Recommended position for wall vents ?

A relation is upgrading their 40 year old bungalow.
Got a company who specialise is concrete coring to core and provide wall vents in 5 rooms.
Vents were provided at top of the window in 3 of the rooms.
There are steps to the front door and the floor level of the front rooms is 1.0m over the ground level outside.
Rather than provide the vents at the same height as the other rooms, I guess that the contractor drilled from outside and the vents are only 0.3m off the floor.

I have a look at Part F and found
"1.2.2.4
Typical types and locations of
background ventilators are illustrated in
Diagram 5. Background ventilators should be
located, as far as possible, so as to avoid
draughts, e.g. more than 1.75 m above floor
level"

Contractor was paid on the day work was done.
Is there any approach that I can make to the contractor to reposition the vents at a higher level ?