The Inchstone Management Process Can Improve Your Next Construction Project

01/01/2008 |

A new project-management strategy helps owners identify issues affecting system completion early enough in the construction process to correct them

By Michael Della Barba

When beginning a new construction project, the building owner probably expects to occupy a building that's been functionally completed, with all components and systems fully installed, started, controlled, balanced, and tested; however, most commercial buildings today are occupied before all systems are complete, and this overlap invariably has a significant negative impact on both the immediate and lasting performance of the building. Problems manifest themselves in the form of occupant complaints and maintenance costs, as well as in long-term performance deficiencies and higher energy costs. All of these problems and their associated costs are inherited by the building owner.

After carefully analyzing the construction process through many large projects, it was found that much of this negative impact can be avoided through the use of a relatively simple tracking system to monitor specific project deliverables ("inchstones"); these metrics allow building owners to identify the issues affecting system completion early enough in the construction process to correct them.

Maximizing Building Value Using Inchstones
Termed "inchstones" because they work within the existing construction milestones, these indicators are carefully chosen to enable the owner to identify potential delays at points early enough in the schedule to correct, and also to maintain scheduled dates and confirm contract compliance. Inchstones are contractual subtasks with associated tangible deliverables that, if not completely implemented, will directly or indirectly lead to schedule delays and performance shortfalls. Tracking these deliverables during the project provides a finer degree of scheduling oversight for the building owner and gives the project team notification of potential delays early in the project (when corrections can be more easily and inexpensively implemented).

Inchstones are required project deliverables and aren't "additional" requirements. The project deliverables associated with the inchstones are almost always standard components of the contract language in large projects; however, it's recommended that a review of the specification requirements during the design phase be completed to ensure that all critical inchstones (de­­­­liverables) are in place. Examples of project inchstones during the construction phase include: 

  • Submittal requirement sheets and approval tracking. 
  • Contractor plans (installation, start-up, balancing, training, etc.).
  • Point-to-point controls checklists.
  • Start-up notification requirements.

All of these documents contain information critical to the proper specification, installation, and performance of equipment, and should be precursors to the proper start-up, completion, and acceptance of building systems. Consequently, the lack of these key deliverables at certain points in the project should be an early warning that problems will occur later in the construction cycle.

Examples of Inchstone Usage
To illustrate how the inchstone management process can be used to pro­vide enhanced owner value, we reviewed some problems that caused significant delays from recent projects to see how the inchstone proc­ess could have minimized or prevented them via the use of contract documentation. These examples were chosen because they represent two of the most frequent problems (and also because they tend to have the most profound economic impact on the building owner).

Example 1: Equipment start-up deficiencies in a laboratory facility. During the pre-test inspection, it was found that electrical conduits serving the supply fans and penetrating the air-handling unit (AHU) casing were not sealed properly, allowing condensation to form during the summer months and settle in the fan motors. In the 6 months between start-up and repair, significant damage to the motors occurred; the motors eventually failed due to moisture corrosion during the first year of operation and were replaced. This damage was not covered by the warranty. Although replacement costs were covered by the construction team, system failure and ramifications of scheduling shutdowns became the owner's burden.

Figure 1: Number of months post occupancy to performance acceptance (representative of Environmental Health & Engineering Inc.'s project experience).

In addition, functional performance testing identified that outside air dampers weren't fully opening and closing on two of the AHUs. It was later determined that the damper banks were actually "racked" or out of square as a result of improper installation, and there was little the controls contractor could do. Due to time constraints driven by the push for the certificate of occupancy, this deficiency could not be addressed until after occupancy. A later attempt to fix the problem required a shutdown of the AHUs (a huge problem in a fully functioning laboratory facility). In this case, the final determination was that no correction was economically feasible. Therefore, both AHUs continue to operate at a level less than designed and, with the additional strain added to the damper actuators, a shortened life is expected on these components.

The AHU start-up specifications for this laboratory project required a pre-start-up inspection by the manufacturer. Although a start-up procedure for the AHUs was specifically requested, none was received prior to the start-up and only a formal start-up of the AHU supply fans was performed. Both of these noncompliance issues should have been uncovered by the required pre-start-up inspection and would've saved time, money, and client aggravation the first time the units were set in operation per manufacturer and contract document requirements. In this case, the contract-required deliverables (inchstones) would have been receipt and contractor acknowledgement of the procedures prior to start-up, and a completed checklist.

Example 2: Balancing delays in a research facility. Construction rigors and a demanding schedule were the main culprits in starting balancing prior to documenting mechanical and controls completion in this example. Air and water balancing stretched out well into the occupancy period. Implementing balancing on an incomplete system heavily contributed to the delays, which, in turn, led to occupant discomfort, unexpected and intense maintenance activity, and increased energy costs. Although the building received its occupancy permit, the subsequent 4 months until system completion caused a huge strain on the maintenance staff, who responded to occupant complaints and to equipment alarms, often conflicting with the ongoing balancing work.

Although the contract documents clearly defined key tasks to be completed prior to the actual balancing (a detailed review of all tasks and values, associated mechanical and controls equipment, and access to all equipment and balancing ports), much of this preparation was not completed when balancing was scheduled to start.

In this case, one critical inchstone (and a necessary precursor to balancing) was the receipt of the controls point-to-point checkout sheets. The lack of this documentation should've alerted the owner to the problems that would occur during balancing at a time in the project when action might have been taken. Instead, the owner incurred a significant cost in unexpected maintenance and, more importantly, a loss of confidence in the building from the highly vocal researchers who were heavily impacted.

Figure 2: A laboratory building project schedule illustrates the variance in the definition of substantial completion between the general contractor and the commissioning engineer (true substantial completion).

Implementing the Inchstone Management Process
Incorporating inchstones into a construction project isn't a major effort once the inchstones are identified; however, making the process work to its potential involves several important steps that the owner should follow.

  1. Ensure that the contract contains the proper inchstones (deliverables). The first step is to make sure the contract contains the necessary language to ensure that the critical deliverables are required. A contract scan should be completed by a knowledgeable commissioning agent to make certain this is the case.
  2. Make your expectations clear to the construction team. Be upfront with the team about the documentation you require and when the deliverables are expected. Do this at the beginning of the project; give updates at construction meetings regularly. If you don't treat these deliverables with importance, the team won't, either.
  3. Collect, organize, and disseminate deliverables. Have a system to track the deliverables (due date, date received, responsible party, etc.) so you can get a status check when needed. A system that files and records the delivered documents for retrieval is beneficial. Using a Web-based tool for this purpose allows for project customization. Most importantly, allocate time/resources for a person to keep the system current for all meetings. Dedicating a single resource is the most efficient method and requires only a small hourly commitment per week.
  4. Hold the team accountable. You've probably been part of construction meetings where the absence of key deliverables was identified, but no real action was taken. Only the owner holds the power to enforce delivery; therefore, the building owner must be prepared to enforce accountability of team members for the contract deliverables.

Many projects have shown that any time the owner must occupy a new building before all systems have been completed and checked per contract specifications, the owner will add a substantial cost to the project in added maintenance, wasted energy, voided warranties, and a poor building reputation. By implementing a tracking process for key project deliverables spread throughout the building process, the owner can take an active role in minimizing the likelihood of occupancy before systems are fully completed and tested, taking full advantage of the new building. 

Michael Della Barba is director of commissioning services at Newton, MA-based Environmental Health & Engineering Inc. (EH&E), a full-service engineering firm specializing in commercial and institutional building sciences. Find out more at (

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