If your domain name is changing and you want to preserve rankings, you will want to review Googles Change of Address Tool Procedures (this will ensure that Google knows what your domain is changing to and will require you to forward your old domain name to the new one).

Alternatively we can manage this process for you for an additional $200 in labor cost - just mention this to your lead designer at some point during development or before your development site is moved to the live domain and we can provide further instructions.