The Party Wall Solicitor, Matthew Hearsum, recently brought attention to the Building Owners future liability to RICS Building Surveying Journal December 2013 / January 2014. Often taken as a given, it is an important point to raise in engagements with Party Wall Surveyors and clients.
Building Owners or those persons (for the sake of discussion BO1) carrying out work in pursuance of the Party Wall etc. Act 1996 must bear in mind that they may be personally liable for the cost of additional works to adjoining owner’s property required as a result of the adjoining owner, now a Building Owner (BO2), undertaking works in pursuance of the Party Wall etc. Act 1996.
This stems from S7(2) of the Party Wall etc. Act 1996 which states:
“The building owner shall compensate any adjoining owner and any adjoining occupier for any loss or damage which may result to any of them by reason of any work executed in pursuance of this Act.”
Similarly, the result of which may also precipitate in S7(1) as a cause to inconvenience.
Any loss to an adjoining owner must be quantified in an accurate valuation. Such losses can include perceived loss in value to property as a result of the works. The costs must be paid by the BO1 2 months after the day of completion of work by the Adjoining Owner S11(10).
This contrasts to the provision in S11(9) of the Party Wall etc. Act 1996 which makes the adjoining owner liable for costs incurred at the time of construction should they make design requests in respect of making a structure compliant with their future use. It is supportive of S11(10) in the context of special foundations (reinforced concrete).
The liability is said to be “personal” and cannot be annexed to the property register and therefore passed to the successors in title. As a result of carrying out works under the Party Wall etc. Act 1996 a Building Owner may therefore encounter a claim for loss years after the property has been sold. Mason v Fulham Corpn  1 KB 631 & Carlish v Salt  1 Ch 335, relate to earlier legislation but place significance on the disclosure of the served Awards and Notices under the Party Wall etc. Act 1996 to purchasers.
That said such cases were heard before the Law of Property Act 1925, later Land Registration Acts, Land Drainage Act 1991 and better defined principles of benefit and burden in freehold estate, concepts your legal adviser should be able to assist with.