A Building Information Model is a digital representation of physical and functional characteristics of a building. BIMs
represent the geometrical characteristics of the Building, but also properties like bills of quantities, definition of COTS
components, status of material in the different stages of the project, project economic data, etc.
The BIM methodology, which is well established in the Architecture Engineering and Construction (AEC) domain for
conventional buildings, has been brought one step forward in its application for Astronomical/Scientific facilities. In
these facilities steel/concrete structures have high dynamic and seismic requirements, M&E installations are complex
and there is a large amount of special equipment and mechanisms involved as a fundamental part of the facility. The
detail design definition is typically implemented by different design teams in specialized design software packages. In
order to allow the coordinated work of different engineering teams, the overall model, and its associated engineering
database, is progressively integrated using a coordination and roaming software which can be used before starting
construction phase for checking interferences, planning the construction sequence, studying maintenance operation,
reporting to the project office, etc.
This integrated design & construction approach will allow to efficiently plan construction sequence (4D). This is a
powerful tool to study and analyze in detail alternative construction sequences and ideally coordinate the work of
different construction teams.
In addition engineering, construction and operational database can be linked to the virtual model (6D), what gives to the
end users a invaluable tool for the lifecycle management, as all the facility information can be easily accessed, added or
This paper presents the BIM methodology as implemented by IDOM with the E-ELT and ATST Enclosures as