BIM, short for building information modelling, adds database-like information to a 3D CAD model's spatial representation. Elements like walls, windows, floors are defined parametrically, enabling automatic generation of 2D plans, sections and elevations. BIM models can also incorporate non-structural elements, such as MEP installations. Native BIM models in Revit (from AutoDesk) and AECOSim (from Bentley Systems) can be created, and deciding the level of detail is essential. 3D laser scanning is an integral part of the BIM process, especially for the redevelopment of existing buildings. A scan-to-BIM model creates the data foundation for the design.At 3D Engineering, we have extensive expertise in collecting and processing precise point cloud data.

We can create 3D parametric models directly from the point cloud, usually in Revit format, although we can provide models in Bentley AECOsim if required.Using the model, we can generate 2D sheets at any specified location for plans, sections, or elevations. However, it should be noted that these sheets may not contain the same level of information as a typical 2D survey. If specified at the outset, we can manually enhance this information if needed.When dealing with survey data, specifications are crucial, especially in the BIM environment where an almost infinite number of variables are available. We collaborate with our clients to establish specifications from the outset, and it may be necessary to consult with key stakeholders in the project before finalizing the specifications.

LOD (Level of Detail): Determine the necessary level of detail for the model based on the building's intended use. For example, a high level of detail may be needed for a preserved facade, but low detail may suffice for internal partitions if the goal is only to measure the volume to be removed.LOI (Level of Information): Decide how much information you require from the modeled elements. Keep in mind that surveyors may face limitations when accessing certain parts of existing structures and may not possess in-depth knowledge of all related disciplines. Discuss any potential constraints from the outset.

IT'S important to consider the following:● Coordinate system: Decide which coordinate system to use, protect it on site, and make sure all stakeholders are aware of it.● Basepoint of the model: Choose a location and ensure all stakeholders are aware of it to make a federation of models from various disciplines much easier. BIM is a collaborative process, and starting on firm foundations is key to gaining maximum time and cost savings.