I bought my property in January 2005. I am the second occupier of the property. The house was built around 2002/2003 and has a 10-year NHBC Buildmark policy which expires in July 2013.

I have recently discovered that vermin are occupying the wall cavities and loft spaces. There is no doubt about this as I caught one in the main loft. I have been round the house to ascertain possible entry points such as soffits, barge boards, signs of burrowing, etc. Nothing obvious can be found.

I’m concluding, after a bit of research, that entry must be from under the ground (as I can’t find anything above the ground), perhaps from gaps left during the building stage.

My next action, which I have not yet taken, was to ask an expert such as Rentokil for their opinion. If they conclude that vermin are gaining access to the house from a defect in the building, do I have a legitimate complaint against my NHBC policy from which I can claim?