There are three types of survey referred to in MDHS 100.

Type 1: Location and assessment survey
(presumptive survey)
The purpose of this type of asbestos survey is to locate, as far as reasonably practicable, the presence and extent of any suspect ACMs in the building and assess their condition. This survey essentially defers the need to sample and analyse for asbestos (or the absence thereof) until a later time (e.g. prior to demolition or major refurbishment). The duty holder bears potential additional costs of management for some non-asbestos-containing materials. All areas should be accessed and inspected as far as reasonably practicable or must be presumed to contain asbestos. Any materials which can reasonably be expected to contain Asbestos must be presumed to contain asbestos, and where it appears highly likely to contain asbestos, there should be a strong presumption that it does. All materials which are either presumed or strongly presumed to contain asbestos must be assessed for potential fibre release.

Type 2: Standard sampling, identification and assessment survey
(sampling survey)
The purpose and procedures used in this asbestos survey are the same as for Type 1, except that representative samples are collected and analysed for the presence of asbestos. Samples from each type of suspect ACM found are collected and analysed to confirm or refute the surveyor’s judgment. If the material sampled is found to contain asbestos, other similar homogeneous materials used in the same way in the building can be strongly presumed to contain asbestos. Less homogeneous materials will require a greater number of samples. The number should be sufficient for the surveyor to make an assessment of whether asbestos is or is not present. Sampling may take place simultaneously with the surveyor, or as in the case of some larger surveys, can be carried out as a separate exercise, after the Type 1 survey is complete.

Type 3: Full access sampling and identification survey
(pre-demolition/major refurbishment survey)
This type of asbestos survey is used to locate and describe, as far as reasonably practicable, all ACMs in the building and may involve destructive inspection, as necessary, to gain access to all areas. A full sampling programme is undertaken to identify possible ACMs. The survey is designed to be used as a basis for tendering for the removal of ACMs from the building prior to demolition or major refurbishment and estimates of the quantities of ACMs are made.
The survey does not assess the condition, surface treatment or accessibility of the asbestos or provide material risk assessments for potential fibre release.