# BIM-Based Method for the Verification of Building Code Compliance
## 1 Introduction  
Building design and construction processes are usually oriented by several regulations and guidelines. The requirements for those regulations are constantly evolving and include a set of data that must be analysed to verify construction compliance. Automated design review or automated code checking is a process or system that evaluates the design based on its objects, attributes and relationships without modifying the design itself [1]. The topic has been addressed since the 1960s, following the introduction of mandatory regulations in the building industry and is becoming increasingly important with the emergence of BIM [2, 3]. Without system automation, compliance checking is usually manually conducted by designers and local authorities, which is still the case in many locations. As the complexity of the designs increases [2], as well as the number of complex building codes for distinct types of constructions [4], manual compliance analyses are very time-consuming and require a deep knowledge of the building, often leading to many assessing and/or calculation errors [5, 6]. BIM can be defined as _\"a digital representation of a building, an object-oriented 3D model or repository of project information to facilitate interoperability and exchange of information withrelated software applications_\" [6]. Moreover, BIM is a working methodology that allows managing all the project design and data in a virtual environment during the project life cycle [7]. It creates the opportunity to virtually construct and simulate the building performance before the construction itself [8]. Some of the main benefits include constant communication among stakeholders, early detection of errors and incompatibilities, supporting decision-making and optimising costs and time [9; 10; 11; 12]. Inherent to this methodology is the development and characterisation of a virtual model--the BIM model--which is created with object-oriented parametric modelling and is characterised by the level of development (LOD). The LOD ranges from 100 to 500 and it describes the model content and reliability [2]. With the emergence of BIM, novel approaches have been developed for automated code checking, creating better and more comprehensive procedures. Usually, automated code checking follows 4 different tasks [13]:  
1. Rule interpretation--Interpretation of the requirements and translation to computer-processable rules. 2. Building model preparation--Creation and characterisation of a digital BIM model. 3. Rule execution--Execution of the established rules, usually using text format coding (Python or C#) or visual programming language (VPL) through Dynamo or Grasshopper. 4. Rule check report--Final result with building evaluation. Following the successful results from this approach [14; 15], this procedure was also adopted to conduct this research. For rule encoding, VPL was used through Dynamo software, as it is more transparent and easier to understand, especially for architecture engineering and construction stakeholders, which usually have limited knowledge of information technologies. LegislationUsually, buildings must comply with several rules defined in the local urban master plans, local construction codes and/or accessibility standards, depending on the building type, use and location. Such rules, exemplified in Figure 1 for the Brazilian case [16], are later analysed and verified by city halls, which certifies whether the building can be built in that location, with its specified characteristics and with the purpose it was designed for. If not, local authorities are demanded to send back the project, requiring the fulfilment of all local regulations. Figure 1: Brazilian legislation. In Brazil, the urban master plan is the basic instrument for the urban development and expansion policy. It comprises a set of guiding principles and rules for architects and engineers to plan quality and comfortable construction for citizens.