If your remodeling project includes any structural changes, it will be necessary to consult a structural engineer who will provide you with the required stamped drawings that must be submitted, along with the architectural drawings, to the building department for approval.
Remodels and additions are types of projects where you have an existing structure (your home for example). A remodel takes an existing area (like a kitchen or bathroom) and changes it. An addition is slightly different because it adds space to the existing area (like a sunroom addition). New construction is any type of project that develops an area that currently has no existing construction. New homes and detached garages are good examples of new construction.
-- Tips courtesy of HomeAdvisor.com