As moderator of the estimating forum at jlconline.com, I'm
often asked if cost books are a reliable way to get cost
figures to use for estimating. There are many cost books
available, updated yearly, by RS Means, Craftsman, BNI,
Saylor's, HomeTech, and others. They obviously serve some
purpose, or they wouldn't be published year after year. The
question is, what's the right way to use them?
Where the Numbers Come From
The introductions of these books often contain a little blurb
along the lines of "We contact dealers, manufacturers,
distributors, and contractors around the country to compile
national average costs for the items listed." Because the costs
are national averages, there's usually a table in the back of
the book that provides multipliers for most major cities. The
multiplier allows you to adjust the dollar amounts in the book
to fit the cost of building in your area.
Each book includes a list of items like material cost, labor
productivity in hours, labor cost in dollars, equipment cost,
and profit and overhead. Material cost is typically shown
together with the unit of measure for the item. Sometimes it's
difficult to determine exactly which materials the price
includes, especially with "assemblies," groups of items that
show up as a single entry in the book. For example, does the
cost of a prehung door take into account nails, casings, and
shims? What's included in an assembly such as an 8-inch masonry
wall? Some price books explain the assumptions; others leave it
up to you to determine the details.
Cost books are updated yearly, and material prices are based
on costs at the time of publication. That's okay for some
items, but what happens when prices change between updates?
Plywood and OSB went through the roof in 2003, but the 2003
books were published in late 2002.
The author sometimes uses a cost book
(such as Craftsman'sNational
Repair & Remodeling
Estimator, shown here) to bid a
task for which he has no historical job-cost data. He modifies
the published numbers by comparing them with numbers for a
similar task for which he knows his cost. If you use numbers
directly from a cost book, don't forget to apply the area
Labor rates. As with
material costs, you need to understand what is and isn't
included in the labor rates in the book. Most books include a
"productivity factor" — how much time it takes Joe to
install one unit of a given item. They also contain a "craft
code," which indicates who will be doing the work —
carpenter, mason, or whoever. The final component is the "labor
rate," the cost per hour for the trade that performs the task.
Craft codes and labor rates are usually summarized in a table.
It's important to review not only the labor rate for each trade
but also the burdens that are applied to them. Some books don't
apply any labor burden; it's assumed to be in the overhead and
Overhead and profit. Every
cost book publisher seems to handle overhead and profit
differently. Some don't list it at all, assuming you'll add it
in at the bottom of the estimate. Others put it in a column
next to the labor, material, and other costs. Usually, it's a
straight percentage multiplier with an explanation of what it
Proceed With Caution
Given their limitations, you have to use cost books carefully.
If you take a number straight from the book, don't forget to
use the multiplier for your area. And you should always verify
that the material pricing in the book is correct. Compare the
listed labor rates and labor burden multipliers to your known
costs; both figures can vary wildly from your own payroll
costs, even after you've applied the location multiplier.
Finally, verify that the listed markup percentages are correct
for your company.
So what's the point of using a price book if you have to
verify all the costs that are in it? For me, there are two. The
first is to find a productivity factor for an unknown task. The
second is to price a subcontracted item that it's hard to get a
bid on or that I've never priced before.
Like most estimators, I look at my own job-cost data to see
how long it takes to do things. If I don't have data for a
particular task, I'll look up its productivity factor in the
cost book. Then I'll check the book by looking at its rate for
an item that I do have data on.
For example, say I want to estimate running crown but have no
historical cost data on it. However, I have a lot of historical
cost data for baseboard, so I can check the crown rate by
looking up the rate for base. The cost book says that a
carpenter can install 100 linear feet of base per hour, while
my data shows that my carpenters run 80 feet an hour, or 80% of
the rate in the book. So if the book says a carpenter can
install 16 linear feet of crown per hour, I'll assume that my
crew can do it at 80% of the listed rate, or 12.8 linear feet
If I can't get a price from a subcontractor for an item I need
to estimate, I'll find a similar item in that trade that I have
sub pricing on, and compare the book cost for that item to what
I've had to pay for it. Again, I apply the percentage variance
to the listed cost for the unknown item. Whenever possible,
I'll also list that item as an allowance, with the
qualification that hard costs for the item couldn't be
determined before presenting the estimate. If that's not
possible, I'll add some contingency to the number, to cover any
possible variance that may occur from using this method.
Recommended for Remodelers
Which cost book you use is mainly a matter of personal
preference. My advice is to head to the library or bookstore
and thumb through as many as you can. Find one that has data on
the tasks you regularly estimate. Look up the cost data for
categories where you know your own costs; choose a book with
costs that are as close as possible to your own.
Of all the cost books, I prefer Craftsman Book Company's
National Renovation and Insurance Repair Estimator or
its National Repair and Remodeling Estimator. Both
books seem to have the best breakdown of items used in
remodeling (though they are organized slightly differently and
use different rates for the various trades, for some reason).
If you consider these books, take a look at both and choose the
one that has an item breakdown and labor rates that are close
to the ones you use.
Bob Kovacshas over 15 years of experience managing
and estimating residential and commercial construction
projects. He can be reached by e-mail at