received a DCRA notification form for next-door neighbor's work on party wall, structural addition to party wall, underpinning foundation - how best to respond ?

See this  message from a Bloomingdale household:

The adjoining property to our Bloomingdale row house is going to be renovated and we received a DCRA notification form.  (Here is a sample DCRA notification form .)
                                                           
 Says all scope items are part of the plan (work on party wall, structural addition on party wall, underpinning foundation).  
                  
With all the recent development in Bloomingdale, I assume others have received these for projects next to them and am wondering if others have signed or ignored? What legal implications are there if we don't sign and they cause a problem?  Looking for opinions to help us decide how to respond.