aQe-

ln order to provide a solution to these probiems, | would
like to suggest consideration of a proposal to provide a
category system of cost estimates, It would be my proposal
that whenever an estimate Is provided to the Public Works
Committee or to Counci!, whether It be for a budget or for
information, that the estimate be accompanied by a statement as
to its category. The use of the category system would aliow
Council to know what standard of reliability to expect from the
astimate.

The rellability limits for Category A of plus or minus 10%
to plus or minus 5% may seem high given that the project has
been “ully designed. However, such a range is quite reasonable
for e type of work which we are dolng. There are two main
reasons why it is virtually Impossible To estimate closer than
this on municipal construction projects.

1. The Unpredictabllity of Soll

No matter how many sol! tests are done there Is no way
to be sure of what will be found under the surfaces
Soll Is not homogeneous. A good example Is the remains
of a corduroy road found under Prairie Avenué. A
contractor would bid on road construction work on a
unit price basis and therefore would get paid extra
whenever he encounters something which was not Inciuded
in the estimated quantities. We have to absorb the

costs.

The Use of Malntenance Crews for Construction

Wwe do not have the tuxury that a contractor has of
assigning a crew, foreman, and equipment until
completion. Our crews must carry out two functions,
their normal maintenance duties as well as
construction. This means a crew or a vital plece of
equlpment [ts often called away from a project for
emergencies. This Increases costs In an unpredictable

WAY

May | have your reactions to this proposal.

F.E. Peters, P, Enge,
City Engineer