I'm pretty ambivalent about employee reviews. From having done them, I know they are time-consuming if you are conscientious. I don't have any experience whatsoever in receiving a review. I know I am not like anyone else (we are all unique after all). Nevertheless I don't get it. If you don't give feedback daily/weekly, how does an annual/semi-annual review make up for it? If you do give feedback daily/weekly, what is an annual/semi-annual review for?
My suggestion is to give constant feedback to the employee. Then once or twice a year have a de-briefing that centers on an employee's self-appraisal. I think it would be good for both parties to have this discussion. There are no wrong answers. Who should meet with the employee? Anyone who he/she “works for”, but just the one or two immediate to him/her. There is nothing magic going on, just a conversation that should help each party see things more clearly.
Add to or subtract from these questions to suit your needs or comfort level. Send the questions out; schedule meetings; discuss.
Another take on reviews from a well-known blogger...
Your Soft Skills Inventory
Another helpful post from Godin on a similar topic - Rules For Working In A Studio
Seth isn't thinking about architects in particular but this seems very applicable.