Answer from our Expert by: Martin Holmes, Builders GB. London
The house price could well be affected by your neighbours Loft Conversion, depending on the surveyors eye for detail.
You should get in touch with your local Planning Department and inform them of this situation.
Party Wall Agreements are there for a reason and have to be followed. You can appoint your own surveyor at your neighbours expense and have the Loft corrected.
Ask the council for further advice.
If you did build a Loft Conversion in the future you will have less room to play with because of the neighbours Conversion.
