Building Information Modeling (BIM) is an increasingly common acronym among architects. Most offices and professionals are already migrating or planning to switch to this system, which represents digitally the physical and functional characteristics of a building, integrating various information about all components present in a project. Through BIM software it is possible to digitally create one or more accurate virtual models of a building, which provides greater cost control and efficiency in the work. It is also possible to simulate the building, understanding its behavior before the start of construction and supporting the project throughout its phases, including after construction or dismantling and demolition.
BIM methodology is mostly developed for and applied to new construction projects and its potential for renovations and retrofits is still less explored. If we take into account societal needs to improve the spatial quality and poor performance of the vast majority of existing building stock, especially with regards to energy consumption, BIM can contribute to making retrofits and renovations more efficient, intelligent and sustainable.
To achieve better control of the project stages, several governments, companies and owners have been requesting the preparation of projects in BIM, which allows greater detail in budgeting and the planning of preventive maintenance for the project. BIM can be used to predict possible errors in the generation of designs for different project areas, as well as checking the impacts of design decisions and identifying incompatibilities between systems. A project started on a BIM platform has a quite different approach than CAD, as not only its most visible geometry is represented, but all its components and even elements that are not so evident yet can influence design decisions.
Undeniably, working with renovations is always a little riskier than starting a work from scratch. There are pleasant and unpleasant surprises in the process that require quick and accurate resolutions to avoid wasting time and, above all, resources. To reduce the possibility of mishaps, the first step is to invest in research and digital representation of the environment or building. For this, everything from 2D CAD drawings or building document sets is valuable information for creating a building model. Of course, if the building is older, it is very likely that all documents will be on paper, requiring extra scanning and work. There are companies that specialize in surveys, as well as processes that digitally capture the environment using lasers and scanners, through point clouds or photogrammetry, which can even be done using drones.
Once the geometry is captured, the more difficult part of introducing data about installations begins (piping, HVAC, electricity). This is worth the effort, however, since with a well-built model that is true to the building to be remodeled, we have a database that can be used and updated throughout its life cycle, from the work itself to subsequent scheduled maintenance. Most importantly, with a BIM model it is possible to understand and predict how the project will be executed and how it will behave with issues such as thermal, visual, and acoustic comfort, among others. In addition, you can register the model and have greater control over the origins of materials, the processes you went through, and the proper destination in the event of disassembly.
For example, through a BIM model it is possible to simulate the use of natural lighting, shading elements, and even the potential for harnessing photovoltaic energy at a given location. If the model is complete enough to cover both hydraulic and air conditioning installations, it is possible to test and propose specific or radical modifications that can improve system efficiency. Of course, the important thing is to have the possibility to compare previous calculations and determine whether or not the investment will be logical. Designers can quickly estimate actual energy performance by replacing a particular facade cladding for another with a higher insulation level, or simply test another color, for example. Even a quick carbon credit report on the building, auditing all materials and processes for possible later certification, is possible.
In addition, BIM allows for greater cooperation between the various consultants and actors involved in the project, better management of time and workflows, and, above all, assists in the detection of any conflicts and incompatibilities so common in works of renovation and retrofitting. With the huge inventory of existing buildings in our cities, coupled with the latent concerns about natural resource conservation and sustainability, nothing is more natural than focusing on developing smarter, more sustainable and more efficient rehabilitation and reuse projects. BIM can contribute a lot to that.
