Structural calculations in Waltham Forest

London Clay and Claygate Beds in Waltham Forest

The council's Contaminated Land Strategy describes the geology as London Clay; Claygate Beds in the north. Clay moves with the seasons, and the north of the borough has a different layer at the surface from the south, so foundation conditions are checked street by street.

In practice we check how deep existing foundations go, whether trees stand close, and what the survey shows about cracking, before the engineer assumes a bearing capacity. That is cheaper than finding a problem once the trench is open.

Basements and heritage buildings

A basement needs a Basement Impact Assessment on every application that builds, extends or deepens one, covering groundwater, neighbours' structural stability, construction method and monitoring. The council's checklist item reads: Chartered engineer or geologist self-certification.

A structural survey is a separate document, and the council limits it: Heritage assets only. It applies to substantial or full demolition, or work affecting structural integrity, in a listed building, a conservation area building or another identified heritage asset.

Waltham Forest has 15 conservation areas and 15 Article 4 directions, and 118 listed entries. We check your address before suggesting a route.

The jobs we calculate in Waltham Forest houses

Typical calculations here belong to a handful of familiar jobs: a chimney breast removed to open up two rooms, a rear wall opened for glazed doors, a loft floor strengthened for habitable use. Each needs the load above the opening traced down to a bearing that can take it.

We survey first, recording wall construction, floor direction and the position of any stack above. The engineer's figures then start from measured facts, and the layout drawing shows every beam, padstone and prop, so the builder installs what was calculated and the officer reads the same sizes.

Trees and Article 4 land in the borough

The borough has published 231 tree preservation orders. A protected tree close to a new wall changes the foundation design, so we record trees on the survey and pass the distances to the engineer. The same survey notes whether a house falls within one of the 807 Article 4 direction areas the council has mapped.

How Waltham Forest decides householder applications

Waltham Forest decided 771 householder applications in its latest published year, granted 81.5 per cent, and decided 90.7 per cent in time. Calculations go to building control, not planning, but the figures help you plan the programme. Where permission is needed, our planning drawings in Waltham Forest take that route.

Price and what you receive

Structural calculations start at £295 including VAT, fixed in advance. The package is the calculations, a beam and padstone schedule and a layout drawing after the survey and checked by a second technologist.

The set feeds our building regulations drawings in Waltham Forest; for engineering beyond calculations see structural engineering in Waltham Forest. The wider service is at structural calculations, the borough overview is architectural drawings in Waltham Forest, and nearby boroughs include Redbridge and Hackney.