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17–1 Electrical Work
Under single contracts, the electrical work is the responsi-
bility of a single prime contractor. In most cases, this
means that electrical contractors will submit prices on the
work to be completed to the prime contractor. The general
contractor will include an electrical contractor price plus
overhead and profit in the bid price on the project. In this
case, the prime contractor is directly responsible for the
work to the owner and must coordinate all of the parties
involved in the project.
With separate contracts, the electrical contractor will
bid the electrical work directly to the owner; the owner will
select the contractor and sign a contract. In this case, the
electrical contractors are responsible for the electrical work;
and although there will be certain mutual responsibilities
and coordination between electrical contractors and general
contractors, according to the general conditions, Article 6,
the general contractor’s responsibilities are not as great as
they would be under single contracts.
All electrical work must be installed in accordance with
the code regulations of a given area. Throughout the United
States, the National Electric Code (NEC) is used extensively.
State and local regulations must also be considered. Before
beginning the takeoff, the contractor should review the plans
and carefully read the specifications. Often the specifications
will require that “all work and installations be in confor-
mance with all applicable national, state, and local codes.”
This statement means that contractors are responsible for
compliance with the laws; if they are responsible for them,
then they better be familiar with them. The codes contain
information regarding wiring design and protection, wiring
methods and materials, equipment, special occupancies, and
other information.
Field experience in construction will be helpful in
understanding the problems involved in electrical work and
how the electrical aspect should be integrated into the rest
of the construction. Without field experience, an under-
standing of the fundamentals of electrical work, and an
ability to read and understand the drawings and specifica-
tions, it will be difficult to do a meaningful takeoff on these
items.17–2 Single Contracts
Because an electrical subcontractor will undoubtedly do the
electrical work, that contractor will do the bidding. Learning
to estimate electrical work is a special skill requiring exten-
sive knowledge of the properties and behavior of electricity.
The complexity of this topic would fill a book by itself. What
is presented here are some issues that contractors face when
dealing with electrical subcontractors. However, by using
some common sense and complete files from past jobs, it is
possible to obtain approximate estimates for checking
whether the bids submitted are reasonable. With experience
and complete files, it is possible to figure an estimate close to
the low bid.
The wiring is considered the roughwork, and the fix-
tures are considered the finishwork. The wiring will usually
be concealed in a conduit, which is installed throughout the
building as it is erected. The wiring is pulled through the
conduit much later in the job. Cable is also used extensively
(almost exclusively on residential projects). Cables are
installed when the building is being erected. The fixtures are
usually the last items to go into the building, often after the
interior finish work is complete.
To work up an estimate, estimators go through the
plans and specifications in a systematic manner, taking
each different item and counting the number of each. Every
item must be kept separate. For example, floor outlets are
different from wall outlets. The estimator must not hesitate
to check off (lightly) each item as they count it to reduce
the possibility of estimating the same item twice. Included
in the list are all outlets, floor plugs, distribution panels,
junction boxes, lighting panels, telephone boxes, switches,ELECTRICAL
CHAPTER SEVENTEEN