It Will Cost How Much?
When considering building a custom home or addition, the most common pitfall I've encountered as a builder is when designers and architects are not in sync with today's construction costs. The single most important suggestion I can make when planning a substantial project is to collaborate with a builder you're confident with while in the planning stages of design.
Time and time again after reviewing blueprints, I have encountered the same scenario: a customer who hoped a project would be within a budgeted amount, only to realize that this was not the case. If I were planning to build my dream home, the first thing I would ask my architect would be, "Are you able to design my project within 'x' amount of dollars?" Bringing your builder to the table after rough planning drafts are in place will not only allow you to check your architect's budget-meeting capabilities, but will also create a checkpoint for you to know what's left in your budget for final detail work.