The purpose of GSSBR is to provide REALTOR® members with access to tools necessary to deliver real estate services in an ethical and proficient manner. Our Location: Londonderry Square - 50 Nashua Road, Suite 105, Londonderry, NH. Park in the lot facing Route 102 & enter through the clock tower courtyard. PROFILE OF HOMEBUYERS AND SELLERS: NH OVERSAMPLE Granite State South Board of REALTORS® Londonderry Square 50 Nashua Road, Suite 105, Londonderry, NH 03053 T: (603) 965-3329 F: (603) 893-5655 membership@gssbr.org