Expert: Dan Griffin - 3/25/2009

Question
Thank you for sharing your expertise!

My son and is wife just purchased their first home; a small rambler in a small souther Idaho town.  They are closing on the purchase in about two
weeks.  Of course now they are thinking of ways to make it bigger! (grin)  It is a simple rectangle built over a 4 foot crawl space, cement
foundation.  Money is tight and they plan to do the work themselves (with family help).  I would love to get your input on what type of project
could best be accomplished on a limited budget, with DIY labor to expand the space.  Here is what they are considering:

1).  Adding a screened porch off the back of the house, with hopes to make it enclosed living space in the future.  (Should one create an actual
below ground footing now?  How do you best tie into the roof?)
2). Extend the house out the back on one side (making it a "L" shape).  
3). Digging out the craw space to create a basement.
4).  Adding a porch to the front of the house to make it more inviting from the street and give them a place to sit in the summer.  (They will
probably do this, plus one of the other projects.)
5).  Putting on a second floor. (How do you know if the first floor and foundation will support a second story?)

Any others ideas?

Thanks!
Kirk

Answer
Kirk, the old rule still applies.  Don't overbuild your location.

1.  If you plan to enclose living space, it wil require a footing and vapor barrier.  If you can work with a level slab now, it will simplify some things later.  A big issue will be HVAC.  If you intend to blend the roof line, a perpendicular ridge will probably work best, a bit like a dormer.  Consider how to deal with doorways as the area evolves .

2. The el addition is very subject to the existing floor plan as to what and where the addition would work.

3.  Creating a basement can work.  Do some research about ground water conditons, waterproofing, etc.  Basements are very cheap square footage on new work, but extremely difficult to add.

4.  The porch sounds great.  You do need to check into easement and set back.  Builders usually already have the house as far forward as possible on the lot.  This one will require contacting the local code/building department.

5.  It would be quite unusual that a footing and single story walls would not be able to carry a second floor, but it does need to be verified.  This will require knowing the soil bearing capacity and the dimensions of the existing footing.  It may require an engineer's stamp for the building department.  Make sure there are not height ordinances.   Look at this one carefully.  
Here are a few things to consider on this one:
-you give up the square footage for stair and landings on both levels
-things have to happen very efficiently as you tear off the existing roof and  frame and close in the new.  Rain takes on a whole new meaning.
-2 story HVAC can be problematic.

Sometimes it is best to make small improvements to what you have with plans to sell and upgrade as your needs change.  The exceptions that you see on this old house, etc are rare views, expensive real estate, exceptional locations, etc.