Mapping Scheme Methodology

Analysing the information available in the various census surveys, it was observed that the common relevant features for classifying the building portfolio according to the expected seismic response are: predominant material of the exterior walls, material of the floor, type of dwelling, material of the roof, and type of area (urban or rural). None of the surveys included information regarding the number of storeys, nor the lateral load resisting system; and only the census from Venezuela made reference to the year of construction.

Despite having several features for classifying the building portfolio, the different web applications for downloading census data only allow disaggregation of the number of dwellings in each region by a maximum of three attributes (with the exception of Colombia and Venezuela, where only two attributes can be selected). Therefore, the updated schemes were based on the material of the exterior walls/floor and the type of dwelling, plus the knowledge regarding the typical building classes in the region that have been gained by examining the reports from GED (PAGER and UN-HABITAT), WHE and the building fractions estimated during the GEM workshop in Medellin.

In brief, the mapping schemes consists on two tables: the first table allocates a building category according to the material of the exterior walls and the material of the floor, and the second table assigns building fractions to the possible typologies given the type of dwelling and the building category previously defined. The building typologies have been defined in accordance with the GEM Building Taxonomy (Brzev et al., 2013).

Help us to improve mapping scheme on your country!

You can help to improve the mapping scheme of your country by assigning the proportion of building types in accordance with the wall/floor materials of the dwellings. The following document has a detailed explanation on how to fill-in the corresponding excel spreadsheet. How to improve it?

You can download the spreadsheet for your country, assign the building fractions according to your expertise and then send it by email to

Please note that by sending us this information you grant the GEM Foundation permission to use and distribute it under GEM standard data licensing terms.

  • risk/exposure/mapping.txt
  • Last modified: 2015/09/10 12:29
  • by Catalina Yepes