Loss of value due to mine shafts
This text refers to mine shafts used for the extraction of coal and covered under the Coal Mining Subsidence Act 1991.
The first time the majority of people learn of an abandoned mine shaft is when the Coal Authority search comes back.
The Coal Authority search gives detail of past, present and proposed mine workings. Along with positions of mine shafts and adits. They will also give notice of any past claims for Subsidence under Section 46 of the Coal Mining Subsidence Act 1991. The reports are usually a couple of pages long and include a map showing the position of any mine shafts. From 1991 onwards the 20 metre rule was adopted. This made the zone of influence a 20 metre radius around the mine shaft.
Usually the likelihood of subsidence problems related to old mine shafts is remote, and consequently the location of the mine entry should not significantly alter the valuation of a property.
However the public’s perception of properties located within the zone of influence of a mine shaft is usually negative, and this is also often the case of their Surveyor and Solicitor, upon whose advice the public rely.
From a logically perspective the value of the property should only be marginally affected, however the public’s perception is not always based on logic and it is likely, that one will find that a re-sale of a house within the zone of influence of a mine shaft will prove more difficult than would normally be the case.
When there was no evidence of subsidence problems or instability caused by the shaft, the following are percentage reductions we have encountered over the last thirty years.
Ø Mine entry under a property and no records of it being filled/capped, deduct up to but not usually exceeding 30%.
Ø Mine entry adjacent to a property and no records of it being filled/capped, deduct up to but not usually exceeding 20%.
Ø Mine entry under a property and records of it being properly filled/capped, deduct up to but not usually exceeding 10%.
Ø Mine entry adjacent to a property and records of it being properly filled/capped, deduct up to but not usually exceeding 05%.
Ø These percentages are guidelines, each individual looks at the problem from a different perspective, so there is no guarantee that a future purchaser, surveyor or solicitor will adopt the same approach.
Ø Where there is no record of the shaft being filled/capped, this doesn’t necessarily mean that it hasn’t. No record of the shaft being filled/capped, likely means that the records of the work have been lost over the years.
Ø Over the years we have investigated whether or not a mine shaft was indeed located where it is shown on the Coal Authority search. In some instances we were able to prove that the shaft did not exist in the specified location. Therefore just because the Coal Authority search shows a shaft in a specific location, does not necessarily mean it’s actually there. The shafts that were found not exist in the specified location, had been accurately plotted by the Coal Authority based on the records in their possession. And we can only conclude, that in some instances the old records were simply not that accurate.