Most of the living space in a friend's rental apartment in a 10-unit brownstone is located under the terrace of the apartment directly above his.
The new tenant in that apartment regularly does some kind of physical workout on the terrace that results in major pounding noise coming through into my friend's apartment. The new tenant insists he can make whatever noise he wants up until 11:00pm. (He apparently is also related to the landlord.)
What recourse does my friend have?
Are there any special laws that apply to a tenant's use of their terrace -- e.g., as an outdoor gym?
If relevant, my friend's apartment is rent-stabilized but the other apts. in the building are now all unregulated.
Thanks.