external construction supervision - on-site appointments

Hello,
we have just received an offer for external construction supervision.
The basis for this offer was our construction documents and the construction and service description of the BU.
A total of 7 on-site appointments are assumed. However, 5 of these alone are before the completion of the roof structure. Then again after the screed and one for the final acceptance.

Now I just wanted to ask, where are the critical points where someone external should definitely take a look?

Thank you
Hilaria

An external technical construction supervision with 7 on-site appointments can of course only check the particularly critical construction stages. It is correct that several crucial construction stages have already taken place by the phase described as the creation of the roof truss. It is important to inspect especially the so-called hidden services, i.e., the points that later cannot be checked or can only be checked with great effort (e.g., slope of the drain pipes, waterproofing of basement/floor slab/insulation in drywall partitions, etc.).

A reliable external construction supervision, in my experience, is only possible with at least an average of 2 site visits per construction activity week – of course, additional site visits by the builders themselves. Here, a good briefing of the builders by the construction supervisor can save some on-site appointments of the construction supervisor. "Häuslebauer40" has already created a good checklist. It is a matter of safety (and of course costs for the external construction supervision) how thoroughly the inspection should be conducted.

To illustrate this with the example of screed: it already begins with checking the tolerances of the ceiling before installing the floor structure; as a rule, pipes are laid within the floor insulation level, and it must be checked whether the cavities are filled; if underfloor heating is installed, the pipes must be filled and pressure tested; the insulation, especially at the edges, must ensure that no contact occurs between screed and wall (sound bridge), etc. These aspects are no longer visible after the screed installation.

I recommend demanding technical inspections (not partial acceptances) at the respective times before important works are concealed. That means only after your confirmation or the confirmation of the construction supervisor you have commissioned may certain work proceed, e.g., before installing the screed. It is also advisable to request delivery notes for materials and measurement protocols.