1.2 The CityGML Format and Its Application Domain
Extensions (ADE)
At urban scale, the international open standard CityGML is an XML-based data
model that defines classes and relations for 3D object in cities (e.g. buildings, roads,
water bodies etc.). This format also provides for domain-specific extension to other
objects or attributes using Application Domain Extensions (ADE) [4].
The Energy-ADE extends the CityGML Standard by features and properties
necessary to perform urban energy simulation and to store the corresponding results
[7, 8]. It contains information concerning construction, materials, building occupancy, energy and systems. Moreover, developers of this ADE highlight that “the
Energy ADE is structured modularly in order to potentially reuse and extend some
of its modules in other domains and applications” [8]. In other words, the data
model developed in this ADE can be potentially extended to integrate data required
for urban scale LCA.
To date, no LCA tools or studies were identified that developed a link with
CityGML files to perform urban scale LCI. An important issue related to the
integration of BIM and LCA at urban scale is that LCA data requirements have not
been fully integrated into the CityGML format nor its ADE.
1.3 Aims and Approach
The aim of this paper is to propose ways for extension of CityGML and
Energy-ADE standards in order to exchange information for LCA simulation at
urban scale. The scope of the study is limited to the integration of information
necessary for LCA of buildings’ construction and renovation. First, data requirements are listed and then compared to CityGML and Energy-ADE structures to
identify missing information. Finally, propositions and recommendations are presented to fully integrate information needed for LCA at urban scale into CityGML
and Energy-ADE.
2 Identification of Data Needs for LCA at Urban Scale
2.1 LCA Methodology at Urban Scale
To perform LCA at urban scale, the physical boundaries of the urban project under
study have to be defined. All objects and flows located within these physical
boundaries are identified. This includes in particular the following objects:
A Proposition to Extend CityGML …
283
Extensions (ADE)
At urban scale, the international open standard CityGML is an XML-based data
model that defines classes and relations for 3D object in cities (e.g. buildings, roads,
water bodies etc.). This format also provides for domain-specific extension to other
objects or attributes using Application Domain Extensions (ADE) [4].
The Energy-ADE extends the CityGML Standard by features and properties
necessary to perform urban energy simulation and to store the corresponding results
[7, 8]. It contains information concerning construction, materials, building occupancy, energy and systems. Moreover, developers of this ADE highlight that “the
Energy ADE is structured modularly in order to potentially reuse and extend some
of its modules in other domains and applications” [8]. In other words, the data
model developed in this ADE can be potentially extended to integrate data required
for urban scale LCA.
To date, no LCA tools or studies were identified that developed a link with
CityGML files to perform urban scale LCI. An important issue related to the
integration of BIM and LCA at urban scale is that LCA data requirements have not
been fully integrated into the CityGML format nor its ADE.
1.3 Aims and Approach
The aim of this paper is to propose ways for extension of CityGML and
Energy-ADE standards in order to exchange information for LCA simulation at
urban scale. The scope of the study is limited to the integration of information
necessary for LCA of buildings’ construction and renovation. First, data requirements are listed and then compared to CityGML and Energy-ADE structures to
identify missing information. Finally, propositions and recommendations are presented to fully integrate information needed for LCA at urban scale into CityGML
and Energy-ADE.
2 Identification of Data Needs for LCA at Urban Scale
2.1 LCA Methodology at Urban Scale
To perform LCA at urban scale, the physical boundaries of the urban project under
study have to be defined. All objects and flows located within these physical
boundaries are identified. This includes in particular the following objects:
A Proposition to Extend CityGML …
283