Estimating in Building Construction

48 CHAPTER SIX

Once the activity list has been developed, it can be orga-
nized into a precedence diagram network schedule. A dis-
cussion of this methodology is clearly outside the scope of
this book, and Figure 6.5 is included for reference only.
There are many excellent scheduling books on the market
that cover scheduling in great detail.
Once the project duration has been determined, it needs to
be converted into calendar days. In the example in Figure 6.5, the
project duration is 50 days. For a 5-day workweek, the duration
is 10 weeks or 70 calendar days. If there are nonwork periods in
that intervening 70 days, the calendar duration would be
extended by the number of nonwork periods. Typical nonwork
periods are holidays such as New Year’s Day or Christmas.

6–5 Contingencies

On virtually every construction project, some items are left out
or not foreseen when the estimates are prepared. In some cases,
the items left out could not have been anticipated at the time of
estimating. Should a contingency amount be included? That is,
should a sum of money (or percentage) be added to the bid for
items overlooked or left out? This money would provide a fund
from which the items could be purchased.
If the money is allowed, it is not necessary to be quite so
careful in the preparation of an estimate. But, if an accurate
estimate is not made, an estimator never knows how much
to allow for these forgotten items.

Contingencies are often an excuse for using poor estimat-

ing practices. When estimators use them, they are not truly esti-

mating a project. Instead of adding this amount, the proper

approach is to be as careful as possible in listing all items from

the plans and the project manual. This listing should include

everything the contractor is required to furnish, it should esti-

mate labor costs carefully and accurately, and it should include

the job overhead expense. To these items, add the desired profit.

The most rational use for contingencies is for price escalation.

6–6 Checklist

Undistributed Labor

 Job superintendent

 Assistant superintendent

 Engineers

Job engineers

Field engineers (surveyors)

Expediter

Cost engineer

Scheduling engineer

 Timekeepers

 Material clerks

 Security personnel

 Project meetings

 Submittal coordination

 Secretaries

To Estimate Cost

Labor

Expenses If the company policy is for per diem, the

cost would be the following:

The duration of each staff person on the projectPer diem

If the project location is remote, the cost of relocation

should be included:

Persons to be relocated Cost per person

(get estimated cost from moving company)

If the staff personnel do not relocate but commutes on a regu-

lar basis, a policy on the frequency of trips needs to be estab-

lished and that policy needs to be integrated into the estimate.

Cost of travel for executives for job site visits must be

included.

Temporary Buildings, Enclosures, and Facilities

 Temporary fences

 Temporary sheds

 Storerooms

 Storage and handling

 Temporary enclosures

Number of weeks on the projectWeekly rate

FIGURE 6.4.Activity List.