There are a lot of issues here; taking each point in turn we offer the following suggestions:
1. Building Regulations-all building works require approval, do you know when these conversion works were undertaken, if you can establish this you should be able to approach the local authority and obtain a copy of the original approval certificate.
2. Listed Building Consent- similar to building regulations, if you know the date when these works were undertaken you should be able to approach the planners and obtain a copy of the consent, as these are held in the public archive.
3. In terms of the means of escape your Uncle is correct, but there are many ways to interpret the Building Regulations, New Regulations came into force in 2007 and in order to obtain compliance with means of escape a number of criteria have to be satisfied. As we have no dimensions or layout details of the cottage, we can only outline the basic areas you have to satisfy. This information only applies to two storey houses where the new storey is not more than 50sq m and does not create more than two habitable rooms and the existing ridge is not raised.
