Structural calculations in Kingston upon Thames

Trees, clay and foundations in Kingston

Trees weigh heavily here: 7,145 tree preservation zones are recorded. A protected tree beside a rear extension can fix where a foundation may go, and where roots exist the calculation records the depth and spread the engineer has assumed.

The borough also has 17 per cent Green Belt. In that land the size of the original house sets a limit on an extension, so the structure is designed for a building whose size has already been settled with the planners, not one that may shrink.

Suburban houses, extensions and the beams behind them

Of Kingston's households, 61.5 per cent live in a house, and 60.9 per cent own their home. Owners of houses are the ones who knock through, extend and convert lofts.

A frequent calculation is a rear opening in a house that already has a ground floor extension, where the new beam may bear on an old wall of unknown build. We survey the existing wall, say what it is, and let the engineer decide whether it can take the point load or needs a pad.

Where scaffolding, props and temporary works matter, the council's own wording for larger structural schemes is useful. It asks for an outline method showing Outline CMS with temporary-works sequence. Our calculation notes include a temporary support sequence in the same spirit, even on a small job.

Conservation areas and listed buildings

Kingston has 28 conservation areas, 114 Article 4 direction areas and 163 listed entries. In those streets the look of the roof and walls can matter as much as the structure, so we keep our planning drawings in Kingston upon Thames and the calculations drawn from one survey.

Householder applications in Kingston

The council decided 742 householder applications in its latest published year. It granted 83 per cent and decided 92.5 per cent in time. Settle the design before you order steel, because the structure follows the permitted form.

Regularising work already done

A buyer's surveyor may find a steel beam with no paperwork behind it. The council's higher regularisation charge reflects the extra work of assessing a structure after the fact, and the engineer's own task is harder because the steel is covered.

If that is your position, we start with a survey of what is visible, then ask the builder or previous owner for anything they hold: a delivery note, a photograph of the beam before it was boxed in, a sticker on the web. The engineer checks the section against the loads and says whether it passes, or what must be added.

Doing the calculation before the work costs less and avoids opening up. If you are weighing a quick job against a proper one, remember that a calculation in the file also helps when you sell.

Cost, contents and checking

Our fixed fee starts at £295 including VAT for a typical Kingston house, confirmed after we know the work. The package has the calculations, a schedule for the steel supplier and a layout sheet, usually ready a week after survey, with a second technologist's check before issue.

Changes asked for by the council are revised without a further charge, and the figures carry into our building regulations drawings in Kingston upon Thames.

Nearby and national

The neighbouring borough of Merton has its own fee lines and soil notes. For the Kingston overview read architectural drawings in Kingston upon Thames, and for the rules behind the beam sizes see the structural calculations guide.