click to enlarge Fig. 1. A study examining various building massing configurations and their effect on cooling loads and daylight penetration. All images courtesy of KlingStubbins.

It is probably safe to say that most people would not advocate deliberately damaging the environment, especially if there is no advantage in doing so. But profit and value also play a role in many of the choices we have to make. If the design solutions we advocate to help preserve the natural world are not financially feasible, they are not likely to be implemented. We have to evaluate what our ideas will cost, both initially and in the long term, as well as how well they will work.

Research laboratory buildings represent an exceptional class of construction due to the specialized activities that take place within them and the materials, personnel, and equipment they contain. Costs are high compared with buildings designed simply for user comfort. Because of these higher costs, in energy consumption as well as in construction, labs represent a special challenge and opportunity in sustainable design.

This article depends primarily on a recently published book, Sustainable Design of Research Laboratories, authored by my colleagues at KlingStubbins (Wiley, 2010.) The book contains a depth and breadth of detail only lightly touched on here. I encourage those with further interest to investigate this resource.

Sustainable design
Sustainable construction is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs."¹ Buildings use more than 30% of the total energy and 60% of the electricity consumed in the U.S.² Labs use 5 to 10X as much energy as typical office buildings,³ and can cost twice as much to build, or more, indicating intense resource utilization indeed. So, optimization in the design and use of laboratories can realize significant conservation goals.

The design and construction industry recognizes a number of different standards to guide and promote "green," or "high performance," building design and construction practices, including the U.S. Green Building Council's LEED program, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers' (ASHRAE) energy conservation Standard 90.1, and a British evaluation system called BREEAM, for Buildings Research Establishment Environmental Assessment Method.

click to enlarge Fig. 2. This lab exterior design incorporates patterned and spectrally selective glass and external shading devices to reduce solar gain in south-facing spaces.

The American Institute of Architects is promoting the 2030 Challenge, a proposal for adoption of targets toward reductions in fossil fuel consumption, and Labs21 develops resources for the use of laboratory designers and users aspiring to new standards of environmental performance.⁴ All of these systems help coordinate the efforts and goals of a diverse set of designers and users.⁵

Envelope and orientation
Site constraints, laboratory function, and the context of the facility within the industry (be it developer-built, corporate, institutional or governmental), will all influence the size, shape, and exterior materials of the building. Pharmaceutical global R&D headquarters buildings will emanate prestige and attempt to attract and retain the best scientific talent, while other specialized lab buildings might have a robust but plain exterior, designed to protect the precious, proprietary or hazardous materials and processes within.

To evaluate the financial and environmental impact of design decisions and construction practices, costs of building systems have to be examined over time, in terms of their durability, toxicity, disposal costs, and energy usage, and at the outset of the project. Facilities professionals and design engineers and architects can provide information about longevity, consumption, support, and maintenance, and construction managers, contractors, and estimating consultants can advise on first costs.

Though HVAC is top-of-mind for many lab design teams, a plethora of other factors help determine sustainability. This article examines choices in sitework, envelope, structure/geometry, and organization (levels of specialization and configuration of program elements).

Sitework
Determining the location for a new building or a renovation, with its proximity to raw materials, manufacturing, infrastructure, and potential employees, has a significant impact on its use of resources.⁶ Each site is unique, and issues of parking, environmental remediation, storm water management, etc., can singly or collectively have a large impact on project costs. Sitework commonly ranges from 5% to as much as 25% of project cost. Once a site is selected, earthwork, utility, parking, and other land-development scope can be subjected to cost relationship evaluations, but it is not unusual, for the purposes of building design comparison, to exclude site costs in preliminary studies.

click to enlarge Fig. 3. Relocating some of these consumable supplies would free up space for lab work.

The extent to which the exterior envelope and the conditions within are intertwined requires extensive coordination by the design team for successful results. Concerns about resource utilization and the balance between first costs and energy requirements generate situations that can only be resolved in a rigorously synchronized effort. "Integrated design"—the close, simultaneous interaction of experts in specific aspects of design and function, applied strategically—is "achieving innovation that would otherwise remain undiscovered,"⁷ and has evolved as a superior solution to traditional sequential approaches.

Solar heat loads and desirable natural lighting and views require attention to building orientation (Fig. 1). Where natural ventilation is an option at some or all times of the year, building configuration can be manipulated to enhance these effects and can deliver energy savings at little cost beyond the relatively small premium for operable windows. Increased insulation values in the walls and roof can lead to reduced HVAC requirements, but the increase in cost for better thermal insulation must be weighed against the actual energy savings realized.

Since roof color affects absorption of solar radiation, lighter colored roofing materials, or coatings have proved to be cost-effective modifications, which pay for themselves in energy savings over a relatively short period.⁸

There are several cost-effective responses to improve the thermal performance of glazed areas. External shading devices, spectrally selective and low-emissivity ("low-e") glass, and patterned opaque coatings on glass are all employed to allow penetration of light and views while lowering solar heat gain (Fig. 2). Doublewall facades use two wall planes separated by an air space where air flow is automatically controlled to insulate or ventilate, modulating the performance of the wall. However, it is easy to see how these assemblies might be twice the cost of typical window systems, or more.

click to enlarge Fig. 4. Mechanical service piping located along a central spine is brought to benches via overhead carriers.

There are also active shading systems such as internal louvers that respond automatically to solar conditions, and glass that can be darkened using suspended-particle devices or polymer-dispersed liquid crystal displays. These have been used in limited applications but are currently considered too expensive for most exterior closure systems.⁹

Even where interstitial space is not included, added mechanical systems drive higher floor-to-floor heights, frequently 15 or 16 ft. Including an interstitial area, a single story might be as high as 22 or 25 ft, compared with 12 or 13 ft in a more typical office structure. There is some added structural cost to achieve this added height, but it has a more costly impact in the exterior wall area. With exterior wall systems typically amounting to 50% of the cost of the building shell and structure or more, this 25% increase or even doubling of exterior area represents a profound opportunity for seeking efficiencies in mechanical system arrangement or reduction and for an integrated design process.

Building structure and geometry
No builder will hoist any more dirty, heavy, and potentially dangerous materials like steel and concrete than are required to get the structural job done. Structures are designed to carry the floor and roof loads, support themselves, and to allow the required arrangement of interior spaces. Efficiencies are typically inherent. One characteristic in laboratories that may receive greater attention than in more commonplace structures is a limit on the amount of vibration allowed, due to requirements of sensitive instruments or procedures.

Structural steel produced in electric arc furnaces is typically composed of 90% recycled materials,¹⁰ and is itself recyclable, and concrete reinforcing bars also are almost entirely composed of scrap metal.¹¹ Structural concrete usually has the environmental advantage of being composed largely of materials produced locally, which has the benefit of reducing energy expended in transportation. It can also be crushed and reused as structural fill, road pavement base courses, and asphalt or concrete paving aggregate.¹²

Because of equipment heat loads, extraordinary ventilation requirements, extensive plumbing, and other considerations, research facilities require additional space above the ceiling for ducts, pipes, and so on. Since the work being performed in the lab can be considered so critical that it must not be delayed or compromised by intrusive maintenance procedures, an entire secondary structure of floors or platforms is sometimes constructed above the laboratory ceiling for access to mechanical and electrical systems.

click to enlarge Figs. 5a and 5b. Peak water demand vs. consumption. All images courtesy of KlingStubbins

Level of specialization and configuration
Since the interior spaces in a lab are presumably shaped by the processes and activities performed within, and by the mechanical and electrical systems required to support those occupations, opportunities for optimization of building size and configuration require rigorous examination of assumptions. Opportunities exist in locating shared specialized equipment in a central location, rather than scattering the same function in redundantly dedicated locations, or in installing equipment on a cart that can be relocated as needed.

Removal of equipment and storage functions from the lab environment results in reduction in energy used to counter equipment heat gain, and to needlessly create lab-quality environments in storage areas (Fig. 3).¹³

Reducing the amount of circulation and support space in relation to active program space results in a more efficient building, with less material overall and shorter runs for mechanical and electrical services. Laboratories typically have net program area to gross area ratios in the 45 to 65% range.

As science progresses, future lab requirements cannot be perfectly known. It is sound practice to envision some flexibility in laboratory environments, but excessive adaptability beyond what is actually needed will result in unused capacity. Modular layouts can assist flexibility, but avoid providing every service in every location. One solution (Fig. 4) provides services along a central spine, which are extended into overhead service carriers only as required.¹⁴

Flexible casework and demountable partitions can reduce the demolition and waste required for reconfiguration, but are more expensive than their built-in counterparts. Selecting a flexible casework system can also result in less casework at the outset of the project, as users are more comfortable deferring a requirement for a base cabinet or other element if they know it can easily be added later.¹⁵

Rain water that collects on roofs and paved surfaces is typically channeled to groundwater recharge or detention beds, to moderate peak flows and minimize surges downstream. This water can also be collected and used for irrigation or flushing of toilet fixtures, or, with proper treatment, for other end uses such as in air conditioning cooling towers. Rain water is not, however, a constant and regular water source, so considerations of the material and financial cost of storage and distribution should be weighed against the potential benefits of conservation.¹⁸

click to enlarge Figs. 5a and 5b. Peak water demand vs. consumption. All images courtesy of KlingStubbins

Interior finishes
Laboratory finishes and materials are selected to stand up to high traffic and to minimize maintenance, ease cleaning, and resist caustic chemicals. These are often solutions with higher initial costs, but reductions in lab down time and in frequency of required renovations are considered reasonable trade-offs. Less frequent replacement can have a greater overall impact on sustainability than any amount of recycled material content might have.¹⁶

An example of appropriate material selection would be the decision to equip a lab with regular acoustic ceiling tile, as opposed to a vinyl-faced ACT, if an easily cleaned material is not required. Not only does the typical tile have a lower first cost, but it also usually has a greater proportion of recycled material and is easier to recycle at the end of its useful life. The point is to carefully consider the use of the space to adapt the design to the application most appropriately.¹⁷

Plumbing
Design solutions are used to reduce waste water and to raise water use efficiency, but in many areas water supply is relatively inexpensive and conservation is mandated or motivated by environmental responsibility, rather than by rapid financial payback.

HVAC
Laboratories can consume 5 to 10X the energy of a similarly sized office building (Figs. 6a and 6b).²² This increase is almost entirely due to increased HVAC loads due to ventilation requirements. In a typical office building, air is recirculated, so heating or cooling equipment is working with air that is already tempered, while most labs require 100% outside air, also known as "once through," or "single pass" air, to prevent cross-contamination.²³

"Gray water" collected from potable water uses can also be recycled for landscape irrigation and "can often be used to offset 100% of that demand if proper storage, filtration, and distribution systems are employed." Sources in laboratories include hand washing sinks, glassware washing machines, condensation from air conditioning coils, and water rejected from water purification systems.¹⁹

Peak water demand for different uses, which determines required equipment and flow capacities, may not correspond with total volumes of use. In seeking conservation measures, the targeting of overall consumption should rule over reductions in peak demand. Figs. 5a and 5b illustrate an example of differences between peak usage and overall consumption.²⁰

Pipe materials selections offer sustainable design opportunities as well. Plastics such as PVC, CPVC, and polypropylene, and copper, glass, steel, and cast iron are all potential material choices, each having a different first cost, service life span, and manufacturing environmental load. Plastics are cost-effective and in many cases require less energy to manufacture and install, but are not all recyclable, while metal pipe may last longer and is generally recyclable.²¹ Metal pressure piping systems can be 20 to 50% more costly than plastic, but are often selected in laboratories for reliability and safety reasons.

click to enlarge Figs. 6a and 6b. Distribution of energy use in an office and a laboratory.

The inclusion of such water-saving devices as high-efficiency fixtures, automatic motion sensing faucets and flush valves, and dual-flush valves, with two different flushing quantities supplied for varying demands, are becoming design standards and are frequently required by local or international building codes.

"Adjusting the criteria from eight hoods per module at full flow to four hoods at full flow resulted in a 35% reduction in peak building airflow. This reduction in peak airflow resulted in capital cost savings in the supply air handling units, exhaust fans, boilers, chillers, ductwork, and piping distribution systems, size of outside air intake louvers, and floor-to-floor heights, as well as energy savings attributable to right-sized systems."²⁵

Lab air flow and HVAC design are determined by the load requirements of three different situations: "load-driven," where equipment heat loads (combined with solar gain and occupant loads) control the ventilation; "air change-driven," if quantities needed to dilute concentration of contaminants take priority; and "hood-driven," if the air supply required to make up the air exhausted by fume hoods is greater. These drivers may interact dynamically. In a lab normally controlled by make up air, if the fume hood sashes are closed, equipment cooling make take precedence, and if equipment is not running, dilution quantities might govern.²⁴ Energy savings in labs, in any case, usually include reducing the air flow to the minimum levels for safe and efficient operation.

"Consider a recent chemistry lab that was designed to have eight fume hoods per lab module, each occupied by four researchers. There were a large number of modules, and preliminary calculation of the air handling system size indicated a huge amount of air required to accommodate the hoods in a fully open position.

"The team was alerted to the considerable capital costs of the air handling systems, as well as ductwork distribution, space for the equipment, and supporting chilled water, steam, and electric infrastructure. Challenging the criteria that all fume hoods could operate simultaneously initially received some disapproval from the scientists, who were concerned about limiting their research flexibility. However, review of operations in similar existing labs indicated that no more than four of the eight hoods were ever simultaneously open.

click to enlarge Figs. 6a and 6b. Distribution of energy use in an office and a laboratory.

Physical strategies to reduce energy consumption in labs are numerous, and new approaches are continually being developed. Many have associated increases in initial system costs, which must be balanced against savings in energy over the life of the system.

Dynamic variable air volume systems have automatic controls that calculate the air flow requirements in each space due to the three drivers above and increase or reduce the main air moving equipment volumes accordingly. Higher efficiency fans and more rigorous duct leakage standards result in more efficient air distribution. Chilled beams, like cold water radiators mounted in the ceiling, provide decentralized cooling, allowing a lower volume of air, at a higher temperature, to be delivered to the labs, so ductwork can be reduced and floor to floor heights lowered. Heat recovery systems extract heat from the exhaust air stream to assist heating in the winter, or from the outside air intake, for cooling in summer.²⁶

Technologies available to deliver low energy cooling and heating include water-cooled, geothermal, or hybrid heat pumps, which use evaporation, the stable temperature below the surface of the earth, or a combination. Heat exchangers, compressors, and evaporators reject heat into the building when heating is required or outside when cooling is needed, rather than producing the temperature changes required through sheer mechanical power. Heat pumps are typically smaller units distributed in a decentralized manner, and ductwork quantity is thereby reduced.²⁷

Electrical
Energy savings and sustainable design strategies in laboratory power systems are confined mainly to inquiries into the reduction of the HVAC equipment energy requirements as described above, but lighting requirements can also be targeted. Artificial light can be combined with light entering the building from outside in utilization and control schemes known as "daylighting" or "daylight harvesting" (Fig. 7).

Use of natural lighting for illumination of workplaces can result in some energy savings due to reduced use of electric lights, but direct sunlight falling onto working surfaces produces glare. Diffuse light is required, and this can be obtained through exterior shading, coatings on window glass, or by shaping the exterior of the building or the interior areas where the light enters to provide light-colored surfaces that are struck by the direct beams and reflect them into the space. There may be additional construction costs associated with these building shading and interior configurations. Use of light-colored material throughout the rooms will also diffuse and reflect light, reducing the need for electric light.²⁸

Manual blinds are often lowered to deal with the worst glare conditions and then just get left in that position. Some projects include motorized blinds that either adjust to exterior conditions or rise automatically to a fully open position each morning. Again, the cost of these systems should be considered in light of actual energy savings from reduced electric lighting.²⁹ Daylighting controls add 25 to 50% to the cost of lighting fixtures and are 100 to 200% higher than a basic control system, so care must be taken in planning and design if reasonably rapid payback is expected.³⁰

Going green in the future
Active questioning of traditional and customary laboratory planning assumptions, resulting in "right-sizing" of building systems and appropriate resource expenditures, may be as important a part of sustainable design as any technological application. Laboratories are all about discovering the future, so no one can know exactly what scientists will be demanding in years to come, but we can learn a lesson from science and continue to improve design and construction efficiencies by vigorous investigation.

click to enlarge Fig. 7. Lighting control zones vary the level of electrical illumination, depending on the amount of light coming in the window.

Just like everything else, laboratories are bound to include more digital data-intensive processes in the future, with computer modeling, "labs-on-a-chip," and robotic compound storage and retrieval and cell culture systems. In any case, pursuit of sustainable design will continue to be a responsible reaction to global environmental issues.

There are costs associated with "green" design and construction, but building program variations cause greater differences in cost than those resulting from sustainable design choices.³¹ Cost analysis has an important role in environmentally responsible construction, and contributes to the advancement of architecture and engineering and the conscientious construction of our built environment.

References
1. Gro Harlem Brundtland. "Our Common Future" (World Commission on Environment and Development.) quoted in Sustainability. Australia National Center for Sustainability, undated. www.ncsustainability.com.au/sustainability/. Reference 8/26/2010.
2. U.S. Green Building Council. "LEED-NC for New Construction Reference Guide." Washington, D.C.: U.S. Green Building Council, October 2005. Version 2.2. Page 12.
3. KlingStubbins. Sustainable Design of Research Laboratories. Hoboken, NJ: John Wiley & Sons Inc., 2010. Page 2.
4. Nancy Carlisle. "Introduction to Low-Energy Design." Labs21, July 12, 2010. www.labs21century.gov/toolkit/ledintro.htm. Reference 8/26/2010.
5. KlingStubbins. Sustainable Design of Research Laboratories. Page 13
6. Ibid. Page 2.
7. Ibid. Page 22.
8. Ibid. Page 27.
9. Ibid. Page 30-31.
10. American Institute of Steel Construction. "How is Structural Steel Made?" 2010. www.AISC.org/content.aspx?id=3786. Reference 9/1/2010.
11. Concrete Reinforcing Steel Institute. "Recyclable Materials." 2008. www.CRSI.org/rebar/recycling.cfm. Reference 9/1/2010.
12. American Concrete Paving Institute. "Why recycle Concrete Pavements?" ACPI Technical Series Documents. Kokie, Ill.: ACPA, 2010. Page 1.
13. KlingStubbins. Sustainable Design of Research Laboratories. Pages 48, 54.
14. Ibid. Page 56.
15. Ibid.
16. Ibid. Page 57.
17. Ibid. Page 253, 262.
18. Ibid. Page 194.
19. Ibid. Page 193.
20. Ibid.
21. Ibid. Page 195.
22. Nancy Carlisle. "Introduction to Low-Energy Design." Labs21, July 12, 2010. www.labs21century.gove/toolkit/ledintro.htm. Referenced 8/26/2010.
23. KlingStubbines. Sustainable Design of Research Laboratories. Page 130.
24. Ibid.
25. Ibid. Page 137.
26. Ibid. Page 139-159.
27. Ibid. Page 173-178.
28. Ibid. Page 211-216.
29. Ibid. Page 216-217.
30. Ibid. Page 232.
31. Lisa Fay Matthiessen, Peter Morris. Cost of Green Revisited. Davis Langdon, 2007. Page 3.

Taylor R. Boyd, PE, CCE, is chief estimator; John D. Neilson, AIA, is principal, director of science & technology projects; and Ellen Sisle, AIA, LEED AP, is director of laboratory planning, KlingStubbins, Cambridge, Mass. (www.klingstubbins.com).

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