On the most basic level, bench types can be classified based on how they are used.  If most of the work at a bench is done with the technician in a sitting position, then one would specify a sitting-height bench, otherwise known as a desk, with an average height to the top of the working surface of 30" above finished floor.  Examples of activities which would occur at a 30" high bench include: writing, reading, and manipulation of small-scale testing procedures and small-scale equipment, procedures which can all be done sitting in one location without having to get up.  If most of the work is done in a standing position, then one should specify a standing-height bench, sometimes referred to as a counter, with an average height to the top of the working surface of 36" above finished floor.  Examples of activities which would occur at a 36" high bench include manipulation of several small-scale procedures over a large area of manipulation of large-scale equipment such that the technician must move across a larger area than would be practical to do in a sitting position.  Another example of this classification of activity would be an "en-route" pick-up or drop-off of a product or sample, where sitting down would be a waste of time.  Typically, in a clinical lab, one provides chairs at 30" high bench locations, and stools at 36" height bench locations.

Along with sitting height vs. standing height, the other very basic classification of bench types revolves around the bench location within the laboratory.  Benches which line the perimeter of a room, and butt up against a wall are sometimes referred to as wall benches.  Because the bench is up against a wall, access is basically from one side.  Benches located within the middle of the lab, on the other hand, allow access from both sides, and are referred to as peninsula benches if one of the short ends is pushed up against a wall, or island benches if one can circulate freely around the bench.  The decision on whether to use wall, peninsula or island benches is usually circumscribed by available room sizes and the need to accommodate all of the lab's requirements and to maximize use of space.

 1.14     Armed now with these two basic classifications (sitting vs. standing height, wall vs. peninsula or island), one can focus on two additional, basic, dimensional guidelines for the design of the bench, i.e., depth and length.  Depth of a bench varies from 12" to 66".  The standard depth, where there are no countervailing programmatic requirements, is 30" at wall benches, and 66” at island or peninsula benches.  The depth of a wall bench is sometimes increased to 36" for a particular programmatic requirement (such as a 32" piece of equipment), and is sometimes decreased below 30" when there is a space shortage; however, decreasing the depth of a wall bench below 30" is often a false economy and ill-advised as there is a sharp fall-off of functionality for many lab functions when the bench depth falls below 30".  The ideal length of a bench varies according to a number of factors, including: height (sitting vs. standing); usage (clear work area vs. equipment storage area); and available space. In general, a desk that is adjacent to or contiguous to a counter is 48" long, but this is sometimes increased to 60" or decreased to 42".  In terms of counters, it is important to allow for sufficient linear footage (or length) of counter to allow for all counter-top equipment (including required clearances between equipment items) as well as sufficient length of counter to accommodate the number of technicians programmed for the space.  As a rule of thumb, we allow a minimum of 72" of clear counter per technician, in addition to the counter space allocated for equipment.

Necessarily correlated with the type and amount of desk and counter area is the type and amount of storage located below and above the work surface.  Beginning with below-counter storage, the client can choose between open shelving and enclosed cabinetry.  Enclosed cabinetry entails either cabinets with doors (hinged or sliding) or drawers, and can be specified as built-in cabinetry (less expensive, less flexible) or on what is referred to as a "C-frame" (more expensive, more flexible).  In general, enclosed cabinetry is preferable from a visual and maintenance perspective, but open shelving might be selected if there was an unusual storage need or a strict budget (as enclosed cabinetry is more expensive than open shelving).  Moving onto above-counter storage, one encounters the same options of shelving (wall-mounted) or enclosed cabinetry (again, wall-mounted).  In general, the norm for below-counter storage is enclosed cabinetry, while above-counter storage is usually split between shelving and enclosed cabinetry, with budget usually swaying the mix in one direction or another.  (Please note that storage of chemicals, flammables and nuclear materials is a subject of considerable complexity, and beyond the scope of this article.)

An important consideration in laboratory bench design is the provision of plumbing and electrical services within the bench.  By plumbing, one must account for sinks (full size and/or cupsinks) and hand-held eyewashes, as well as laboratory gasses, which can include "air", "gas", and/or "vacuum".  This accommodation must include the routing of piping, as well as the accommodation on the benchtop itself of the sink and gas spigots.  Equally important is the provision of electrical service to accommodate the wide range of laboratory equipment required.  Once the collective electrical load has been calculated, it must be allocated and distributed to the appropriate equipment and workstation locations.  This distribution is either hidden in a wall or bench chaise, or surface-mounted in wiremold.  The wiremold itself comes in many varieties, including a double-chambered version which allows for the distribution of power in one chamber, and telephone/data in the other chamber.  Electrical and telephone/data locations are then located at a certain spacing (usually 18" to 24" on center) either as outlets in the wall or outlets in the wiremold.

A final parameter of laboratory bench design is the selection of materials.  Most important is the desk of benchtop material itself. The two most typical options here are the ubiquitous but incredibly durable epoxy resin (which can be downgraded for budget reasons to one of the numerous epoxy resin knock-offs), stainless steel, or plastic laminate (which can be upgraded, if the budget allows, to chemical-resistant laminate).  Epoxy resin is a superb surfacing material for all locations, but it is substantially more expensive than plastic laminate, and therefore can be used at a minimum in wet locations of sinks and cupsinks.  Stainless steel is used for benchtops in very specialized circumstances of extreme corrosiveness, extreme moisture, or a requirement for extreme cleanliness.  Chemical-resistant plastic laminate is recommended for desk locations, and is becoming more and more common as a benchtop surface due to increased budgetary restrictions on laboratory construction.  The drawbacks to plastic laminate as a benchtop material, however, is limited chemical resistance (even for the chemical-resistant variety) and a tendency to delaminate, especially if used in wet areas.

The considerations underlying the selection of benchtop materials tends to also apply to the selection of the materials for above-counter and below-counter storage.  Looking at the two extremes of low tech/low cost and high tech/high cost, at the low end of the spectrum where plastic laminate is maximized as a countertop material, one would expect to see wide-spread use of plastic laminate shelving above- and below-counter, and plastic laminate or painted steel cabinets if cabinets are utilized at all.  At the high end of the spectrum, where one finds stainless steel countertops, one would also expect to find stainless steel shelving and/or cabinets above- and below-counter.  Most laboratories, however, fall  between these two extremes, utilizing metal cabinets below the counter with a mixture of metal cabinets and open shelving above the counter.  Metal cabinets are preferred over

plastic laminate cabinets due to the aforementioned tendency of plastic laminate to delaminate not only in wet areas but also in areas of high usage/impact, such as drawer and door fronts.  A final cabinet material system which should be mentioned is a modular, high-density, plastic cabinet system which is fabricated by furniture manufacturers.  While promising modularity and flexibility, a drawback of this material system is that it does not hold up as well over time as the plastic laminate or steel cabinet systems described above.

 In summary, the design of the laboratory bench (as a mirror of the laboratory as a whole) must strike a balance between functional and budgetary concerns, as the design team sorts through detailed design parameters including: type (desk vs. counter), location (wall vs. island or peninsula), dimensions (length and depth), provision of engineering services (plumbing and electrical), and, finally, material considerations.