The American Institute of Architects, founded in 1857 with 88,000 current members, has laid out an explanation of the services an Architect can provide for owners. Most people focus on "Design Services" via "Architectural Design Documentation" but there is usually a lot more required. Note that some of these items do not apply to residential construction but it is important to understand that an Architect is a potentially valuable resource and that as you choose one, you should consider which of these functions are important to you. As builders (BW does not employ architects), we can give you a second opinion on the the more technical items we believe you'll need to ensure project coherence and permitting approvals.
Take a look at the matrix below: