Including budget contingencies for overruns, anticipating unexpected challenges, using lower-quality materials, and reducing the scope of a project are no longer the most practical ways to address rising costs. Today, a fresh way of thinking and planning must be implemented as part of a new design paradigm.

“From the time you budget the project until the time you design and then construct, the cost escalation often takes over some of the budget and you have to retreat by reducing the scope, the completion time, or the amount of programming,” say J. Erik Mollo-Christensen, a principal at Tsoi/Kobus & Associates Inc. in Cambridge, Mass., and William Flemming, a senior vice president at Skanska USA.

Information provided by Skanska USA shows that cost escalation relevant to construction and design climbed from two percent in 1990 to more than 10 percent in 2004, and then decreased to slightly more than six percent in 2006.

Using Shell Space as a Hedge

The advantages of shell space in a vivarium, for example, include reduced initial capital cost, permitting the construction of a larger building without fitting out the entire structure. This results in a lower cost for equipment and caging. It may also allow occupancy to occur earlier since there is a reduced construction schedule and a decreased amount of fit-out occurring at any given time.

“Shell space can be used as a strategic way to plan for the future without spending all of your money upfront,” says Flemming.

Shell space also enables designers to hedge their bets relevant to programming, especially on projects where information about the type of research and the number of animals is purely speculative.

On the other hand, there are obvious disadvantages of shell space. For example, it increases the total cost, while decreasing the cost efficiency.

“For a phased project, you have to mobilize the design and construction team a second time,” notes Mollo-Christensen. “You have to pay for additional general conditions to build it later. There is a lack of economy of scale from it and, therefore, there is a decreased cost efficiency.”

There is also the potential disruption of ongoing operations, particularly to the occupied vivarium as a result of construction noise, vibration, and contamination.

Three Degrees of Shell Space

Mollo-Christensen describes three degrees of shell space:  cold, warm, and hot. Cold shell space is basically just the unfinished structure and envelope with no mechanical, electrical, and plumbing distribution systems, no central MEP capacity, and perhaps not even a floor slab if it is on grade. There may be minimal fire protection and lighting. This type of shell has the lowest initial cost and offers the most flexibility, but it requires the greatest amount of disruption, the longest construction time, and the most expensive completion cost.

Warm shell space, which is the most common, includes the structure and envelope with enough MEP systems to supply the space when the time is right for fit out. It requires less fit-out work to complete and involves a medium initial cost, completion expense, disruption, and construction period.

The hot shell is a completed building with finished rooms, but no furniture, fixtures, or equipment.

“Given the cost of caging, you could save a lot of money by not buying cages for the rooms you don’t need,” notes Mollo-Christensen.

The hot shell design requires the highest upfront cost, but results in the lowest completion cost, the least amount of disruption, and the shortest construction time.

It is challenging to construct shell space adjacent to an occupied area and disruptions must be kept to a minimum, especially if a vivarium is located nearby. Appropriate plans must be set into motion to minimize operating disruptions and to avoid disturbing the animals.

The plan should take into consideration connections such as pipes and ductwork. Cross connections should be made in advance in order to avoid the need for future shut-down and rebalancing. A heavy staggered-stud or multiple-layer wall with a sound transmission class rating of 55 to 60, meaning loud sounds are heard faintly or not at all on the other side, should be used to separate the construction area from the occupied space.

“Constructing an interstitial space is also an excellent way to deal with the disruption because you can do the retrofitting and the necessary cross connections outside the vivarium envelope,” says Mollo-Christensen. “When you build a separation wall, you want to carry it up through the interstitial space so it is not penetrated by the construction sounds.”

MEP Considerations

It is important to have adequate main electrical capacity for full build-out because it is extremely difficult and disruptive to retrofit the service at a later date. Providing adequate space for future equipment is imperative, as well as providing sufficient room for air handlers, pumps, chillers, generators, steam/hot water supply sources, exhaust fans, and other equipment. A penthouse may be suitable for the air handlers with roof space to accommodate future exhaust fans.

“If you are on a campus and have connections to central utilities, we recommend sizing those connections to serve the full building,” says Mollo-Christensen. “Size it for the full build-out, even if you are not fitting it out entirely right away.”

There are various incremental approaches to central MEP, ranging from providing space for future air handlers, heating/cooling equipment, and steam/hot water equipment, but deferring installation. Another approach is to incur upfront capital costs by installing all of the equipment initially, but operating it at a reduced capacity.

Cost Considerations

Steps must be taken to ensure the necessary access to the shell space, which should not be located in the center of a site. In terms of cost, access must be provided for construction vehicles, the actual construction, and equipment installation without disturbing ongoing operations and the existing vivarium. Installing the equipment in the future will result in additional costs. The vivarium cost is affected by the availability of specialty subcontractors, the use of new and proprietary scientific equipment, regulations that affect Select Agents, commissioning, and certification.

“You need to think about how to commission the building and how to validate the second phase without causing disruptions,” says Mollo-Christensen. “Set up systems so they are independent from the future systems, but only cross-connected by valves or dampers that could be opened after the second system is running. The use of interstitial space will lessen the likelihood of disrupting user activities.”

The cost savings for shell space is significant, but it is not proportionate to the program. Careful location will minimize future disruption and noise. Building the cagewash room for full capacity in the initial phase and adding more equipment at a later date is prudent, but may result in reduced savings.

It is critical to have a higher than normal design and construction contingency budget in order to plan for the unknown. Mollo-Christensen recommends making the contingency as high as possible, preferably at least 10 percent of the expected construction costs.

Case Studies

When reviewing case studies of constructing shell space, it is essential to consider the criteria used to evaluate shell strategies. These factors include the initial costs, as well as the expense of operating the facility, purchasing equipment and caging, adapting to future technology, and compensating for any operational interruptions.

First Example

The Medical College of Wisconsin/Children’s Research Institute, completed in December 2006, is a 300,000-sf building with a 75,000-sf vivarium. The final construction cost was approximately $109 million with shell space used for 33 percent of the vivarium.

“After the initial design and budget were established, the institution decided to fit out all of the labs. That increased the initial budget from $94 million to $109 million, for an average of $363 per square foot,” notes Mollo-Christensen.

Phase one of the project consisted of building a vivarium to house 10,000 mice and 10,000 rats, with the capacity increasing in the second phase to accommodate a total of 30,000 rodents. The program increment called for two-thirds of the capacity, or about 67 percent, to be built in the initial phase. That actually amounted to about 74 percent of the total square footage and 74 percent of the total cost of $28.7 million for the finished vivarium.

“You do not pay two-thirds and get two-thirds. There is a premium that comes with this and it was about 10 to 15 percent to buy the infrastructure with phase one in order to support phase two in the future,” explains Mollo-Christensen.

This project presented challenges because there were two different institutions—the Children’s Hospital of Wisconsin and the Medical College of Wisconsin—making decisions and the building represented a combination of established and new research programs. Although the vivarium houses only rodents and not mixed species, there are no national growth benchmarks for the rat program since most researchers work with mice.

Another obstacle included a limited construction budget with funding coming from the institutions and state bonds. There is a large potential to recruit top scientists combined with reduced predictability and the uncertain growth for the labs, vivarium, and imaging program.

The building includes a two-level vivarium with a full interstitial over both floors, and walkable surfaces over the aisles. The basement floorplan includes the mechanical room, biocontainment suite, vivarium, support areas, cagewash, and shelled imaging space. The majority of the vivarium space is located on the first floor with additional shelled space at one end of the facility to house rodents in the future. The main corridor was built in phase one to minimize disruption and provide egress.

“We built a separating wall and the corridor wall and we put in doors to all of the suite corridors,” says Mollo-Christensen. “The idea was to build the space and fit it out later. This has a full interstitial at each level which facilitates access to all of the equipment and whatever future cross connections may be necessary.”

When possible, locate shell space on the lowest level to reduce slab noise transmission and keep holding space far away from shell space. In single-story facilities, shell space can be located on the opposite side of the cagewash area.

Second Example

The University of Massachusetts Medical School in Worcester, Mass., is similar in size to the Medical College of Wisconsin/Children’s Research Institute with 360,000 sf and the construction cost is just slightly less at $90 million. However, this building was completed in September 2001 and features a 32,000-sf vivarium. Fifty percent of the lab space remained an empty shell until recruiting was completed and one-third of the vivarium space was shelled. The building, designed and constructed within 28 months, was built with full MEP central capacity.

This project was also completed in phases with the initial part being able to accommodate 18,600 mice cages, or 67 percent of the total 28,000 that would be achieved with the second phase. Building phase one cost $7.4 million, or 80 percent of the total project cost of $9.3 million. The initial investment was higher partially as the result of the inefficiency of having a smaller vivarium.

The medical school is a single-floor facility with a vivarium that includes six holding suites. Each suite contains six holding rooms and two procedure rooms. All of the vivarium support and the cagewash space was built out in the first phase.

Importance of Benchmarking

“Developing benchmarking costs can play an important role in construction projects, but apples-to-apples comparisons must be made between projects in order to obtain an accurate picture and to focus the team on the highest cost areas,” says Flemming.

Only benchmark data between facilities designed for the same use. The best way to make an accurate comparison is to use a net-to-gross multiplier, which will vary depending on project complexity. The project architect or lab planner can usually provide the correct multiplier. If benchmarking different types of projects, such as renovation versus new construction, use the multiplier to convert net square footage to gross square footage.

Benchmarking ensures the design will meet funding capabilities, identifies areas of cost outside the metrics, and helps the design team focus on high-cost areas. The pitfalls of benchmarking involve a reliance on average cost data for decision-making, a possible failure to differentiate between project and design differences, and a lack of comparable facilities. Numbers should be developed around the program, the shell components, location and size of the project, efficiency goals, infrastructure, current trends, and escalation. Flemming recommends square foot costs for each type of space (lab, animal holding, cagewash, office, and support) to develop a more accurate cost model and to enable the project team to adjust the model as the program evolves.

Typically, larger projects are more cost-effective on a square-footage basis. However, both small and large lab/vivarium renovation projects require the same coordination and planning efforts. Costs usually reflect local construction conditions, meaning East and West Coast projects historically command higher construction costs than the South and Midwest. Project size and complexity generally drive the cost scale, but are not the main factors when determining whether costs are likely to be high or low in a specific area.

Vivarium Trends and Cost Escalation

Flemming notes that there are a number of factors that affect vivarium construction costs. The availability of specialty subcontractors is significant; the complex mechanical systems needed for vivaria require special skills, and local trade contractors may not have the capacity or availability needed. Scientific and equipment developments also may affect the cost as the typical design and construction duration may exceed the market cycle of new equipment. The regulatory requirements for vivaria are also evolving, especially with regard to infectious and BSL-3 facilities.

When developing a cost model, remember that user needs define the net square footage and program requirements drive costs. A cost model can be developed to create accurate financials contingent upon variables, including building configuration and egress issues, that are specific to each project. Costs should be based on programmatic data, such as space usage. Next, develop the shell, enclosure, and infrastructure costs that are required to support the programmatic data. System costs should be analyzed, as well, and then the overall building cost data should be compiled and compared.

“Using the appropriate design and construction strategies can make a big difference in the outcome of your projects,” says Flemming. “Benchmarking and cost modeling can be used to help achieve success on your next project.”

By Tracy Carbasho

We welcome your Questions and Comments

Copyright 2008 Tradeline Inc.
All Rights Reserved
ISSN: 1096-4894