Type 3 Asbestos
Termed a Destructive Survey, it is normally required before demolition or major refurbishment and constitutes a thorough survey of all materials within the building and accesses all areas deep into the fabric of the structure.
Using invasive techniques, this uncovers not only the obvious ACM's, but also the majority of the hidden ACM's as well.
The objective here is to find any asbestos and either remove it or make it safe in another way so that demolition or refurbishment operatives can work safely.
The other survey is a management survey and there is more info on this here.