Expert: Daniel Humphrey - 11/5/2008

Question
we have a mobil home (camp) want to add an addition to the front of it. 14f w x 48f l. it will give us more kitchen, livingroom, and bedroom space. how much will it cost?

Answer
Dear Debbie,

I had a chuckle to myself when you asked me how much it would cost! I get a lot of questions about how to build, but I didn't expect that pointed question.

I'm guessing you want the short answer first: It may not be at all relevant where you live and for the kinds of finishes you like, but in my area, such a space finished out fairly nicely would be about $75K, mainly because you're talking about a possible kitchen, which can be very expensive.

The long answer is that you'll need to decide exactly what you want in there before you can get a good estimate. I'd like to get you started doing a cost estimate. If you have Excel, or a spreadsheet program, it will go a lot more smoothly.

For every item, you have a column for quantity, a column for materials, a column for labor, and a column for subtotal.

The first step is to get an idea of how much it would cost in your area to get a foundation, bare walls, and a roof. In my area, this "shed" would cost about $14K. You could start here, or you could break the shed down into its parts, such as foundation, wall framing, wall sheathing, roof trusses, roofing, and trim.

Added to this shed subtotal, you would enter into the spreadsheet as many items as you can think of, such as windows, doors, siding, roofing, trim, paint, and other exterior details. To each of these, you would put in the price for purchasing them and an estimate of what the labor might be. If you don't know what the labor would be, then estimate about the same as the materials cost. Of course, some expensive materials require the same labor, or sometimes less; but the 50/50 estimate will usually get you in the ballpark. It's important on your spreadsheet to have some guess than to leave something blank.

Then for the interior, add all the items you can think of. It's a lot more fun to initially put in some very nice details. You can substitute more realistic choices later as you begin to work within a budget.

You might get the help of a contractor to come up with an estimate. But I recommend going through it yourself first. It's a big investment, and you should have a handle on what affects costs.

Good Luck,

Daniel