Expert: Richard Taylor, AIA - 2/3/2009

Question
Hi, I have traditional centerhall colonial with side entry 2 car garage.  I have a mudroom that is the same level as the garage.  Therefore you are at the same level with the garage, but not the main home.  I need to take 2 small steps up to go into the house.  I would like to raise the floor, so that it is level with the rest of the house.  The mudroom is on the slab.  I would also like to add a full bathroom there since we have pool and guest can get ready there and not all the way upstairs.  I would then remove the powderroom in the center of the home, which is a pain since it separates the kitchen and den. So my question is it possible and what do you think it would cost.  The bathroom pipes are on the same side as the mudroom for hookup.

Answer
Hello Mia - thanks for your question!

You can easily raise the floor over the slab area; you'll want to be sure to use pressure-treated wood, and to take other measures to control moisture in this area.

It will also be important to make sure there's room for plumbing lines and any heating/cooling ducts you may want to run under the floor.  Even though the supply lines are close to the laundry, it's the drain lines that you need be concerned about.  The toilet bend and the traps for the shower or tub will be especially critical - best to consult a plumber on this before you commit to the design.

Keep in mind that you'll want to raise doors, trim, etc. - you'll probably end up gutting the mudroom in the process.

You'll also need to make sure you have room in the garage for the two steps you're going to add - they'll protrude at least a foot and a half into the garage space.

The bath you want to remove may be connected via plumbing to a bath upstairs - if that's the case it may complicate removal, since you'll have to keep or relocate any drain lines that connect upstairs baths to the lower level.  Some of the walls of the 1/2 bath might also be bearing walls for the floor above - be careful what you remove!

As far as cost, you'll need to talk to a local contractor to get a useful number - a wild guess from me won't do you any good!  Each situation is different and much depends not only on the existing construction but also on the finishes you choose.  I'm sure that if you describe to a contractor what you'll told me, he'll be able to get you in the ballpark.

Hope this helps!

Richard Taylor, AIA
www.rtastudio.com
www.rtaplans.com