Can You Update the Calculations to Match What Was Actually Built?

This question arises when construction has deviated from the structural drawings — whether intentionally (the contractor changed the specification) or inadvertently (a wrong section was ordered). The short answer is: yes, in principle, but it involves real cost, it may not always be possible to confirm the as-built work is acceptable, and it delays your project.

First: Establish What Was Built

Before any calculation update can begin, PorthouseDean needs accurate information about what is actually on site. This typically requires:

– Photographs of the installed steelwork or foundation
– Actual section reference (stamped on the steel, or measured from the web and flange dimensions)
– Bearing dimensions and padstone sizes
– Connection details

If the work has already been covered up and is inaccessible, opening-up works may be required — at the client’s cost — before an assessment can begin.

Option 1: Remove and Replace

The simplest and often cheapest resolution is to remove the incorrect work and replace it with the specified construction. In this case:

– No calculation update is required
– The original calculations remain valid
– Building Control can be satisfied by confirming the correct specification has been installed

If the deviation is caught early before work has progressed, this is almost always the right choice.

Option 2: Calculate the As-Built

If the as-built work cannot be removed or the client wishes to retain it, PorthouseDean can quote to assess whether the as-built structure is adequate. This involves:

– A review of the actually used section, connections, and bearings against the design loads
– In some cases, a site visit to measure and record the existing installation
– New calculations confirming (or not confirming) adequacy
– Revised drawings showing the as-built arrangement
– Additional Building Control submission if the original approval has passed its verification stage

This work attracts an additional fee. It is not a simple exercise and — critically — there is no guarantee that the as-built arrangement will prove to be adequate. If it does not pass, further remedial work will be required anyway, meaning the client has incurred the assessment cost on top of the subsequent rectification cost.

Implications for Building Control

If work has been done without notifying Building Control, or if notified work has deviated significantly from the approved drawings, the BCO may require:

– Formal written explanation of the deviation
– Opening up of any covered work to verify what was installed
– Resubmission or supplementary drawings showing the as-built arrangement before a completion certificate can be issued

Contact us as soon as a deviation is identified — the earlier we know, the more straightforward the resolution tends to be.