Evaluation of BIM-based Building Permit NRW

BIM models are increasingly being applied for planning, execution, and operation of construction projects. The geometric information contained in models regarding building properties and geometries, construction products, and processes can also be used for the digitalization of building planning and regulatory administrative procedures. 

The goal of the former research project „BIM-based Building Permit“ was to achieve such a digitized handling of the entire building permit process (planning, application submission, application review, approval). This project was conducted in cooperation with numerous stakeholders from authorities, research, and industry and was funded by the State of NRW. Requirements for BIM models regarding information content were formulated to match the information level of today’s building application documents and to enable the extraction of information within the proejct-specific use cases. During the project, a modeling guideline (MRL) for BIM-based building permit procedures was developed based on the Landesbauordnung (LBO) NRW. Additionally, validation rules were defined to algorithmically implement the technical requirements of the LBO NRW. The rules focus on checking the building class, defining rooms, usage units, and calculating gross floor area (BGF) as well as net room area (NRF). Another focus was on fire protection requirements for the approval process. Finally, a prototype software implementation was carried out to: 

• Validate the conformity of the building model with the standards and guidelines described in the MRL (Formal Validation) 
• Model validation regarding the previously defined focal points (Technical Validation)

In the following research project “Evaluation of BIM-based Building Permits” the application of the gained insights regarding model requirements, digital communication, technical and organizational prerequisites will be evaluated. The evaluation is based on eight building projects in the cities of Bochum, Dortmund, Düsseldorf, Essen, Herne, Cologne (two projects), and Münster with the involvement of the respective building supervisory authorities.

The projects differ in terms of their project type (new construction, extension, renovation) and the type of building permit review: 

• BIM-based building permit review parallel to the conventional review
• BIM-based building permit review before the conventional review
• BIM-based building permit review following the conventional review 
• Purely BIM-based building permit review

The defined focal points of the review in the project will be evaluated regarding: 

• Correctness of the modeling guideline
• Completeness of the modeling guideline
• Understandability of the modeling guideline
• Applicability of the modeling guideline 
• Effort required to use the modeling guideline

Based on the feedback of the project, the modeling guideline will be iteratively expanded. Finally, the experiences of the planners and reviewers will be captured in a digital questionnaire with concrete examples for a subsequent evaluation.