Fire Walls Part 1 What do they get me?

Often during the design process the benefits of utilizing a fire wall arise, with “what will this get me?” coming into question.  The use of fire walls as part of a building’s code strategy can allow for the realization of substantial benefits, but users also must be aware of what a fire wall installation will not get them.

A fire wall is a “A fire-resistance-rated wall having protected openings, which restricts the spread of fire and extends continuously from the foundation to or through the roof, with sufficient structural stability under fire conditions to allow collapse of construction on either side without collapse of the wall” (780 CMR 202).

The two main benefits of a fire wall for consideration are:

  1. Height and Area: The height and area of each building separated by a fire wall is evaluated separately. This allows for taller buildings and/or larger footprint areas since the heights and areas of adjacent structure is evaluated between fire walls, as opposed to the aggregate area of abutting structures.
  2. Construction Type: Buildings separated by a fire wall are permitted to consists of different construction types. In other words, on one side a building could be combustible, wood framed construction and on the other side could consist of noncombustible steel construction as long as height and area limitations are not exceeded for each side independently.

Depending on local code amendments, fire walls can also influence factors such as evacuation zoning, fire protection system scoping, etc.

To assure that fire walls provide sufficient protection to prevent fire spread or compromise to the structural integrity of buildings separated, there are a number of requirements that need to be met to assure that these assemblies are constructed to meet this objective. Stay tuned for the next insight as part of this fire wall series outlining how fire walls are constructed.

If you have any questions regarding fire walls on your project, please contact our office at or 617-500-7633.


Application of any information provided, for any use, is at the reader’s risk and without liability to Code Red Consultants. Code Red Consultants does not warrant the accuracy of any information contained in this blog as applicable codes and standards change over time. The application, enforcement and interpretation of codes and standards may vary between Authorities Having Jurisdiction and for this reason, registered design professionals should be consulted to determine the appropriate application of codes and standards to a specific scope of work.