There is a large inventory of existing buildings in the U.S. that are in various states of repair and disrepair. Renovation versus building new makes a lot of sense economically and socially. Read how to develop existing-conditions BIM model for a renovation without a trace.
The use of Building Information Modeling (BIM) for renovation projects can bring in huge benefits in terms of time and cost saving. Despite many advances in technology, designers, contractors and engineers are still tracing over the paper documents of our predecessors while making a plan for renovation.
The design workflow for a renovation starts with some sort of accounting for all of the existing conditions that will be affected by the project. The architect procures as many of the old design documents or paper sheets as he or she can. There is a bigger chance that the paper sheet set may be incomplete, or not reflective of all renovations and changes made to the building since its initial construction. So, the architect performs field-measurements to fill in the missing information, and to check the as-built conditions versus the design documents.
Before the new design proposals can be done, the architect has to engage in tracing over the existing drawings. Once the existing drawings are traced and reconciled with the field measurements, only then the architect can proceed with the new design proposals.
This process takes a considerable amount of time. When you add BIM, it becomes even more time-consuming. How do we transform an existing building in all its glory into a 3D digital model suitable for BIM purposes? The article describes two methods you can use to start the design of your renovation project 'without a trace'. They are:
A. 3D Laser Scanning
B. Laser Distance Measures
A. 3D Laser Scanning
This method is comprised of a couple of steps:
- A 3D laser scanner is used to scan the exterior and interior of a building.
- The laser scanner captures individual data points that when viewed in a single file are a highly accurate model of the building, both dimensionally and visually.
- The laser scanner generates a point cloud file which you import into a CAD program.
- Using the point cloud file as a guide, you then create a 3D CAD model using the 3D modeling software of your choice, such as Revit or ArchiCAD.
3D laser scanning offers several advantages. The point clouds can be very detailed, and can capture very intricate detail within a few millimeters of accuracy. The laser scanner automatically captures adjacent site conditions when it is used to capture exterior conditions of the building.
With the laser scanner method, you still have to manually create a BIM model using the point cloud as a guide. The upside is that the point cloud is in 3D and accurately reflects the actual construction. You can detect walls or floors that are out of square. There are some software tools that can transform some of the point cloud data into a partial BIM model, such as PointCloud from Kubit.
B. Laser Distance Measures
With this method, you field-measure the building using a hand-held laser distance measure. Measurements are transmitted wirelessly from the measure to a laptop running the appropriate CAD program. You have to manually measure the entire building, but you are building a CAD model as you go. This eliminates the time needed to transpose your hand-written measurements into a CAD model.
One advantage of this method over laser scanning is initial cost. Laser distance measure is very economical, at least in terms of up-front costs. A Leica DISTO D8 costs about $800 and can transmit measurements to AutoCAD.
In Conclusion
With a good model, you can perform analyses on building performance, visualize new design options, and quickly mark components to be preserved or demolished. Capturing and creating a good 3D model of existing conditions is important for establishing a good foundation for any BIM project. If you can do it faster and cheaper than before, then it might be time to trade in the red pen and clipboard. There are many architectural drafting and BIM consulting firms in USA. BluEnt BIM is a Texas based leading BIM model, drafting, and construction documentation services provider. They help top home builders, developers and construction firms to implement BIM software and develop 3D existing condition models more quickly and accurately.
The use of Building Information Modeling (BIM) for renovation projects can bring in huge benefits in terms of time and cost saving. Despite many advances in technology, designers, contractors and engineers are still tracing over the paper documents of our predecessors while making a plan for renovation.
The design workflow for a renovation starts with some sort of accounting for all of the existing conditions that will be affected by the project. The architect procures as many of the old design documents or paper sheets as he or she can. There is a bigger chance that the paper sheet set may be incomplete, or not reflective of all renovations and changes made to the building since its initial construction. So, the architect performs field-measurements to fill in the missing information, and to check the as-built conditions versus the design documents.
Before the new design proposals can be done, the architect has to engage in tracing over the existing drawings. Once the existing drawings are traced and reconciled with the field measurements, only then the architect can proceed with the new design proposals.
This process takes a considerable amount of time. When you add BIM, it becomes even more time-consuming. How do we transform an existing building in all its glory into a 3D digital model suitable for BIM purposes? The article describes two methods you can use to start the design of your renovation project 'without a trace'. They are:
A. 3D Laser Scanning
B. Laser Distance Measures
A. 3D Laser Scanning
This method is comprised of a couple of steps:
- A 3D laser scanner is used to scan the exterior and interior of a building.
- The laser scanner captures individual data points that when viewed in a single file are a highly accurate model of the building, both dimensionally and visually.
- The laser scanner generates a point cloud file which you import into a CAD program.
- Using the point cloud file as a guide, you then create a 3D CAD model using the 3D modeling software of your choice, such as Revit or ArchiCAD.
3D laser scanning offers several advantages. The point clouds can be very detailed, and can capture very intricate detail within a few millimeters of accuracy. The laser scanner automatically captures adjacent site conditions when it is used to capture exterior conditions of the building.
With the laser scanner method, you still have to manually create a BIM model using the point cloud as a guide. The upside is that the point cloud is in 3D and accurately reflects the actual construction. You can detect walls or floors that are out of square. There are some software tools that can transform some of the point cloud data into a partial BIM model, such as PointCloud from Kubit.
B. Laser Distance Measures
With this method, you field-measure the building using a hand-held laser distance measure. Measurements are transmitted wirelessly from the measure to a laptop running the appropriate CAD program. You have to manually measure the entire building, but you are building a CAD model as you go. This eliminates the time needed to transpose your hand-written measurements into a CAD model.
One advantage of this method over laser scanning is initial cost. Laser distance measure is very economical, at least in terms of up-front costs. A Leica DISTO D8 costs about $800 and can transmit measurements to AutoCAD.
In Conclusion
With a good model, you can perform analyses on building performance, visualize new design options, and quickly mark components to be preserved or demolished. Capturing and creating a good 3D model of existing conditions is important for establishing a good foundation for any BIM project. If you can do it faster and cheaper than before, then it might be time to trade in the red pen and clipboard. There are many architectural drafting and BIM consulting firms in USA. BluEnt BIM is a Texas based leading BIM model, drafting, and construction documentation services provider. They help top home builders, developers and construction firms to implement BIM software and develop 3D existing condition models more quickly and accurately.
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