Assurance that a building is delivered and performs as designed (and meets owner’s expectations) when occupied, is a popular response to the question as to why an owner contracts for commissioning services. The quality assurance function of reviewing, verifying, and documenting each step in the design and construction process is, in essence, “commissioning” which will document the final status of the building systems delivered. The problem is that most buildings are “delivered” in stages: Substantial Completion, Occupancy, Final Completion, and the time line of these stages can vary widely.

This paper will describe the completion stages of a 420,000 square foot laboratory building and focus on the five key elements of building construction completion:
installation, start-up, control, balance, and performance verification.

The paper will delve into the relationship and resulting impact of the overlap of these five completion elements with the three stages of completion, as well as the resulting benefit to having commissioning as part of the process.

Introduction: Expectations vs. Reality

To occupy a building that has been functionally completed with all components and systems fully installed, started, controlled, balanced, and tested upon occupancy seems to be a reasonable owner’s expectation and goal when commencing a new construction project.

The owner’s design team builds this expectation into the project contract requirements in the form of the project specifications, which along with the design drawings become the project contract documents.
The construction team agrees to fulfill the intent of the contract documents and creates a project schedule that reflects both the contract document requirements and owner’s occupancy requirements. It should be noted that an owner’s occupancy expectation and construction team schedule might include a phased occupancy based on owner needs and the construction practicality of meeting those needs. In any event, the construction schedule normally includes the start and completion of all facets of the physical construction requirements prior to the occupancy target.

Therefore, the owner upon signing the construction contract has essentially secured a “promise” that the construction team will deliver the building depicted in the contract documents1, with the expectation of construction completion prior to occupancy. Unfortunately, it is rare that contract conformance and owner occupancy are completed simultaneously as planned.

Stages of Completion

EH&E’s experience is that most buildings are occupied prior to all systems being complete. It should also be noted that there is a difference between systems being operational and systems performing to their final design requirements. Therefore, it’s important to discuss the various stages of construction completion:
Substantial Completion, Occupancy, and Final Completion.

Substantial Completion
The definition of substantial completion will vary, depending on perspective of the general contractor and the building owner.

General Contractor – In the latter stages of the construction project, the focus of the construction team is on securing the Certificate of Occupancy (C of O) and the GC generally considers that the project is substantially complete when the C of O is secured. Generally, the requirement for a C of O is that all major equipment is in place and operational and all architectural elements and finishes are complete. The key items for sign-off by the jurisdictional authority to issue an occupancy permit are life safety, power, and ventilation.

Owner — In most cases, the owner would also say that "substantial completion" is attained when the certificate of occupancy is acquired. The owner’s thought process normally appears to be that when the building is “functional” and acceptable to the local code officials having jurisdiction, then the building is substantially complete and all outstanding issues become “punch list” items.

An additional owner expectation associated with substantial completion is that all training and operations and maintenance (O&M) manual requirements be contractually completed. The importance of thorough staff training on all building elements and systems as well as complete O&M manuals cannot be underestimated. It is imperative that clarity of system design and proper maintenance protocols are transferred to the owner’s staff, if optimum performance is to be sustained over the life of the project.

(Note: Although this knowledge transfer cannot be underestimated in relation to building and system performance after occupancy, this paper is primarily focused on issues related to the physical construction completion. Therefore, training and O&M will not be further addressed.)

Commissioning Engineer — Substantial completion is attained when all of the following have been completed:
1. All architectural elements and functions have been completed.
2. All contractual obligations for equipment and system installation of the mechanical, electrical, plumbing, life-safety, and fire protection systems iscompleted, inclusive of:
a. Equipment installation – 100%.
b. Equipment start-up, including completed start-up reports.
c. Controls completion, including completed “point-to-point” check-out
d. Complete air and water system balancing reports.

Since commissioning is essentially an “acceptance process,” inherently commissioned systems need to be “complete” with limited and defined punch list issues. There is credence to all three perspectives. In some cases all three perspectives are in alignment, i.e., all prerequisites for the commissioning acceptance process are fulfilled at the time the C of O is issued. However, on large, complex projects this is usually not the case.

As discussed in relation to the acquisition of an occupancy permit, certain tangible aspects of the building must be complete prior to occupancy, but intangible contractual deliverables such as air and water balancing, final and optimal system control, staff training, and document transfer to the owner’s staff may not be complete.

Unfortunately, in many cases, an owner’s occupancy schedule includes constraints that do not allow for additional time required by construction delays, regardless of the reason for those delays. Performance shortfalls, such as insufficient air distribution to certain end-use spaces or failed reheat coil operation, could easily go undetected prior to occupancy, but will contribute to excessive maintenance calls upon occupancy.

However, blatant failures will be noticeable, while performance shortfalls such as inadequate air or water flow may not be as easily detectable under certain load conditions. Also, system completion will generally cause disruptions and complaints from the occupants due to potential system isolation and/or shutdowns during occupied hours.

System “final” is a milestone signifying that the system is 100% installed,
started, controlled and balanced, and ready for owner acceptance.

When the opportunity exists, it’s important to complete and commission all aspects of a system prior to occupancy to ensure designed performance.

Occupancy prior to system completion will risk:

  • Generating occupant complaints.
  • Disruptions to the occupants while work is being completed.
  • Never fully completing the system that was contracted for.
  • Occupant perception of the new facility as a “bad building.”

Final Completion
System “final” is a milestone signifying that the system is 100% installed, started, controlled and balanced, and ready for owner acceptance. All known punch list items should be complete. In actuality, the term “final completion” is redundant. The fact that final completion is normal jargon on construction projects is a good indicator of the complications system completion presents.

Reality of Occupancy Needs Spurs Modifications

Most building systems are not complete upon occupancy, mainly because they can be occupied without being “complete,” as previously described. As “beauty is in the eye of the beholder,” so too is “completion in the eye of the needy,” with “needy” defined as “those with a specific occupancy requirement.” Something short of complete, but perceived as “close” to complete becomes acceptable when an occupancy date is immovable.

Unfortunately, most building system performance shortfalls will become evident upon or during occupancy. An occupant will be exposed to heating or cooling deficiencies, and any anomalies related to power, lighting, process, or thermal comfort (i.e., anything that they can physically sense).

Technically, if a system is not complete, it’s not ready to be commissioned (performance/acceptance tested). However, to avoid the building owner being inundated with complaints upon occupancy of a building with incomplete and untested systems, we will modify the commissioning scope and process to test “move-in” status of systems and room conditions. This scope modification is intended to improve system reliability for the building occupants by identifying system shortfalls existing under the move-in conditions.

My experience in Massachusetts is that the applicable municipal inspectors are fairly stringent in their sign-off requirements for electrical, fire alarm, fire protection, and life-safety systems. These inspectors request necessary documentation and witness system demonstrations of specific building systems. The “sign-off” of these officials is essential in getting the owner a building occupancy permit or at least a conditional “temporary occupancy permit” pending the completion of specific corrective or completion issues.

HVAC Considerations
What does not currently fall into the category of a municipal official’s final “signoff” is the building’s heating, ventilating, and air-conditioning (HVAC) system, except where these systems are an integral part of those systems requiring municipal jurisdictional sign-off such as the ventilation required for stair pressurization or smoke evacuation where applicable.

So, from the contractor’s stand-point, the building is “substantially complete” when the occupancy permit requirements have been met. Most owners generally agree, with the understanding that the “punch-list” will be completed.

However, from a commissioning perspective, Substantial Completion would require that all components and subsystems of the HVAC system be documented that they have been completed, started, fully controlled and balanced per the building’s design intent and contract documents.

Commissioning is a process of quality assurance steps that ultimately documents that equipment and systems meet the requirements of the construction “contract documents:” plans, specifications, and all formally accepted changes. In essence, the commissioning process is an “acceptance” process which inherently would require that building systems are complete (you wouldn’t knowingly accept a system that is not complete). The larger point here is that systems might be
operational but not complete in that these systems may not be meeting the performance requirements specified in the contract documents. For example the performance of an air handling unit (AHU) is dictated by the completion
requirements of every element of the air handling system:

  • Design and specification
  • Purchase
  • Manufacture
  • Installation
  • Ductwork integration
  • Piping integration
  • Fan start-up
  • Controls Integration
  • Air distribution system completion
  • Architectural room level completion
  • Final air and water balancing.

Prior to final controls completion, the air handler may be delivering air quantities to the building but performance functions such as variable volume supply & return, economizer, and face and bypass control may not be performing as designed.

Prior to final system balancing, the air handler is operational but the zones being serviced might be getting uneven air distribution, “hot/cold” spots, or pressurization issues. In these two examples the air handling unit is operational, but far from finished. Until completed, the building in most cases will experience problems and occupant complaints, regardless of the existence of a building permit.