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CROSS Safety Report

Alterations to existing buildings with no site visits

Report ID: 365 Published: 1 January 2014 Region: CROSS-UK

This report is over 2 years old

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A reporter is concerned about structural engineers developing structural calculations and drawings based on the Architects’ drawings only, with no site visits.

Key Learning Outcomes

For construction professionals and clients:

  • There is always a risk that safety will be compromised when the lowest cost is the main criteria for selecting products, processes or people

  • The condition of a building should be properly checked and investigated prior to works starting

  • Structural calculations and assessments should be carried out by a suitably qualified engineer for all structural works 

For civil and structural design engineers:

  • If possible attend site to carry out a walkover and inspection prior to commencing the design

Full Report

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The Full Report below has been submitted to CROSS and describes the reporter’s experience. The text has been edited for clarity and to ensure anonymity and confidentiality by removing any identifiable details. If you would like to know more about our secure reporting process or submit a report yourself, please visit the reporting to CROSS-UK page.


A reporter is involved with structural alterations and extensions to existing domestic buildings and smaller commercial type buildings. Structural engineers are doing the structural calculations and drawings based on the Architects’ drawings only, with no site visits. This leads to some questions:

  • If the Architects drawings do not show any floor, wall or roof construction or even floor spans, roof spans etc. how is this being done?

  • How can you alter a three storey building when you may not even have the first or second floor plans?

  • How do you even know if the architect’s drawings are correct (many first floor wall positions are slightly off centre relative to the ground floor walls etc.)?

  • How can a project receive building regulation approval if the engineer has never even seen the property?

The reporter blames fee competition and the potential reduction in fees to the client if site visits are avoided.

Expert Panel Comments

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Expert Panels comment on the reports we receive. They use their experience to help you understand what can be learned from the reports. If you would like to know more, please visit the CROSS-UK Expert Panels page.

It is of course wrong for engineers, or anyone involved in refurbishment, not to properly check or investigate the actual condition of a building before work starts. Those involved are leaving themselves open to serious action should there be a problem.

Even if drawings exist, they need to be treated with caution. Alterations are made over the years which may not be recorded, and deterioration may have occurred. Making alterations without proper information or verification is potentially dangerous.

Reckless fee competition to the degree where sound engineering and construction is compromised may lead to consequences that affect public safety.

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