There may be a few reasons why there is excess material being thrown away including wrong take-off amounts being ordered and even over-supply of materials by the supplier… it happens!! Not often but in my experience on commercial projects it does. (steel rods – used to fix steel in slab & footings mainly on corner edges of slab(stop blow-outs),steps in slab, footing cages & starter bars for blockwork – should be engineered, checked and approved by the Builders Engineer . Do you have Strucural Slab plans?). Other reasons for material being wasted/thrown away is as DWolfe suggested is % of allowable waste… but anything above 10% extra means the Builder is wasting his margin!

As for the paper in walls where bricks should be and bricks laid vertically, I smell owner-builder work there….however if it is a new build from a "professional"builder I would be interested to know the name of the builder so we can all keep clear!!

The building process should not be stressful  …… If variations are kept to a minimum eg.design signed off with colours, carpets, tiles, fixtures etc to try and eliminate (haha) this the builder/foreman should be the only one stressing on problems that will raise their head in the project.

Best of luck with the rest of your build, hopefully if you ask your builder why the waste he can give you the answer. As for the independant certifier/inspector being engaged, I assume it should be able to be done as it is on commercial projects so that the construction works by the builder/contractor meets the industry standards.

Hope that helps.

Cheers!