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NIST Outdoor Structure Separation Experiments (NOSSE): Preliminary Test Plan



Alexander Maranghides, Shonali Nazare, Eric Link, Matthew Bundy, Artur A. Chernovsky, Erik L. Johnsson, Kathryn Butler, Steven Hawks, Frank Bigelow, William (Ruddy) Mell, Anthony Bova, Derek McNamara, Tom MIlac, Daniel Gorham, Faraz Hedayati, Bob Raymer, Frank Frievalt, William Walton


The Structure Separation Project is a multi-level project to assess structure-to-structure fire spread in Wildland-Urban Interface (WUI) communities. The project is divided into three phases with each phase assessing radiant and convective heat exposures from different sizes of source terms. Phase 1 is considering sheds from 1.39 m2 to 24.8 m2 (15 ft2 to 267 ft2) as source terms while Phase 2 and Phase 3 will study heat exposures from auxiliary dwelling units [40.9 m² (440 ft2)] and single-family homes 92.90 m² (1000 ft2), respectively. This experimental series is an extension of the indoor shed burn experiments performed to measure heat release rates and mass loss rates at the National Fire Research Laboratory (NFRL). These outdoor full-scale shed burn experiments will be conducted in the presence of an artificially generated wind field. Varying sizes of structures containing wood cribs (source of fire) will be used to generate typical radiative and convective heat exposures on a target structure (assembly of an exterior wall with a window and a roof to represent a single-story residential building). The spacing between the source and target structure will be varied to identify safe structure separation distance SSD (SSD) which is defined as the shortest distance between the source and the target structure. The safe SSD for combustible (wood) and non-combustible (steel) sheds will be identified.
Technical Note (NIST TN) - 2199
Report Number


Structure separation distance, wildland fire, wildland-urban interface, wind driven fires, sheds, fire heat flux, fire radiation, fire convection, structure-to-structure fire spread, community fire spread.


Maranghides, A. , Nazare, S. , Link, E. , Bundy, M. , Chernovsky, A. , Johnsson, E. , Butler, K. , Hawks, S. , Bigelow, F. , Mell, W. , Bova, A. , McNamara, D. , Milac, T. , Gorham, D. , Hedayati, F. , Raymer, B. , Frievalt, F. and Walton, W. (2022), NIST Outdoor Structure Separation Experiments (NOSSE): Preliminary Test Plan, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed June 17, 2024)


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Created January 10, 2022, Updated November 29, 2022