Structural calculations in Kensington and Chelsea

Two soils in one borough

An Arup hydrological review, as reproduced by a basement contractor, describes the borough in two halves. The entry reads North London Clay; south River Terrace Gravels over London Clay.

For a beam that matters at the foundation. Clay in the north can swell and shrink with moisture, while gravels over clay in the south drain differently. Our calculation notes the soil assumption beside each new bearing, so the engineer or the examiner can see why a padstone or a pad foundation was chosen.

Trees add to the picture. The council records 4,560 tree preservation orders, plus 41 protected zones, and a street tree's roots are a real input to any foundation near a boundary.

Listed houses, conservation areas and Article 4

The borough has 39 conservation areas, 84 Article 4 directions and 1,350 listed entries, plus 16 registered parks and gardens.

On a listed house, structural work is as much a heritage question as an engineering one. The calculation records which historic walls and floors are altered and what replaces them, which the council's conservation team needs alongside our planning drawings in Kensington and Chelsea.

A tall terraced house has party walls on both sides and several floors that may load a single wall. We survey every level that bears on an opening, not only the floor you are standing on.

A borough of flats and tall houses

Only 17 per cent of households live in a house, and 31.7 per cent own their home, so many structural jobs here are inside leasehold flats. A lease commonly needs the freeholder's licence before any wall comes out. Our calculation set is written so that it can be sent to a managing agent as it stands.

How the borough decides householder applications

The council decided 664 householder applications in its latest published year, granted 93.7 per cent and decided 91.9 per cent in time. The in-time share is the figure to build into your programme.

Tall terraces and the loads that gather in them

A tall terrace can rise through several storeys over a lower ground floor, with a chimney stack and party walls at each side. A rear opening at ground level may carry a closet wing, a floor of bedrooms and part of the roof, and each of those loads travels down through the same piece of masonry.

We therefore survey upwards, not only at the opening. We note wall thickness at each level, the direction the joists span, whether the rear wing has been altered before and whether any earlier steel was fitted. That history decides how much capacity is left in the old brickwork.

With the facts in hand the engineer can size the new beam and, where the masonry is tired, specify a spreader or a deeper padstone. The result is a calculation your builder can follow and a managing agent can read without needing us on the phone.

Our fee and delivery

We fix our Kensington and Chelsea fee from £295 with VAT included, after checking the address and the work. You receive the calculations, a beam and padstone schedule and a layout drawing about a week after the survey, reviewed by a second technologist.

The same figures feed our building regulations drawings in Kensington and Chelsea, so the examiner meets one consistent set.

More for Kensington and Chelsea

See architectural drawings in Kensington and Chelsea for planning constraints in the borough, loft conversion drawings in Kensington and Chelsea for roofs, and the national structural calculations guide for the rules behind the numbers.