Cost control for microelectronic, MEMS and nanotechnology facilities
10/01/2006
Understanding total costs early on is key to successful cost control
By Dana Watts, AIA, and Mark O’Brien, PE, Symmes Maini & McKee Associates, Inc.
Managing the design, construction, and operations costs of microelectronics, MEMS, and nanotechnology facilities is never easy. But it is likelier to be achieved if all stakeholders-owner, user, operator, design team, and builder-understand the total cost story early in the game. Four essential elements of cost control understanding and success are:
■ Knowing the true cost of a facility, considering not only initial costs, but also life cycle costs
■ Understanding the design drivers and their effect on cost
■ Understanding the impact of systems on cost
■ Developing a cost strategy for making effective budget decisions
True costs
With unpredictable materials and labor costs being the norm today, the challenge of setting a predictable budget grows tougher. Knowing where the costs fall is an essential first step in overcoming the challenge, and first costs and life costs both merit attention.
Decisions made in the planning and design stages not only affect initial cost, but also have a much greater impact on the overall cost of operating the facility over time.
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During a twenty-year use period the operational cost of an advanced technology facility may approach seven times the cost of initial construction (see Fig. 1). As the diagram illustrates, operational costs, along with building maintenance, account for much of the true cost. By contrast, initial design and construction represent only roughly ten percent of the true life cycle costs. Clearly, the greatest opportunity for savings rests in the building systems operation and maintenance. Making the right design decisions up front will reduce the overall life cycle costs of a facility.
Many of these decisions relate to engineering systems. Cost data analyzed from several advanced technology facilities reveal that the preponderance of a project’s initial costs are in mechanical, electrical and process systems, and to a lesser degree in cleanroom construction. These critical decision areas have the greatest impact on the lifetime cost of the facility.
At the Ohio State University, a call for more than 19,000 square feet of cleanroom and research facilities was made after construction had begun on a new building. The fit-up would be used in the research of bio-MEMS devices for drug delivery within the human body to combat cancer and diabetes. The elements of the building included:
■ Two-story facility, all-steel structure, slab on grade
■ Masonry, glass, and metal panel exterior skin
■ 4,100-square-foot laboratory, 3,200-square-foot office area on the first floor
■ 7,300-square-foot bay-and-chase Class 100 (ISO Class 5) cleanroom suite on the second floor
■ Rooftop, steel-grillage-supported make-up air and recirculating air-handling units, in addition to process exhaust fans
■ Acceleration of a future 10,615-square-foot addition that would be utilized as a central utility plant
Facility costs for this project, completed in 2005, are summarized in Table 1, relative to total project budget.
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Over 50 percent of the first cost of advanced technology facilities is tied up in HVAC, process piping, plumbing and electrical construction. These systems also represent close to 100 percent of the operating cost for the facility.
Design drivers
Managing the cost of engineering systems and beginning the process of cost control require the planning team to gain control over critical design drivers.
Process
The research and/or manufacturing process that the facility is being designed to achieve determines the required level of cleanliness and the necessary sophistication of mechanical and process systems. They in turn drive design and cost.
Programming
A successful programming process is a powerful cost control tool. By developing a clear definition of the project’s requirements, and advancing that definition to a set of consensus-driven solutions, the essential cost areas become known while the nonessential ones can be eliminated.
Budget
Techniques for establishing a budget vary greatly depending on project size, complexity and timing. The sooner a budget reflects a clear picture of the full scope and detail of what is to be built, the more valuable it is as a cost control tool.
The budgeting process is likelier to be a more effective design driver if it includes:
■ Rolling cost estimates or models that are detailed by specific items of materials and installation scopes of work, consistently updated for each phase of the design process
■ Engagement of cost consultants, outside estimators, or construction managers to develop and check estimates
■ Operating cost data to assist in the decision-making process
■ Necessary soft costs
■ Allowance for cost escalation on projects that have a significant construction timeline
Budgeting can rely on a variety of approaches, with the differences among these approaches determined by the level of detail applied. The broad-brush approach, and typically the least valuable for clean facilities, applies a cost-per-square-foot formula based on historic data. More detail is brought to light in a space-type model, in which specific types of space-such as cleanrooms and labs-are studied for specific cost impact. A detailed budget model, one using a line-item format covering every element, is the only way to establish a true picture of cost.
Codes/safety
Building codes and regulatory requirements also drive design. Zoning laws, environmental regulations, fire protection standards, local ordinances, insurance regulations, and other external requirements can vary significantly from one state or city to the next.
Micro- and nanotechnology facilities, while not necessarily hazardous themselves, often use hazardous production materials in their research or fabrication processes, triggering additional code applications. Building codes can limit the facility’s size or its internal egress travel distance, and they can expand requirements for fire and life-safety protection.
Systems impact on facility cost
Architectural and engineering fees for a typical advanced technology facility represent just a tenth of one percent of its 20-year life cycle cost. Critical decisions made by the team during the design process will dictate the cost of production, utilities, and operations/maintenance costs long after the ribbon is cut.
Energy and water costs
Most of the operations cost is attributed to energy consumption: gas, oil and electricity. Power costs are directly related to HVAC equipment, process equipment/tools, interior lighting, and site lighting, determined by user needs and by design.
The expense of water, the other major contributor to the operational cost, has risen dramatically in most regions. In advanced technology facilities, water demands are high due to the need to supply DI systems and provide cooling tower make-up. Even a small DI system with a 100-gallon-per-minute (gpm) recirculating flow rate will use approximately 1.3 million gallons per year, depending upon process tool requirements.
Cooling tower make-up accounts for approximately 3 to 5 percent of recirculated water flow. On a 600-ton tower/cooling load, the peak make-up water flow, due to drift and evaporation, is 72 gpm. This can translate into substantial annual water costs in regions with high water and sewer rates.
Decisions about utilities require project teams to look beyond first costs of equipment and systems, and to evaluate the long-term costs and/or savings of each system option.
Environment control
The level of cleanliness and specifications for humidity and temperature control of a facility impact both first cost and long-term costs.
A conventional bay-and-chase design provides multiple bays with discrete environments. Each bay can have its own cleanliness level and spec for temperature and humidity. This approach is especially effective for uses and functions that demand environments at Class 1,000 (ISO Class 6) and below.
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A microenvironment design (see Fig. 2) is an option for functions requiring over Class 1,000 (ISO Class 6), and often for cleaner environments as well. In a microenvironment, the higher cleanliness level is contained within a larger, less clean space. This approach provides the owner with a lower operating cost for the critical clean space by piggybacking on the required pressurization, temperature, and humidity control of the larger area.
Knowing the options for cleanliness level, and working to ensure the selection of the appropriate level, helps avoid both first-cost and long-term-cost overruns.
Infrastructure
As noted earlier, more than half the first cost and almost all the operating cost of an advanced tech facility are attributable to engineering systems.
Capacity was a critical element during the renovation of an existing microelectronics fabrication facility for Analog Devices. The result was a savings in both first cost and long-term operations costs. By focusing on use-specific requirements, rather than on industry metrics, the design team was able to reduce the size of a make-up air unit from 50,000 cfm to 30,000 cfm. Because this was a 100 percent outdoor unit in the Northeast, the total reduction in cooling capacity was approximately 200 tons. First-cost savings from the reduction included:
■ $100,000 for the make-up air unit
■ $50,000 for the smaller chiller and cooling tower
■ $50,000 for a smaller boiler plant
By reducing the size by 20,000 cfm, this single design modification provided the owner with an immediate cost avoidance of $200,000. Smaller yet tangible savings would be realized in pump sizes and piping/insulation costs.
Long-term, the energy savings from downsizing the chiller alone was projected to be 10 percent per year, based on the use of a fully loaded 400-ton chiller as opposed to a partially loaded 600-ton machine.
Infrastructure location also affects cost. Make-up air units, recirculation units, exhaust fans and abatement devices, such as fume scrubbers, all require regular maintenance. It is important to determine a convenient location and assess the cost impact of that location.
Placing equipment on the roof is acceptable in some climates. However, in northern climates, performing regular maintenance in harsh winter conditions is difficult.
On the other hand, the cost of constructing a fan-deck level into a building is considerably more expensive than a rooftop location. First cost and ease of maintenance must be carefully weighed.
Building energy management systems can be designed to improve operations and energy efficiency. Direct Digital Control (DDC) performs the control logic, but these systems can be complex and proprietary.
Because the DDC control system will represent a first cost of approximately 15 to 20 percent of the HVAC system costs, partnering with a qualified DDC vendor during the design process is recommended. The vendor should be one that is either familiar with the owner’s facilities or one interviewed and selected by the project stakeholders. The cost benefits of this partnership are reflected both in first costs and in long-term costs. The owner’s facilities group develops an ongoing understanding of the DDC system they will operate, minimizing their learning curve. In addition, the DDC vendor brings added operational-cost-saving ideas to the table during design.
Future flexibility
Designing flexibility into a facility can reduce future design and construction burdens, but can add considerably to the first cost.
Frequently considered approaches to flexibility include:
■ Adding a general/unassigned clean bay to accommodate future expansion
■ Building a Class 1,000 (ISO Class 6) space now that can be upgraded to a Class 100 (ISO Class 5), should process needs change
■ Providing N+1 redundancy on many systems
Because such ambitious flexibility options, especially those involving unassigned space, fall victim to cost cutting, it’s important during cost modeling to be thorough and to project all future cost savings of these features as accurately as possible.
Not all flexibility approaches are expensive, however. Installing two 100 percent capacity supply fans in a make-up air unit, operating both of them normally, and allowing one to ramp up in case the other fails, provides an affordable redundancy. Similarly, installation of certain construction elements, such as required roof penetrations or valved and capped hydronic services, are low first-cost elements that will ease future fit-up changes and save time.
Strategies for true control
Several key strategies aid in accurately predicting the cost of the project, including stakeholder involvement and schedule acceleration.
Stakeholder involvement
Involving as many stakeholders as possible in the development of the cost model increases the relevance and acceptability of the cost model itself.
The owner, user, the architect/engineer, and construction manager develop a clear definition of the project’s requirements, advance that definition to a set of consensus-driven solutions, identify essential cost areas, and eliminate nonessential ones. The team creates the cost model, refines previous assumptions, and tests the results against what they know about the project’s business purpose.
All other key stakeholders need to be brought into the cost model process. With each new participant, the specificity, and hence the value, of the model increases. Such players include:
■ End users
■ Facility maintenance staff
■ Subcontractors (especially mechanical and electrical)
■ Commissioning agent
The use of detailed cost models dictates a vigilant approach, and the recommended strategy of team member involvement promotes the idea behind the strategy: to be as detailed as possible within the limits of available information.
The second part of this strategy is to continually review and update the cost model as more accurate and better developed information becomes available. At each review milestone, the team must take the time to make sure the cost model remains appropriate and accurate for the current stage. These reviews also help to ensure that all project stakeholders are buying in. Questions that should be addressed at each review include:
■ Is the scope of work correct and up-to-date?
■ Is the quality level of the specified materials appropriate?
■ Are changes in materials or equipment being consistently worked into the model?
Schedule acceleration
The saying “Time is money” is never more applicable than in the construction industry. Different systems can be used to accelerate the project’s delivery and therefore reduce costs. There are, however, risks involved with each modification to the delivery method. The greater the opportunity to save time, the greater the risk to be managed. Keys to controlling cost from a scheduling perspective include:
■ Developing a detailed schedule for the design phase and construction phase together
■ Consistently monitoring and updating the schedule as the project progresses
Summary
Every project presents the possibility of both achieving cost control and meeting the exacting needs of advanced technology clients. By understanding where the most significant costs truly lie, and by working collaboratively with all stakeholders on a sustained cost management mission, the resulting facility can perform as needed on its opening day and on into a long life cycle-without inflating the project budget.
Dana Watts, AIA, is a principal at SMMA. He has overall responsibility for the architectural/engineering design and production team, from conceptual to final design and through construction administration.
Mark O’Brien, PE, is an associate principal and chief mechanical engineer at SMMA. He provides engineering and design services through all project phases for SMMA’s Corporate/Commercial, Science Technology + Health, and Institutional practice groups.