With a single corridor, the building net-to-gross ratio is usually 60 percent or greater. One corridor provides better opportunities for communication by creating a "main street." The disadvantage is that a single-corridor approach may not meet program needs for the labs and offices or building operations.
Usually, a single corridor limits the width of the building, in turn limiting floor-plan design. Some labs may need to be interior, without any natural light, which may be difficult to achieve with the single-corridor design.
Option IA places labs and offices adjacent to each other. The researcher has access from his or her office directly into the lab. The office is also directly off the corridor to allow easy exiting in case of emergency. The offices will not have direct views to the exterior unless the walls between the lab and office have glazing. To get into the main lab, it will be necessary to enter through the office or lab support area.
Option IB has labs on one wing with offices at the end or in the middle. The office-cluster arrangement creates a sense of neighborhood, encouraging researchers to talk with one another on a daily basis. The offices are located within a short walk of the generic labs, which have internal doors connecting each to adjacent labs. The easy accessibility from one lab to another provides another opportunity for researchers to talk and work together. This is a typical single-corridor scheme.
With Option 1C, teams of researchers are organized in office clusters that can open directly into labs and exit corridors. Interior glazing allows researchers to oversee their lab spaces from their offices. Locating offices directly next to and immediately accessible to the labs is preferred by most researchers but is more costly than locating the offices in a central area.
Two-corridor ("racetrack") arrangements are usually developed to create larger, wider floor plans than are possible with the single-corridor approach. More lab buildings are constructed with two-corridors than with one.
There are several advantages. The building has a wider floor plan. Two corridors allow for labs to be designed back-to-back. There are many layout options. Labs can be located on the interior or exterior.
The building can also allow for "ghost corridors," which permit a person to walk from one lab to another without having to go out into a separate corridor. The ghost corridor is a walkway area through each lab that connects with a door allowing movement from one lab to another.
Ghost corridors, which are used as a second means of egress, are more common in large open labs or in labs where security is not so much of a concern because the researchers know one another. Ghost corridors improve a building's efficiency and cost-effectiveness, and a ghost corridor usually means that a second, separate public corridor will not be necessary.
One disadvantage of a two-corridor arrangement is that this plan separates people by creating a building with "two sides." Furthermore, this concept is approximately five percent less efficient (more costly) than a single-corridor arrangement.
A disadvantage of the ghost corridor design is that it allows a person to walk through the lab to get to another part of the building. This can be efficient and cost-effective if the end users can work with others coming through their lab spaces. Security may, however, be a concern to some researchers.
Options for Two-Corridor Schemes
Option 2A places offices on the outside and labs at the interior. Researchers can be located in office clusters across from their labs and have views to the exterior. The labs are internal, with wall space that can be used for storage or interior glazing. The corridor along the outside wall provides views and natural light for everyone. With this concept, the main labs and support labs can easily be reconfigured as one large lab area.
With Option 2B, labs and offices are on the outside, with lab support on the interior. The main labs and offices have views to the exterior, but the offices are separated somewhat from main labs by the centrally located support labs. The lab support area will work well for research that cannot have natural light coming into the space.
Option 2C has office clusters adjacent to main labs along the outside walls, with the lab support located on the interior. This concept is very functional and is desired by many researchers, but cost may be a problem. The operations of most research teams should work well with this design. The entire building will have to be designed for laboratory construction, which is the most costly approach.
With Option 2D, offices cluster along one outside wall, main labs along the other outside wall, and some main labs with lab support located in the interior. This approach is similar to Option 2B except that the building is wider to allow for the typical main labs to be in the center and to locate the offices in clusters.
A wider building is more efficient because there is more net usable space with the same corridor arrangement. This option is more cost-effective than 2C, because all the offices are located on one side of the building. The mechanical systems can be designed for lab and office construction, which is more cost-effective.
And finally, Option 2E shows offices at one end of the building, with labs located in a "lab wing." This arrangement is similar to Option 2D. In both cases, the separation of office and lab space allows the office space to be constructed as office construction, saving money on the project.
Despite its cost-effectiveness, however, this approach has two disadvantages: some researchers may not be satisfied if labs and offices are not adjacent, and the office space will be expensive to renovate as wet lab space if desired in the future.
Once the basic configuration has been determined, there are other adjacency choices regarding open versus closed plans, space allocated to write-up areas, and a wide range of other general and project-specific issues.
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Daniel D. Watch, AIA, is an architect and laboratory planner with Perkins & Will. He has coordinated the design of nearly 20 major research laboratory facilities.
This article is excerpted from Building Type Basics for Research Laboratories, copyright © 2001, available from John Wiley & Sons and at Amazon.com.