Drawing accuracy

Hello,

I am currently planning to renovate my house (1966).

I have looked at the old blueprints and had them digitized, and now I am comparing the "as is" and "to be" in order to plan properly.

I have measured and compared various dimensions, and at the same time I am incorporating my change requests.

Now my question is, with what accuracy does one have to work here?

The drawings deviate by up to 5-20 cm in some cases, but on the other hand I cannot measure everything to ± 1 mm either... where is the reasonable middle ground?

Best regards and thanks

The basis of any renovation planning is always a construction survey and the creation of current as-built plans in 2D/3D. A mere digitization does not necessarily reflect the actual condition. In some cases, deviations from the original planning have already occurred during the shell construction phase – this becomes evident at the latest during demolition/renovation when the shell structure is not as specified by the structural engineer or if, over the decades, more or less significant changes have been made to the building.

To avoid surprises during implementation, the building survey and condition analysis (construction damage, quality of the building fabric, usability of the shell and finishing construction) should be carried out very carefully and professionally. This saves the most costs.

With a construction survey at accuracy level II (handheld laser device), deviations from the actual condition – depending on the deformation of the building – of up to 10 cm on the exterior dimensions of the building are tolerable, to be expected, and unavoidable.

Thank you for the quick and expert response 1+