Construction drawings in Kensington and Chelsea

The Basements SPD and below-ground alterations

The council's local plan is the Local Plan 2024 (New Local Plan Review), adopted in 2,024, and its working document for subterranean work is the Basements SPD. The borough is well known for its approach to basements, and that reputation is built on rules about size, depth, construction impact and drainage.

Large basement excavation is a specialist field and not part of what this site offers. Smaller below-ground work in an existing house, such as lowering a floor in a lower-ground room, forming a lightwell door or adding a rear opening in a retaining wall, still needs a clear technical set. We show the structural support, the waterproofing approach and the drainage levels, so that building control and the party-wall surveyor can assess them without guessing.

Where a project begins to look like a basement in the council's sense, we say so early and explain what further consultants are needed.

Contractors in this part of London are used to working around protected trees, narrow streets and sensitive neighbours, but the drawings should still help. We include a short construction-sequence note on any job that involves temporary props, deliveries through a mews or work near a boundary wall, so the builder sets out the job in a safe order.

Flats, values and the question of who owns what

Just 17 per cent of households live in a house or bungalow, and owner-occupation is 31.7 per cent. Many alterations therefore involve a lease, a managing agent and a neighbour above or below.

With values that high, tolerances are tight and so is the specification. We name finishes, glazing, ironmongery and insulation products, where the design depends on them, and give the performance each must reach. The stair, escape window, smoke alarm and ventilation figures in the table apply whatever the building is worth.

The borough charges its own levy under the Borough CIL Charging Schedule, plus Mayoral CIL at £80 per square metre. Our floor areas follow the levy's convention.

We would rather say early that a project is more than the standard set can cover. Complex subterranean work, a structural frame replacement or a listed building with unusual fabric may need extra consultants, and we explain who and why at the quote stage so that the budget is realistic from the start.

Decisions and timing in the Royal Borough

The council decided 664 householder applications in its latest year and granted 93.7 per cent, with 91.9 per cent decided within eight weeks or an agreed extension. Those are borough-wide figures, and a listed building or a protected garden is a different test.

The council also issued only 25 lawful development certificates in the data period. With so many Article 4 directions and so many flats, which have no householder permitted development rights, planning permission is usually the route.

Because the planning stage is the slow one, we start technical coordination alongside it and issue construction drawings close to the decision. A builder with a complete set can price, order long-lead joinery and mobilise promptly.

A narrow permitted route makes the quality of the first submission matter even more. A technical set that follows the approved drawings closely avoids the amendment applications that otherwise add months.

Where to go next in Kensington and Chelsea

The borough overview is at architectural drawings in Kensington and Chelsea, and the approval stage is at building regulations drawings in Kensington and Chelsea. For beams and foundations see our structural calculations.

Neighbouring boroughs include Westminster, Hammersmith and Fulham and Brent. The service is described generally at construction drawings in London.