Automated Modeling + Drawings from Site Measurements / by Daniel Giuffre

This article is part of a series that documents our involvement in the Forrest Chase Redevelopment.

Rhino + Inventor: Sheet Metal

Rhino + Grasshopper: Sheet Metal Bending

Drawing Automation

Drawing Automation From Site Measurements, Part 1 | Rhino + Grasshopper

Drawing Automation From Site Measurements, Part 2 | Rhino + Grasshopper

Documenting for fabrication requires modeling at an increased level accuracy than possible from design models, however, sometimes it is not feasible to get a site survey scan. Working with Denmac, if/Lab has developed a workflow that seamlessly transfers simple site measurements into the production of fabrication drawings for sheet metal panels; increasing accuracy whilst eliminating the need for repetitive manual documentation processes. 

Diagram: Site Measurements to 3D model

Diagram: Site Measurements to 3D model

The process begins with workers on site measuring panel regions and location of intersecting geometry; providing if/lab with a sketch of the panel sizing or distances and set out points. From here these hand-drawn measurements are entered into inputs of the grasshopper script producing 3-dimensional geometry and fabrication documentation.

Example of on-site measurements received.

Example of on-site measurements received.

After the geometry is produced by the script, the onsite measurements are checked against the structural model to foresee any major issues or errors that may have been missed onsite. The review process allows feedback from design, fabrication and installation personnel to comment and changes to be made before the panels arrive onsite saving time and money.


After the changes have been made and the 3D model is deemed correct by review process the shop drawings and laser cutting files are updated directly from the model and issued for fabrication without the need for manual changes. After the panels arrive on site the installation team can review and check how the elements are to be installed by referencing the 3D model and reference imagery, reducing the ambiguity of traditional 2-dimensional drawings, increasing the efficiency of the installation process.

intensive fields lab_forrest chase detail

By allowing for the input of low-tech and cheap site measure processes combined with seamless modelling, review and documentation processes, If/lab has been able to assist in closing the gap between the design, fabrication and installation team to create a fast, cheap and accurate solution to a complex construction problem without the need for costly technology.

Forrest Chase Complete