Legitimate and tax compliant building contractors (and their clients) should be delighted that Revenue in that area are active in combatting the black economy in a visible way.
My sister is having work done on her house at the moment (Dublin 14 area). Scaffolding up all around the house. Officials from the Health and Safety Authority have called twice in the past 3 weeks to check the scaffolding passes and also to ensure that the men on the scaffolds are wearing helmets..
The Health and Safety Authority will be calling to more and more 'private' projects after June - see my thread on this below.
It is also possible that you may get a call from the Local Authoritys Building Control Officer who will inspect for compliance of the building with building regulations. The chances of this are small, however, given their known inspection rates.