When a homeowner is considering putting an addition onto his or her home, I am frequently asked whether it is better to do a ground floor addition or add a second story. The first determining factor, of course, is whether there is room to expand on the same level. What are the required setbacks in your neighborhood? Are you willing to give up the space in your yard? Generally, if you have the space, then a ground floor addition is the simplest and most economical solution. On the other hand, if you’re constrained by setbacks or don’t want to give up the yard space, then a second story should be explored.Homeowners often wonder if it is less expensive to build “up” because of a potential savings on foundation costs. Well, yes and no. It depends on the bearing capacity of the foundation. Building over the existing house can require foundation work and/or support posts being added to existing walls. Some of this additional work and expense can be avoided by building over the garage, since the garage is typically built on a slab and can bear a second story. An additional consideration is placement of the stairs. When the addition is put over the garage, space can be taken from the garage for the stairs, thereby limiting the disruption to the existing home’s floor plan. In general, second story additions tend to affect more of the existing home than ground floor additions, increasing the scope of the project and consequently the cost. If you’re going to go “up” try to put as much of the addition as possible over the garage. But if space allows, going “out” is probably your simplest solution. Each situation is unique; a design/build company can help you assess what would be best in your individual circumstances.