Expert: Bruce E. Johnson - 4/5/2009

Question
I am considering adding a two story addition to my concrete block home that was built in the late '70s. It will sit on a concrete slab that is 9.5' wide by 19.0' long and be divided into two rooms one over the other.  First, what would have to be done in regard to building permits if myself and a relative that is experienced in building build the structure ourselves? Second, how would the new structure attach to the existing structure? Third, if the rooms were built as bedrooms with no plumbing, what would the approximate cost be? Thanks in advance for your help!

Answer
Hi Danny, most building code enforcement agencies allow you build your own stuff, i.e. be your own contractor, as long as the house is in your name.  This means you can draw up your plans and pull your own permit.  You need to contact your local building department to get their own particular needs list.  Most of them have a hand-out telling you exactly what you need to submit, how many copies, etc.  As far as connecting to the existing structure.  It is not necessary to physically connect the new addition to the old house as long as you have enough footing under the new addition to support the weight properly.  I do it all the time.  You keep the masonry of the new separated from the old by 1/2" to 1".  This is called an expansion joint.  It allows the structures to expand and contract independently from one another.  You pack the gap with backer rod and caulk the joint with urethane caulking inside and out.

Plan on at least 100 dollars a square foot for the first level and the roof structure.  60 dollars a square foot for the second floor.  That is if someone else is doing the work.  Cut that price in half for the project if you do the work yourself.  Of course prices vary in every area so you will need to develop a good plan and then do a take off and then get your materials priced out to get a realistic idea as to real cost.  

One final note.  A lot of building departments nowadays require an engineer to sign off on the structural elements of the project.  So you might need to have your plans sealed by an engineer before submitting them to the building department.I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com