Rough idea of home addition cost

[Mosey]

I’m planning to build a 14 foot x 26 foot addition (364 square feet), which will be 2 bedrooms. It’s a pretty simple addition, extending the length of my ranch house another 14 feet. There is no basement, just crawl space. I’m planning to do it myself, if I can find the time, but was wondering what it would cost to have it built. Is there a rule of thumb I can use to get a rough idea of what a contractor would charge that would include everything including wiring and extending the ductwork and finishing the inside? What about just framing it in and doing the roof and walls and then I do the wiring and ductwork and finish the inside?

[dourobob]

The best rule of thumb I've ever heard on these types of projects is estimate your materials costs, add to that your estimates for labour costs and multiply the total by your phone number - you might be closer than you really want to be! [img]/w3tcompact/icons/laugh.gif[/img][img]/w3tcompact/icons/laugh.gif[/img][img]/w3tcompact/icons/laugh.gif[/img]

Bob

[Carl_NH]

Mosey,

Pending the interior and exterior finish $75-100 PSF complete or $27-36K. If they do the concrete, rough in the walls, windows and roofing (weathertight) I would suspect about $17-20K ready to finish with you doing the demo of old exterior wall, then flooring, drywall, wiring, trim, doors heat/ac.

You also might consider 16'x26 since the 16' is 4'increments for plywood, sidewalls and roofing materials, plus would give some room for closets, as finished inside space in each room will be roughly 12'x13' without closets at present.

Other considerations - matching roofing and siding - depending the age of both you may want to redo the entire roof while at this, also siding if brick or vynil getting an exact match is tough.

Carl

[mdbarb]

You could check out the book: RS MEANS residential cost data
It gives labor and material prices for complete houses, remodels and just portions ie electrical, plumbing etc. It is also adjusted for different areas of the country. Lots of information here. Then of course double everything.....
I find building costs around here (San Francisco area) to be inching towards $300 sq. ft.!

[Mosey]

Thanks Carl. So based on that, without having to go through and total up the cost of the materials, how can I come up with a rough estimate of how much the materials will cost of I do it all myself?

[StoneHeartFarm]

About the only thing you can do to figure the rough materials cost is draw up your plans and pull out your calculator. Since building materials very widely in price between different suppliers, and in different regions and even different times of year, you really need to get a list together and let the different lumber yards bid the materials out. Even with a pretty good list, it'll still be rough because things are going to be added in as you go. (The extra outlet that you suddenly decide you need, etc).

SHF

[Carl_NH]

Mosey,

Rule of thumb materials are half the cost. So in your case probably $16-20K

I find it best labor cost wise to start construction late fall (Sept/Oct) with the plan to have it weather tight by late Nov, so when the industry slows you can shop the interior work during the winter months when it's usually more reasonable.

Here's what I would guesstimate your material costs to be:

Site Prep & Concrete $2000
Sidewalls, Subfloor & Roof Framing $6,000.
4-6 Windows and 2 Doors $1500.
Siding & Roofing New section $2500
Insulation $1000
Wiring $500
Sheetrock/Drywall / Paint $1000
Flooring & Fixtures $1500.

As mentioned in the previous post, the best way is to start a spreadsheet, (or on a piece of paper) list everything you can think of then print and take to a few lumber yards and have them price this out.

Carl