It's really an issue with the Environmental Health Officer from the Council. For this type of work a Section 61 agreement is normally in place which will dictate hours and noise levels, as long as the contractor is compliant with this agreement then they are permitted to carry out those works however, more and more councils are not allowing the use of a Section 61 (despite it being their own procedure) so that they can act if they get complaints. It's a PR thing for the councils which penalises and puts all risk onto the contractor.
The question I would be asking of the EHO is, is there a Section 61 in place which permits the noisy activities at xx:xxhrs and if so, what are the constraints?
Also, if the sweeper is there because of dust generated from the demolition then the contractor is almost certainly in breach of legislation as it has a duty of care to reduce risk (actually eliminate is the first port of call) and protect the public and its own workforce and there are many means by which dust emissions can be controlled.
The Archangel