Research Project: Life cycle assessment and BIM in sustainable building

Project briefing

• Status Completed
• Project duration February 2019 – December 2019
• Programme Future Building

The coalition agreement of the Federal Government provides for the increased use of the Building Information Modeling (BIM) method in federal building construction with regard to digitization. The strategic orientation of the Federal Office for Building and Regional Planning (BBR) and the Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR) provides for modular implementation and integration of BIM use cases (i.e., interference check). These will be successively developed in close cooperation between the operational construction and research sectors and validated in the federal government's BIM pilot projects. Sustainability is also a high priority for the federal government. Therefore, taking into account the establishment and testing of sustainability certification according to BNB and the already mandatory application, an implementation taking into account the BIM method is the logical consequence.

Project duration: February 2019 – December 2019

Background

BIM is a holistic and collaborative working method that enables the digitization of the entire structure from "cradle to grave" and serves a wide range of stakeholders' perspectives for planning, analysis, construction, operation and optimization. The depth of information of digital buildings grows through the integration of project-specific data. Many software manufacturers have brought proprietary BIM systems onto the market, but due to a lack of interoperability, they are not the universal solution for all user groups.

Since 1995, the buildingSMART organization has been developing the manufacturer-independent open source data format Industry Foundation Classes (IFC), which has the potential to become the standard for many individual solutions. This interoperable data format offers interfaces beyond software boundaries that allow the exchange of different disciplines on the basis of a digital BIM model.

The IFC data format has a flexible structure so that the data sets can be expanded in a structured manner. On the basis of these IFC extension schemas, the data model, objects or properties can be assigned to information sources and linked to each other. Up to now, the extensions have addressed material data (e.g., thermal conductivity) and business aspects (time and cost planning). They are also suitable for mapping more complex relationships (i.e., environmental).

Certification systems, such as the Sustainable Building Assessment System (BNB), play a major role in the environmental assessment of buildings today. A life cycle assessment (LCA) serves as the basic calculation method for an environmental analysis. The environmental impacts of buildings are to be determined on the basis of verified data, which the Federal Ministry of the Interior, for Building and Homeland Affairs (BMI) provides free of charge and quality-tested via ÖKOBAUDAT. Currently, carrying out an LCA is quite complex and time-consuming. Energy and material flows have to be taken manually from 2D drawings and building descriptions. In particular, the technical building services equipment is usually only simplified and shown as a whole in the context of LCA due to the high expenditure of a detailed consideration. Thus, the optimization potential of a whole building LCA as an early and iterative planning instrument has not been exploited to its fullest.

The BIM method and the IFC data format offer great potential for making the preparation of whole building LCA much more efficient. By making the information required for the calculation available earlier, more structured and more easily accessible, an almost fully automated whole building LCA would be possible according to BNB. An essential part of this is LCA data, which should be available within the digital building models.

Objective

Within the framework of this research project, the necessary technical, organizational and contractual prerequisites and basics for the implementation of the whole building LCA based on ÖKOBAUDAT as a BIM use case for future BIM pilot projects were created based on the Open BIM standard of the IFC data model.

The investigations were strongly oriented towards the actual situation when preparing a whole building LCA within the framework of the BNB certificate. This means that the whole building LCA was considered as a basis in late project phases, when all necessary information on material level is available to link specific data sets of ÖKOBAUDAT.

The aim was to define a suitable connection option under the given technical conditions, which allows a transfer of environmental information from ÖKOBAUDAT to the IFC data model. Within the organizational requirements, where it was necessary to define the processes with all information exchange requirements, the processes in late project phases were also considered. Within the scope of the contractual requirements, the work results were prepared in such a way that they can be integrated as text modules into contract bases.

Contractor of the research project was the Technische Hochschule Köln in cooperation with TMM GROUP GESAMTPLANUNGS GMBH and the Bergische Universität Wuppertal.