Structural calculations in Camden

Basements in Camden need more than a beam

The council is clear that a basement is a different class of structural work. Its requirements list a Basement Impact Assessment for all new or enlarged basements; 5 stages, prepared by suitably qualified professionals, and the council publishes Basements CPG (Camden Planning Guidance) to go with it.

Section 106 agreements for basements commonly cover CMP and basement construction plan via s106, so the construction method becomes a legal commitment, not only a drawing note.

Our structural calculations cover the frame, openings and loads in the house above. They do not replace an impact assessment, which needs ground investigation and specialist input. If a basement is on your list, say so at the start and we will say plainly what we can and cannot cover.

A borough of flats and period conversions

Only 13.3 per cent of Camden's 92,759 households live in a house or bungalow, and just 29.7 per cent own their home. Structural work here is therefore often done inside a flat, in a converted terrace or in a mansion block, where a lease and a freeholder sit between you and the wall you want to open.

A freeholder usually wants to see the calculations before it consents to removing a wall. A building control officer wants the same figures. We write them so that either reader can follow the load path from the beam down to the foundation, and we state the assumptions about floors above so that a neighbour's engineer can check them.

Where a flat sits below another, the temporary support while the beam goes in matters as much as the beam. We note the propping sequence on the layout.

Heritage constraints around the structure

Camden has 40 conservation areas and Historic England lists 1,971 entries here, including 57 at Grade I. Structural work to a listed house is not only an engineering question. Removing a wall can alter a plan form the listing protects, and the report has to be cross-referenced to drawings the conservation officer will read.

In a heritage case we survey more slowly. We record the existing fabric, any previous steel and signs of movement, so that the proposed beam is shown to be a minimal intervention. Photographs, trial holes where the owner agrees to them and a clear description of what is being removed all help the conservation officer see that the structure has been understood before it is altered.

The same survey helps in a practical way. Old floors often hide timber of mixed age and size, and a calculation based on the sizes we measured is far more reliable than one that assumes modern joists. It also tells the builder which parts need care when the steel is lifted into place.

Price and what you receive

Structural calculations start at £295 including VAT, fixed after the constraints check. You receive the calculations, a beam and padstone schedule and a layout drawing, usually about a week after the survey. A second technologist checks the set, and we revise at no charge if the council asks.

If the work also needs an application, our planning drawings in Camden carry the structural intent, and the building regulations drawings in Camden take the calculations into the construction set.

Related pages

For the whole borough, start with architectural drawings in Camden. The service itself is set out on the structural calculations page, and a neighbouring council's approach is shown in Westminster.