Screen Shot 2014-03-17 at 1.48.42 PMSpace Assessment

The concept of space assessment first appeared in Timothy D.  Crowe’s Crime Prevention Through Environmental Design textbook in 1991.  Space assessment is a simple, yet invaluable “guide” for determining what to do with human space and, when dealing with a built environment, assessing how well a space is designed and used.  The guide, referred by Crowe as the “Three-D” concept, is based upon three suppositions.  They are:

  • all human space has some DESIGNATED purpose.
  • · all human space has social, cultural, legal or physical DEFINITIONS that prescribe the desired and acceptable behaviours.
  • all human space is DESIGNED to support and control the desired behaviour.

Each supposition is supported by a series of questions. They are:


  • What is the designated purpose of this space?
  • What was it originally intended to be used for?
  • How well does the space support its current use?  Its intended use?
  • Is there conflict?


  • How is the space defined?
  • Is it clear who owns it?
  • Where are its borders?
  • Are there social or cultural definitions that affect how that space is used?
  • Are the legal or administrative rules clearly set out and reinforced in policy?
  • Are there signs?
  • Is there conflict or confusion between the designated purpose and definition?


  • How well does the physical design support the intended function?
  • How well does the physical design support the definition of the desired or accepted behaviours?
  • Does the physical design conflict with or impede the productive use of the space or the proper functioning of the intended human activity?
  • Is there confusion or conflict in the manner in which the physical design is intended to control behaviour?

The questions raised by this guide can help CPTED practitioners answer the questions “What are you trying to do?” and “how can we do it better?”  It will also help us to achieve the CPTED emphasis by assisting various disciplines do a better job of achieving their primary objective and, through this process, reduce the exposure to crime and loss.