If you work in a professional service industry you've likely been asked the question "why is your service necessary?" It is a question that I encounter regularly, though not many folks are frank enough to say it outright. So, I'll ask it. Why is hiring a designer or architect necessary for remodels, additions, and new builds?
Have you ever noticed that the people at the gym that work out with a personal trainer look to be in a lot better shape than those who are training themselves? There are obviously exceptions to that, but the physical trainer has a knowledge about the human body that allows he or she to make suggestions and recommendations that will target certain areas that need work. They have that expertise as a result of training and experience. Architecture and building design is similar. Designers and architects have training and experience that gives them insight into space organization, material selection, structural efficiencies, fund distribution, etc., that can make the difference between a suitable (or possibly, unsuitable) space and wonderful space.
The job of the architect is to utilize his or her experience and knowledge about construction and design to take the budget and desires of the client and produce a result that satisfies the clients desires while at the same time satisfying code requirements and structural and system efficiencies (mechanical, plumbing, electrical) and produce a space that is pleasing and enjoyable to occupy (enjoyability = beauty + durability + usability).
Here are a few questions that you should discuss with your architect as you begin the design and planning phase of your project:
Do my desires jive with my budget? (Talk with your architect and contractor about this. Being up front about your budget is necessary to avoid project overages and confrontation later!)
What is most important item on my list of desires? (EVERYTHING may not be possible, so think it through!)
What do I want the space to FEEL like? (character is important and it is affected by the form and arrangement of the space, not just by furnishings!)
What is my timeline? Is it realistic? (Being done tomorrow is likely not possible. Rarely is a project as simple as you may think, so having this conversation right away with your architect and contractor is imperative!)
Find and hire a good architect for your project. It will be worth every penny.