Coordination Drawings

Introduction: 

Coordination (sometimes called Composite) is critical to the success of any commercial or institutional building project today. Coordination in construction once referred to simply avoiding physical conflicts in the layout of equipment in spaces and the routing of duct, piping, and raceway systems through buildings. The risk of interference problems is highest on building projects that have intense mechanical, electrical, and plumbing (MEP) requirements. Production risks are compounded, as schedules become more intense. Eliminating coordination problems can be characterized as a prerequisite to the start of construction work on intense projects with dense MEP system requirements.


Coordination drawings definition: see fig.1

 

fig (1): Coordination (Composite) Drawing

Coordination drawings are Reproducible drawings showing work with horizontal and vertical dimensions to avoid interference with structural framing, ceilings, partitions, equipment, lights, mechanical, electrical, conveying systems, and other services:

• in and above ceilings. 
• within walls. 
• within chases. 
• in mechanical spaces. 
• in electrical spaces. 

Coordination drawings are mainly developed for sheet metal contractors, electrical contractors, mechanical contractors, and mechanical engineering consultants.



The purpose of coordination drawings: see fig.2

• The coordination process is performed to allow each trade to compare the materials that are intended for given spaces in a building to ensure they will not conflict physically, or impair the installation and maintenance of subsequent systems.

• Highlights plan discrepancies and missing/insufficient information provision. Allows contractors to effectively construct the project, with minimal time lost from the need to seek additional information or clarification from other parties. 

fig (3): Purposes of Coordination drawings

• Allow better estimation of cost & time in the schedule of works, and hence smoother workflow. 

• Frees up site staff to concentrate on more important key tasks instead of wasting time doing minor coordination tasks. 

• Reduce misunderstanding between the various parties involved in a project since everyone possesses the same development plans. 

Responsibility for issuing coordination drawings:see fig.3

• In current practice, Contractor/Subcontractors produce coordination drawings including plans and sections for structure & MEP works. 

• Such process is controlled and managed by a single coordinator in less complex projects or by coordination team in complex projects. 

• The coordinator / coordination team may be/include the Construction manager, the general contractor, design consultant or one of the construction team such as the HVAC contractor. 

• A final conclusion is that all project parties are participating in issuing and creation of coordination drawings. 

fig (3): Coordination drawings development team

Coordination drawing Creation procedures: see fig.4

• A single set of CAD drawings are developed for the space using electronic data files supplied by the consultant or developed by a member of the construction team from the construction contract documents. These CAD drawings would typically be three-dimensional for this purpose. 

• The coordination team decides as a group the assigned order in which the coordination work is to take place. The specialty contractors with building services that need to be fabricated and are sensitive to routing such as the HVAC air distribution system should start first. 

• The drawings pass from each specialty contractor to the next in the agreed to sequence. Each specialty contractor includes its work on the shared drawings. This can be accomplished by assigning each specialty contractor a specific CAD drawing layer. 

fig (4): Coordination drawings development Flow Chart

• If a specialty contractor encounters a conflict or problem with the work of a previous specialty contractor, the previous specialty contractor is contacted and the issue is resolved between them. If the two specialty contractors can’t resolve the conflict or problem then all of the specialty contractors working in the shared space should get involved to find a shared solution. If the group cannot resolve the conflict or problem, the General Contractor/Construction Manager should get involved along with the owner and/or design team where appropriate. 

• When the last specialty contractor has put its systems on the common drawings, it is assumed that all specialty contractors working in the shared space are in agreement and work can begin in the order dictated by the coordination drawings. 

• If there is a conflict during installation, the conflict is worked out between the specialty contractors with conflicting installations or the group as a whole. 

• Based on the coordinated installation plan, prepare a work plan that includes a schedule and sequence of work for the space. 

• Oversee the work as it is being performed to ensure that all specialty contractors adhere to the installation and work plans. 

• Prepare a record drawing for space as required by the construction agreement after the installation is complete. 

fig (5): Coordination drawings as 3D format

Note:
New technologies such as 3D and 4D modeling (see fig.5) promise to improve design coordination efforts by making design conflicts more visible to designers and construction planners. In isolated cases these technologies have yielded great benefit to users, but are currently perceived to be too costly for widespread use by building contractors.



In the next topic, I will explain another type of drawings which will be the record drawings.please, keep following.