If you have a mortgage over your property and you make a claim for power line compensation, your mortgage company will be asked to give their consent to the transaction. This is because your house is their security and they have a legal right to object to you granting rights over it if they feel that doing so would affect the value of the property.
This may sound like a bad thing, but in my opinion, its a good thing. I say that because once a mortgage company has reviewed the paperwork and granted their consent, you can be sure that (in their opinion and the opinion of their valuers and lawyers), there will be no negative affect on the property value or potential sale-ability. If they thought that there would be, they would refuse consent and the transaction could not go ahead; mortgage companies simply do not consent to things that may affect the value of their security. Especially in this post-credit crunch era.
Having dealt with almost every lender in existence today (and even some who have since disappeared!), I have not yet come across one that does not give consent on every claim without issue. Once in a while they may make your solicitor jump through a few hoops to get the consent letter, but they all provide it eventually.
Knowing that all lenders are familiar with these transactions and always consent to them is certainly comforting to me when people ask “how do I know that making a claim won’t affect my property value?” – I have always said that the property value is affected by the presence of the power lines; making a claim or not making a claim won’t change that. Its good to know that mortgage companies agree.