United States
 Environmental Protection

 Research and Development
 Air and Energy Engineering
 Research Laboratory
 Research Triangle Park, NC 27711
 EPA/600/SR-93/218   January 1994
 Project  Summary
 Characteristics  of  School
 Buildings  in  the  U.S.
 Harry Chmelynski
   A subsample  of  100  schools  from
 the Environmental Protection Agency's
 (EPA's) National School  Radon Survey
 were visited to obtain information on
 building structure,  location of utility
 lines, and the type of heating, ventilat-
 ing, and air-conditioning (HVAC) sys-
 tem. Information from each school was
 entered into a database to determine
 the  relative proportions of physical
 characteristics of the U.S. school build-
 ing  population.  Results indicate that
 most school structures are of slab-on-
 grade  construction, gravel  was used
 as subslab fill material in  approximately
 50% of the structures, approximately
 80% of the schools have either central
 HVAC or unit ventilators capable of de-
 livering conditioned outdoor air to the
 classrooms, and almost 25% of the
 schools have subslab footings extend-
 ing both beneath the classroom walls
 and  along the corridors, thus compli-
 cating the installation of  effective sub-
 slab depressurization systems. The re-
 sults obtained in this study will be used
 by the EPA to guide future mitigation
 research in schools.
   This Project Summary was developed
 by EPA's Air and Energy Engineering
 Research  Laboratory, Research Tri-
 angle Park, NC, to announce key find-
 ings of the research project that is fully
 documented in a separate report of the
 same title (see Project Report ordering
 information at back).

  To help guide future radon research in
schools and to better focus  technical guid-
ance documents, the Air and Energy En-
 gineering Research Laboratory (AEERL)
 of EPA's Office of Research and Develop-
 ment conducted a literature search to find
 information that  quantifies the physical
 characteristics  of U.S.  school buildings.
 Information specific to radon mitigation re-
 search in schools was  not found  in any
 existing reports or databases. As a result,
 AEERL's Radon Mitigation Branch  (RMB)
 chose  to characterize  the  U.S.  school
 building population using a sample  of 100
 schools from the  National School  Radon
 Survey  (NSRS). The schools are a na-
 tionally  representative  random sample
 selected by EPA's Office of Radiation and
 Indoor Air.
  The 100 schools were visited to  obtain
 information on building structure, location
 of utility lines,  and the type  of heating,
 ventilating, and air-conditioning (HVAC)
 system. Information for  each  school was
 entered  into a database to determine the
 relative proportions of physical character-
 istics of the U.S.  school building popula-
 tion. To record the necessary information,
 a building characteristic  profile sheet was
 completed for each school  by RMB staff
 engineers and selected contractors  during
 1991 and 1992.
  The three-page  profile sheet was  devel-
 oped for this project for on-site character-
 ization of the structure, utility penetrations,
 types of HVAC equipment, and other build-
 ing features pertinent to radon  diagnostics
 and mitigation. Because many schools
 have several contiguous structures often
 constructed  at different  times  and each
 with its  own unique characteristics,  the
 profile sheet was completed  separately
for each structure. In a few cases, where
the structures are  not contiguous but are
                                                    Printed on Recycled Paper

campus-style complexes, profile sheets
were completed for each distinct structure
in the school, unless all were of the same
vintage and construction type.
   Where available, building plans were
examined  to  determine  structure  and
HVAC system information that is not al-
ways available through on-site observa-
tion. Following inspection of the building
plans, the school was visited to verify in-
formation on the plans and to  collect any
additional profile sheet information that was
not on the plans.  Complete sets of con-
struction plans were available for only 40%
of the structures.  When plans were  not
available, the profile sheet was completed
based on discussions with school person-
nel and the judgement of the researchers.
  The results of the survey provide many
significant findings concerning the distri-
bution of  school building characteristics.
The profile sheets provide evidence of the
variety of building structures  and HVAC
equipment found in  typical  schools. The
age of a school, number  and  size of dif-
ferent structures, type of substructure, lo-
cation of utility lines, and types of HVAC
equipment vary  widely  in  the sample

Major Findings
  Major findings of this study relative to
radon diagnostics and mitigation are:
   Over  70% of school structures have
    slab-on grade construction;
   Gravel was used as subslab fill mate-
    rial in approximately 45% of the struc-
    tures  with information available;
   Approximately 40% of schools have
    a single type of HVAC  system in all
   Approximately  80%  of the schools
    have  either central HVAC or unit ven-
    tilators capable of delivering  condi-
    tioned outdoor air to the  classroom;
   While over 50% of the structures have
    no internal subslab footings (thus fa-
    cilitating  mitigation with subslab  de-
    pressurization systems), almost 25%
    of the structures have footings both
    along corridor walls  and  between
    classrooms (thus complicating the in-
    stallation of subslab depressurization
  The distribution of the profile sheet re-
sponses into the categories used for data
analysis required  reducing detailed  re-
sponses to shorter, categorical responses
for  many  of the profile sheet questions.
The original  responses for each school
were  entered into a  dBase IV file, and a
separate file was created containing the
shorter categorical responses used for the
statistical analyses.
  The full report discusses the  random
sample selection procedures, describes the
information collected on the building char-
acteristic profile sheets, summarizes  some
of the results recorded on  the school pro-
file  sheets, compares the results with those
observed  in RMB's  research schools, de-
scribes  the accompanying dBase IV data
files,  and presents  the statistical limita-
tions  of this study.  The information col-
lected during this study may be  useful to
EPA  and others to guide  future  radon
mitigation research in schools.
                                                                         &U.S. GOVERNMENT PRINTING OFFICE: I9M  S94MM7/MM7


Harry Chmelynski is with S. Cohen and Associates, Inc., McLean, VA 22101.
Kelly W. Leovic is the EPA Project Officer (see below).
The complete report, entitled "Characteristics of School Buildings in the U.S.,"
  (Order No. PB94-121704; Cost: $19.50; subject to change) will be a vailable only
       National Technical Information Service
       5285 Port Royal Road
       Springfield, VA 22161
        Telephone: 703-487-4350
The EPA Project Officer can be contacted at:
       Air and Energy Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Research Triangle Park, NC 27711
 United States
 Environmental Protection Agency
 Center for Environmental Research Information
 Cincinnati, OH 45268

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