Critical Ratios

Benchmarking ratios can be an important and useful tool in helping to validate the program information for science facilities. Such ratios include: net/gross efficiency ratio, laboratory density, and construction cost/gross sf. 


Net/gross efficiency ratio:

A project program typically quantifies the required net assignable area before the building is designed and, therefore, before the overall gross area is known. Key factors that can affect the "efficiency" ratio include: 

  • Floor plate size (often impacted by site availability)
  • Circulation scheme
  • Single vs. multi-story design
  • Availability of central campus utilities vs. stand-alone building systems
  • Campus/neighborhood architectural context Laboratory density:

Laboratory Density:

  • This ratio is a measure of laboratory/laboratory support net area as a percentage of the building gross area. 

  • The average among our project sampling is about 40% laboratory net space as a percentage of overall building gross area. This is important because the laboratories tend to be the expensive space in the building. Thus, if your project has a higher or lower laboratory density than this average, you might need to adjust your cost/sf expectations accordingly.
Construction cost/gross sf:

  • Since virtually all clients are interested in construction cost, it is important to be able to use benchmarking data to establish realistic cost targets early in the project, well before the building design is complete. Cost drivers include such items as:

  1. Campus/neighborhood architectural context 

  2. Laboratory density 

  3. Fume hood and laboratory equipment density 

  4. Density of laboratory piped services 

  5. Integration of technology 

  6. Maintainability 

  7. Building controls 

  8. Laboratory casework system

 

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