ED-1 Course: Shop Drawings – Part Two





Shop drawings submittals classifications:
The consultant shall classify the submitted & not submitted shop drawings into (4) main categories as follows:

  1. Specifying Needed Shop Drawings 
  2. Specifying Unneeded Shop Drawings 
  3. Unspecified Shop Drawings 
  4. Un-submitted and Un-reviewed Shop Drawings 


1- Specifying Needed Shop Drawings:
There is no standard list of trades that must have their shop drawings reviewed. It is still a matter for the professional judgment and discretion of the individual engineer in each unique situation.


2- Specifying Unneeded Shop Drawings:
Unnecessary shop drawings are a wasted effort and expense imposed on the contractor as well as the Consultant/Engineer.


3- Unspecified Shop Drawings:  
If the Engineer does not specify submission of shop drawings for a specific trade, they usually will not be submitted for review. In fact, most Engineers will not accept unspecified shop drawings for review.


4- Un-submitted and Un-reviewed Shop Drawings: 
Engineers should be certain that all specified submittals are actually received from the contractor. It is a good idea to prepare a checklist of all specified submittals at the beginning of the construction period so that each may be checked off as received. The contractor should then be reminded to submit any missing submittals.


Contractor's responsibility in shop drawing development:
  • The contractor is obligated to review and approve all submittals for compliance with information given in the contract documents as well as for suitability to field conditions and dimensions before conveying them to the Consultant/Engineer. 
  • The contractor is required to make such submissions to the Consultant/Engineer with reasonable promptness, in such sequence as to cause no delay in the work, and in accordance with the submission schedule. 
  • The contractor must inform the Consultant/Engineer for any deviations from contract requirements in writing. 
  • The contractor is required to identify specifically in writing any shop drawing revisions other than those requested by the architect on previous submittals. 
  • All the required (specified or not) safety precautions as these are the contractor's responsibility.
  • The contractor will revise and submit all drawings that are conditionally approved, or disapproved to get final approval from the consultant.

Consultant/Engineer’s responsibility in shop drawings approval:
  • The engineer is responsible for ascertaining conformity of the shop drawings with the design concept or the intent of the documents. 
  • The Consultant/Engineer must send the shop drawings back to the general contractor, approved, conditionally approved, or disapproved.
  • If the shop drawings indicate that the work depicted by the contractor will not comply with the intent of the contract drawings and specifications, the Consultant/Engineer has an opportunity to notify the contractor before the costs of fabrication, purchase, or installation have been incurred. 

Notes:

  • The Consultant/Engineer’s approval of a shop drawing does not relieve the contractor of responsibility for meeting requirements of the contract documents. 
  • It is the contractor's responsibility to assure that all work on the job is in conformance with approved shop drawings. 

Improper Use of Shop Drawings
  • Contractors, subcontractors, and suppliers should not use the shop drawings as a means of suggesting substitutions from the contract requirements. 
  • Should it become advisable to recommend changes, the contractor should make specific requests of the Consultant/Engineer, explaining the particulars and the reasons. If it is necessary to deviate from the contract requirements in the shop drawings, then the contractor must point out the deviations at the time of submittal. 
  • If the Consultant/Engineer is deceived into approving shop drawings containing unlabeled deviations, the approval will be void. The Consultant/Engineer’s approval of a contract deviation is valid only when the Consultant/Engineer has approved the specific deviation. 

Did the shop drawings affect the construction cost?

To know the answer for these questions, we need to list the following construction facts

  • Some shop drawing Mistakes have resulted in costly construction defects, tragic personal injuries, and catastrophic loss of life. 
  • Undiscovered mistakes in shop drawings will often lead to unexpected or undesired construction results as well as exorbitant economic claims against Consultants, engineers, and contractors. 
  • It is much more economical to review and correct the shop drawings than to remove and replace erroneous construction. Proper use of the shop drawing review system should prevent costly errors caused by misunderstanding of the contract requirements.


Comparison between shop drawings and construction drawings:



fig.1: Generator room (Construction Drawings)


fig.2: Generator room (Shop Drawings)


Finally, we need to make a Comparison between shop drawings and construction drawings to be sure that both terms are fully understood:



s/n
Construction drawings
Shop drawings
1
It aims to show the general design concept of the project and each of the major components and their relationships to each other (see fig.1)
It aims to illustrate the specific way in which the contractors or the manufacturers will undertake to furnish, fabricate, assemble, or install their scope of works/products.(see fig.2)

2
It acts as a theoretical design concept
It acts as a practical design concept explanation
3
It exists  at the time of the signing of the construction contract
It is developed later after the signing of the construction contract.
4
It is considered as a contract documents
It is not considered as a contract documents
5
It is developed by the consultant/engineer
It is developed & submitted by the contractor / manufacturers.
6
It includes Basic details and dimensions for reference.(see fig.3)
It is fully detailed and fully dimensioned drawings. (see fig 4, 5, 6 & 7)
7
It didn’t permit any deviation from contractual requirements.
The contractor can include some deviations notes with explanation  in shop drawings
8
It must be developed to minimize any contract modifications, change orders and construction change directives as can as possible.
If the deviations from contractual requirements are approved, contract modifications, change orders and construction change directives can occur.
9
It has two revisions only :
1-      90% Construction drawings.
2-      100 % Construction drawings

It has many revisions and the number of these revisions is controlled by getting consultant/engineer’s satisfaction.
10
All the specified works must have construction drawings.
Some of the specified works/products may not need any shop drawings




fig (3): switchboard construction drawings



fig (4,5,6 &7 ): switchboard shop drawings


In the next Topic, I will explain other drawings types like Record drawings. 


 

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