Calculating the Cost Of Building a New Home

By June Fletcher
From The Wall Street Journal Online

Question: I want to build a 2,800-square-foot home with four bedrooms, two and one-half baths, a gourmet kitchen, walkout basement with media room and three-car garage in Pennsylvania. How can I estimate the cost to build the house? And what do you think about modular homes?

-- Sheila, Spring City, Pa.

Answer: According to B4UBuild.com, which sells books on the subject of cost estimating, the average cost-per-square-foot to build a home on site is between $95 and $150.

Contractors generally agree that cost-per-square-foot is a terrible way to budget for a home, because there are so many variables involved. Do you insist on top-of-the-line cabinets and appliances for your gourmet kitchen, or will mid-range ones do? Are you planning to side the house with cheap vinyl or expensive stone brick? Is the house going to be one story, or two? (The latter is generally cheaper because the foundation is smaller.) Will you have simple, rectangular rooms that minimize the materials and the labor required for framing, or unusual shapes like octagons with vaulted ceilings? What sort of flooring, bathroom fixtures and heating and cooling system will you have? Is the lot easy to access, relatively flat and easy to dig, or is it rocky, heavily wooded and uneven?

There are a few Web-based calculators that can help you make rough cost calculations. One easy-to-use, free one is Building-Cost.net, which adjusts not only for the quality levels of finishes and fixtures, but also for location, down to the city level. But bear in mind that this and other calculators won't give you an exact estimate, since ultimately that will be determined by the profit margins of the contractor you hire -- information you can't really know in advance.

So if you go the site-built route, I suggest that you start with a dollar amount that you're willing to spend. Interview at least three contractors and check their licenses and references and look at their work.

Once you've found someone you like and trust, the two of you can take your preliminary budget and work backwards, including the must-haves and eliminating the mere wish-I-hads as money allows.

Be sure to keep a cushion of at least 10% to 20% of the total project cost to cover last-minute changes, delays and other problems you can't foresee (for example, the cost of lumber spiking mid-project).

Now to your question about modular homes. Manufacturers of these homes, which are built in a factory in sections, say they are a lot more durable than site-built ones, since they are constructed in controlled conditions. But modular homes still make up only a tiny fraction of new home sales -- only 3.6% of the 1.06 million new homes sold last year, according to the National Modular Housing Council. (Click here for a list of manufacturers.)

That's partly because some consumers remember how uninspired modular homes looked in the 1980s and because some people still confuse them with so-called "manufactured homes," also known as mobile homes or trailers.

But these days, computer-aided design means that almost any house plan you choose can be made into a modular home. I think modular homes are fine and definitely worth considering, as long as you can visit a model or a nearby factory. Don't assume you'll save a few bucks, however. In fact, by the time the house is delivered to your lot and assembled, it may cost as much as a site-built one.