Expert: Ted Barnhill (Principal, Design45 LLC) - 11/29/2007

Question
We are thinking about adding a family room to the side of our existing house. A room 14' wide x 22' long with 15' ceilings, since it will be 2 stories tall to match the existing house. Room would be on a 3' craw space. I have sketches of what the addition would look like.  My question is that I know my building inspector would want to see heat loss calculations based on my heating system, along with plans. The contractor I would like to use is not a designer, but does excellent work.  Do I need an home architect for this project? And what would be the cost if I needed one.

Answer
Phil,

You will need a set of permit drawings to obtain your building permit.  The extent of these, and level of detail needed, will  depend on your municipality; check with them.  These can be produced by a drafter, as opposed to a designer, if you are confident in your design and simply need structural information, setbacks, egress, etc. indicated for permitting.  Some contractors do their own drafting in house; most will have someone they have worked with to do this.  The cost to draft (not design) your addition will probably be in the neighborhood of 5 percent of your construction cost, if fairly detailed drawings are required.

However, I am nervous about your description of the space.  15' ceilings may make the room feel small in width, and spatially cold if not mediated by finishes, windows, or other architectural elements.  Why are you choosing to "match the existing house" in height?  For your own reference and peace of mind, I would suggest calling a couple of home designers or architects to hear their approaches and fees.  You may find that their 10 to 12 percent fee for complete design and drafting actually saves money, in reducing unnecessary space, streamlining construction (no mid-construction changes), and increased resale value.

Good luck with your addition.  Feel free to ask more questions on this or other projects.