Architectural photographers' rates vary based on many considerations, among which are their cost of doing business, their market (which could be local, regional, national or international), their level of experience and expertise, the production costs to shoot a particular project, their ability to negotiate and the photo usage terms their clients require. To try to find your level, the best you can usually do is try to find out what those whom you consider your closest competitors charge.
I typically charge a creative fee that takes my day rate into account but is not expressed to my client as a specific time-based rate. The creative fee will vary with the nature of the assignment and whether the creative fee accounts for the usage license. I may factor the photo usage/licensing into this creative fee or break it out as a separate fee. To this I will add the production costs specific to the assignment. Typical photo usage for architects and interior designers typically includes collateral and publicity usage, as well as submissions for design contests and editorial publication. However, actual usage of the photos by a design competition should only apply if your client wins, and the usage should only be to promote the award itself unless you are charging an additional fee for broader usage; and the photographer should typically be paid for editorial publication, for which the base commission fee may or may not account. Paid placement (advertising) is usually an additional charge that is negotiated separately. The usage may or may not be time and territory limited, depending upon what the client needs and is willing to pay for. Typically, third party usage and transfer of the usage license are not permitted without additional compensation for the photographer and require the photographer's written permission.