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Structural calculations for a multi-storey steel frame with horizontal T-connections, carried out for the owners’ association on the Wattlaan

For the owners’ association on the Wattlaan, we carried out the structural calculations for an extensive steel frame spread over several storeys. The project centred on a precise structural analysis, with particular attention to the stability of the steelwork and the correct transfer of loads to the foundations. The steel frame consists of several storeys […]

Further causes of collapse under heavy snow loads

In the January 2026 issue of the Dutch journal De Ingenieur, Rob Nijsse, emeritus professor of structural design, identifies snow load as a major factor in the collapse of roofs and other structures. He also mentions other possible causes, such as local snow drifts and the extra load from building services and solar panels. What is striking, however, is what this analysis […]

Removing a column creates a large open space. A section with a widened bottom flange was used for this. See the four photos below.

A finite element program helps you find the causes of cracks.

Assessing chimneys

New lifts in existing town houses

The lift walls perpendicular to the strip foundations are heavily loaded. And this while the strip foundations are already very heavily loaded on paper because of the increased (design) values for variable loads. Without extra measures, the strip foundations are then often overloaded. A practical and economical measure is to spread the load parallel to the strip […]

Strengthening a bathroom floor on Bethlehemweg in Utrecht

During the bathroom renovation, the contractor noticed excessive deflection of the timber joists and asked De VerbouwingsConstructeur for advice. We found: Undersized timber joists: 70×150 mm over a span of 4,500 mm, with varying centres of up to 600 mm. In the […]

Thermal resistance calculation

Thermal resistance of 60×160 timber rafters at 660 mm centres. Build-up: rafters with insulation between them, plasterboard below and roof boarding above λtimber = 0.17 W/[mK] Rtimber = 0.16 m/0.17 {W/[mK]} = […]

Pallandtdreef Culemborg

  Here the architect had not required the structural depth to be limited to the original floor thickness. This made spans of about 7.5 m possible with a cambered HEB240 beam, forming part of a new T-piece under the existing rear and side walls. In the front […]

Wall openings in Maarssen

At the start of this project, the client wanted a clear span of more than 7 m to the new rear wall and, perpendicular to it, another opening through to the kitchen. We were able to convince the client that such a large opening would be expensive and difficult: The spanning beam becomes very deep The supporting columns also […]

Raising a floor

Because the large basement was very low and the ground floor very high, we raised a timber floor on Monseigneur van de Weteringstraat in Utrecht. We paid extra attention to resisting possible horizontal forces, installing temporary horizontal propping before an arched structure was […]