakaways work well. In the Gault Clay vale to the north and north-west, conditions mirror Maidstone: seasonal shrink-swell, poor infiltration, and a need for deeper sub-bases, geotextile membranes and piped drainage rather than soakaways. We inspect the ground before quoting because the spec — and cost — on a greensand plot can be meaningfully lighter than on an adjacent clay plot a street away.