Circular economy begins in the planning process

The calculation of the material quantities from existing buildings alone poses a large challenge for the building industry. Companies, who have already implemented an openBIM process, have a clear advantage. Users of market-leading, openBIM programs like ELITECAD, have already been calculating the amounts of building materials at the click of a button for years. The basis for the evaluation of the recyclability of a building is intelligent digital building models.

The true value is only first achieved when the digital model is maintained over the entire life-cycle of the building. This begins already at the planning phase but does not end at the "as-built" model but rather includes every renovation, addition and even the demolition. This way the unused and available materials can be easily determined at any given point. ELITECAD has, for years, offered the practical renovation planning function "Time-Machine", where every construction element can be marked with a renovation status. The advantage being that all the information for existing, demolished and new structure elements, including amounts, are available in a single, intelligent BIM model.

One further important aspect of circular building is the specification of the material and construction elements. How, for example, are the walls of a building constructed? How easily are the individual layers separated from one another? What is the carbon footprint of a specific building component and what is its life expectancy? In BIM models, this information is already defined in the planning as building component properties. With this, a prognosis of the longevity of a building can be determined already in the planning phase. ELITECAD offers practical functions for adding attributes to aid in this process. Countless datasets and attributes concerning sustainability criteria are already pre-installed and can be simply assigned to construction elements. By using attribute visualization and attribute stamps, the properties are clearly displayed in both the 3D depiction and the plans.

Conclusion thus far: Those who possess digital twins of their buildings, have a clear advantage. But what about older, long-standing buildings? In the 60's, there were no BIM models let alone CAD plans – how can these now be simply digitized?

The field of architectural surveying has also advanced is recent years. Nowadays, buildings can be surveyed using smartphones and their integrated LIDAR sensors and converted into digital models. ELITECAD contains many practical tools for the processing of point clouds. In only a few steps and by specifying the corner points and heights, an intelligent, dimensioned model can emerge from a point cloud. This can serve as the basis for restoration, renovation or as an information source for the evaluation of recyclability.

In the future once the technical and legal prerequisites have been created by politics and business, so that BIM can be used across the entire value chain, each building should be issued a digital material pass and be registered into a digital resource registry. This will make it possible to offer the recyclable building materials via a material exchange to be able to be reused by construction projects in the area. Based on the life-expectancy information of the buildings and materials, prognoses of future available material availability can be predicted.