Allplan BIM Compendium - Theory and Practice. Reseña / by Javier Sánchez-Matamoros Pérez

Durante mi búsqueda de documentación y estudio sobre metodología BIM, he encontrado un interesante documento, producido por la propia Nemetschek Allplan Systems GmbH (que recientemente ha cambiado de nombre y logotipo), en el que se plantean las líneas generales de trabajo con metodología BIM y Allplan: Allplan BIM Compendium. Theory and Practice

Building Information Modeling (BIM) is the integrated approach for the optimized design, planning and execution of buildings. Allplan, as a BIM platform, provides the ideal base with its object-oriented 3D model. Relevant information is entered, compiled, combined, and networked into one intelligent prototype. Architects and structural engineers reap the rewards of harnessing the most up-to-date planning data and can calculate costs even before construction begins. The BIM-Compendium was designed as a reference for Allplan users who create and exchange three-dimensional data with partner offices and or different programs.

El documento, escrito en inglés (algo a lo que hay que acostumbrarse cuando se trata de BIM) y disponible gratuitamente, supone una acercamiento práctico a la metología BIM que, pese a estar centrado en el uso de Allplan, ofrece una visión general útil para cualquier usuario interesado en BIM:

Although BIM and its methods are increasingly used in the building industry, there are still a great many interpretations, doubts and misunderstandings. Today you can find a multitude of documents and publications dealing with BIM. However, these documents usually focus on the theoretical aspects of BIM, generally ignoring office routine.

This BIM compendium is different. It has two parts that are closely related:

  • The first part covers the BIM philosophy in general and its underlying ideas and methods. In addition to discussing myths and doubts, this part also looks at the opportunities and advantages of BIM. Under the motto of "all you need to know about BIM", this part provides you with the theoretical background you need for implementing BIM in your daily work.
  • The second part describes the BIM philosophy in detail, showing you how to use BIM in a real project. You will work your way through the project tasks step by step, learning how and to what extent BIM can be applied to a specific project. Despite the motto of "integrated thinking", this does not necessarily mean that the whole project is geared to the BIM approach. Sometimes it makes sense to use BIM in specific project phases or areas only.

El manual está estructurado en los siguientes capítulos:

  • Introduction.
  • The BIM Process.
  • BIM and Allplan.
  • BIM in practice.
  • FAQs on IFC and BIM.
  • Appendix I - Check Lists.
  • Appendix II - Attributes.

Una visión general de BIM e IFC

El primer capítulo, Introduction, comienza con una definición de términos habitualmente utilizados en entornos BIM (Building structure, IFC, IFCClass, PSet, BaseQuantities...) y que, en mi opinión, todo usuario de BIM debería conocer.

A continuación, se hace una reseña histórica sobre BIM e IFC para acabar, en el capítulo The BIM Process, describiendo las líneas maestras de la metodología BIM:

[...] BIM and its philosophy is much more than just creating a 3D building model with the aid of (CAD) software and attaching information and attributes to the objects and components within this model. Furthermore, BIM is not limited to planning and construction, that is, the work typically done by architects. Rather, BIM encompasses the full life cycle of a building.

Allplan y BIM

La segunda mitad del documento se centra en el flujo de trabajo BIM utilizando Allplan como herramienta de creación del modelo:

Allplan's data structure and its numerous tools and objects are tailored to suit the needs of architects and engineers. Therefore, Allplan provides the ideal platform for creating, editing and maintaining a BIM model as well as handling projects in accordance with the BIM concept.

El esquema de trabajo planteado por los autores comienza, en el apartado Before getting started on the project, con una evaluación del software disponible en el propio despacho de arquitectura y en el de los diferentes colaboradores, de modo que sirva de base para establecer los requisitos de intercambio del modelo BIM, establecer el coordinador del modelo y decidir el repositorio centralizado de la información:

[...] the BIM process should start together with the project. So you have to take decisions and make arrangements on which you can build. Like cooperation and data exchange in general, BIM will only be successful if all those involved communicate openly and easily. As you can see, communication is the essential factor.

A partir de este punto, se van desarrollando a lo largo de los capítulos las diferentes fases de un flujo de trabajo BIM:

  • Creating the model
    • The building structure
    • The plane model
    • Layers in Allplan
    • Working with lines styles and area styles
    • Attributes and properties
  • Elements and attributes
    • Unfinished structure
    • Finish
    • Rooms
    • Attributes of hierarchic levels
  • Export from Allplan
    • Exporting to IFC
    • Exporting to BIM+
  • Checking data
    • IFC viewer
    • BIM+ web explorer
  • Import to Allplan
  • Updating the model
    • Comparing data
    • Modifying data

A lo largo de estos capítulos se tratan todos los temas importantes para conseguir que los modelos BIM generados con Allplan contengan el máximo de información posible y, sobretodo, que sean completamente compatibles con el estándar IFC:

Check these rules time and again, making sure you do not have to spend much time correcting data later:

  • Create all the elements and components of the building model in 3D using the corresponding Allplan tools.
  • Use a BIM-compliant building structure for the data. Make sure the model includes drawing files of the appropriate structural levels only.
  • Define any details and values of the components and objects together with their geometry or use attributes to attach the data to the components and objects.

Apéndices

Si bien la creación de la estructura del edificio y de los elementos constructivos no supone ninguna dificultad más allá del conocimiento de los comandos del programa, el manejo de atributos y propiedades se convierte en el verdadero quid de la cuestión y debe ser tenido muy en cuenta durante la creación del modelo:

[...] Using attributes, you can attach details and values to any object in your drawing. These data can then be analyzed in various ways, transferred to other programs for further editing or displayed on screen, in layouts and in drawings.

[...] Attributes are one of the core aspects of BIM's underlying methods and ideas. BIM does not work without attributes.

Si bien Allplan permite el uso de multitud de atributos (Name, Function, Material, Component ID y user-defined attributes/Allplanattributes); lo realmente importante es utilizar atributos compatibles con IFC:

In an IFC building model that complies with the regulations specified by buildingSmart and IAI, each (architectural) element must have a minimum of specific properties and attributes that are defined in the corresponding property package (PSetCommon). Similarly, the minimum geometric values required are referred to as BaseQuantities. The number of minimum requirements varies from element to element.

In addition, there are the interactions with other components. These are usually superordinate objects, subordinate objects and adjacent objects. These interactions are referred to as relations. Like most geometric values, they are created and calculated automatically. They reflect the hierarchy in Allplan, where you can find PARENT (superordinate) and CHILD (subordinate) elements.

Para facilitar la gestión de los diferentes atributos y garantizar su correcta incorporación al modelo IFC, el manual incorpora en su Appendix II - Attributes una extensa lista con todos los tipos de objetos y los diferentes atributos posibles, relacionando los atributos definidos en IFC con los utilizados en Allplan.

Conclusión

Más allá de conocer el manejo básico de Allplan, considero que este manual debería ser de lectura obligatoria para todo aquel que esté realmente interesado en conocer y aplicar la metodología BIM. De nada sirve conocer en profundidad las herramientas de modelado (Allplan, Revit o ArchiCAD) si no estamos en disposición de integrarnos en un flujo de trabajo BIM centrado en la colaboración a través de estándares abiertos (IFC).