Asbestos testing usually forms part of a survey which could lead to the removal and disposal of materials found to contain a hazard. The reason for testing rather than just removing the materials is that asbestos is dangerous and therefore can be expensive to handle and rid of, so if you get a test result showing no asbestos you may be able to dispose of the materials more cheaply without any risk to health.
There are a lot of buildings in Brighton and Hastings, and indeed across the rest of Sussex that contain asbestos material in one for or another due to the popularity of its use over the three decades or so from the early 1950s.
If you have asbestos in your home, the testing will show this up, and your contractors in Sussex will be able to advise on the safe removal and disposal of the materials along with an estimate of cost.