All notices in connection with this Lease, the Premises or the Property shall be in writing and shall be personally delivered, or delivered by courier service (e.g., Federal Express, Airborne) or sent by certified mail, return receipt requested, postage prepaid. Notices to Landlord shall be delivered to the address specified in Par. 1(a). Notices to Tenant shall be delivered to the address specified in Par. 1(b) until Tenant takes possession of the Premises; thereafter notices to Tenant shall be delivered to the Premises. All notices shall be effective upon delivery or attempted delivery in accordance with this provision. Either party may change its notice address upon written notice to the other party given in accordance with this provision.