DEAR TIM: My current 1,100 square foot single story three bedroom one bath home is not large enough for my growing family. To get a somewhat larger new home that barely meets our needs costs $100,000 more than what I can sell my existing home. It seems as if I need to stay put and add space here. My lot is small so a second story seems the only way to go. How hard is it to add a second story to a home? What do I need to think about? Maria E., Sacramento, CA

DEAR MARIA: It is not too hard to add a second story to a home. You have quite a bit to think about to put it bluntly. In fact, there are so many things to consider, I almost do not know where to start. Fortunately, you have already done part of the mathematical analysis that has illustrated a point many people overlook. You can almost always buy square footage in an existing or used home for far less than new home square footage. A new home in a great location on a nice lot can be very pricey. Older existing homes in great neighborhoods often can be fantastic bargains when you simply compare them to a new home on a finished living space basis.

Adding square footage to your home by going up instead of out presents many challenges. Photo credit: Tim Carter

If you determine you can add a second story, it is time to talk with two remodeling contractors who have done this type of work. Interview a few and ask them to provide addresses of several homes where they have added a second story. Ask them what they feel the current cost per square foot is to add the necessary room to your home. Be sure to ask what the extra cost might be to add a full bathroom. Remember, these are just guesstimate numbers and you should be prepared to pay as much as 20 percent more as the plans are developed and challenges are addressed.

Using these very rough preliminary numbers, see if you can afford to add the amount of space you need. For example, if you feel you need 800 more square feet of space and the remodelers tell you it is going to cost $145.00 per square foot, plus $8,000.00 more for the full bath, you are looking at a possible cost of $124,000.00 plus the 20 percent contingency. Can you borrow $148,800 comfortably? Visit your local banker or mortgage company and ask them to help you with a quick refinancing analysis.

If you qualify for a new loan, you should now start thinking about the actual project. Here is a partial list of the things I see as issues:

• Will the current exterior walls support the load of the second story?
  
  
• Is the foundation strong enough to carry the new load?
  
  
• How will the plumbing from the new bathroom connect to the existing?
  
  
• How will the new staircase between floors impact the existing floorplan?
  
  
• Is it better to install separate heating and air conditioning for the new space?
  
  
• Do you have to install a new electric service and panel for the added loads?
  
  
• Does the contractor know how to minimize sound transmission between the new and old spaces?
  
  
• Is it wise/affordable to add special storage or possibly attic trusses in the new roof to gain bonus space?