Contract / Construction Drawings




Contract Drawings Definition: see fig.1


It means the set of drawings that form a part of the legal contract for services between two or more parties and which have been signed by or on behalf of the Parties to this Contract.


fig (1): Contract Drawing

It typically include of plans, elevations, sections, diagrams, details of several projections, isometric and perspective drawings.


Contract drawings requirements:


1- Drawings should indicate the relationship between elements of the facility and may designate the following for each material, assembly, component, and accessory:

  • Location of each material, assembly, component, and accessory.
  • Identification of components and pieces of equipment.
  • Give dimensions of components and sizes of field assembly components.
  • Indicate interfaces and connections between materials, detail assemblies and diagram systems.
  • Show forms and relationship of building elements.
  • Indicate limits of work and as applicable indicate areas of construction phases 
  • Indicate extent of alternates and indicate “base bid” and “alternate bid” construction so that the scope of each condition is clear. 
  • Indicate work to be performed by or for the owner under separate contracts. 
  • Identify applicable drawing symbols in schedule of symbols.
  • Indicate the graphic scale of drawings.

2- Contract (construction) drawings should embody the same requirements as for specifications; should be fair, realistic, current, consistent, concise, clear, and, precise.

3- They must be sufficiently detailed to show the location and extent of the work; those from which the contractor obtained information to submit the tender, and related to the other contract documents

4- Ideally, the contract drawings should include every drawing prepared for the work. In practice, this is not always possible, but if drawings and specifications are being used to obtain tenders, the drawings must be detailed enough to allow the contractor to carry out its own taking off. If bills of quantities are provided, small details may be omitted from the drawings provided they are included in the bills of quantities.



Contract drawings arrangement: 


The usual way of arranging the different types of Contract (construction) drawings in building construction is in the following order:

  • Titles, legends. 
  • Demolition drawings. 
  • Site drawings. 
  • Topographic survey. 
  • Soil boring data. 
  • Site demolition. 
  • Civil. 
  • Landscape. 
  • Architectural drawings.. 
  • Structural drawings. 
  • Plumbing. 
  • Fire protection. 
  • HVAC. 
  • Electrical.
  • Standard details. 

Contract drawings must contain all data required by city, county, federal and governmental authorities guidelines.

The contract drawings are to be noted by number in designated place in the first recital. Occasionally, there is some disagreement over the number and type of drawings to be designated contract drawings.

The contract drawings must be signed and dated by both parties, this means every separate drawing. an endorsement on each document should read:” this is one of the contract documents referred to in the agreement dated ……” or other words to the same effect.

The further drawings and details which the consultant/engineer is to provide are not contract documents, if they show different or additional or less work and materials than are shown on the contract drawings, the contractor will be entitled to a variation.



Contact Drawings Importance and priority:


If a dispute arises, and it is necessary to discover what was agreed between the parties, the arbitrator or the court will look at the contract documents including drawings.

In various places throughout the contract reference is made to work being or not being in accordance with what is contained in the contract documents including drawings a problem is arises if the documents are in conflict, we must see the priority of documents selected by the consultant which must be followed.


Contractor responsibility for contract drawings: 


  • Check all drawings furnished immediately upon receipt 
  • Compare all drawings and verify the figures before laying out the work 
  • Promptly notify the Contracting Officer of any discrepancies 
  • Be responsible for any errors that might have been avoided by checking all drawings 
  • Reproduce and print contract drawings and specifications as needed 


Contact Drawings and specifications Relation:
 see fig.2


fig (2): Specifications


They must be read together, provided that no quatites are shown. If there is a conflict, the drawings are to be given preference over the specifications or work schedules . if the quantites are shwon for some iteams, thise quantites will prevail.



fig (3): Construction Process Movie

In board terms, the contract drawings are graphical depictions, and the contract specifications are written description of the end result of the work to be performed. If we assume that The construction process is as a movie (see fig.3) then the contract drawings are like the video portion while the specifications will be the audio portion, both are necessary for understanding the movie.



Contract Drawings and bill of quantities Relation:
 see fig.4

The quality and quantity of work shown in the bill of quantites will prevail; If the quantites are mentioned in contract so the contractor will price according to these quantites but if not the contractor must price for every thing included in the contract documents.



fig (4): Bill of Quantities

For more information about the contract/construction drawings please see included in the electrical drawing course ED-1 , Article : Construction Drawings

in the next topic, we will talk about other drawing type which called " Record Drawings".

2 comments:

  1. If you are thinking about a possible renovation or construction project for your home, you may be wondering where you should begin. It is important to know that local By-laws & regulations govern the process, if the proposed project meets certain criteria. According to the City of Toronto, you will need a building permit if you plan to:

    -Construct a new building
    -Any addition to an existing building
    -Structural alterations
    -Renovate, repair or add to a building
    -Demolish or remove all or a portion of a building
    -Change a building's use
    -Install, change, or remove partitions and load bearing walls
    -Make new openings for, or change the size of, doors and windows
    -Build a garage, balcony or deck
    -Excavate a basement or construct a foundation
    -Install or modify heating, plumbing or air-conditioning systems
    -Install or reconstruct chimneys or fireplaces
    -An accessory structure larger than 108 sq. ft. in area
    -A deck more than 24" above ground
    -A wood burning stove/fireplace installation
    -A basement entrance
    -A Second Suite
    -New or altered plumbing

    Mark from Electrical Construction


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