June Membership Meeting

NOTE NEW EVENT LOCATION!

Presenter: Al Bustamante, P.E. of Walker Consultants

Alfredo (Al) Bustamante, PE is a Senior Vice President, the Managing Director of Forensic Restoration and Building Envelope Services, and sits on the company’s Board of Directors at Walker Consultants.  Al has over 20 years of experience in assessing, repairing, and load testing structures. His experience also includes façade evaluation and repair design of different stone cladding materials, curtain walls, brick, and concrete.

Topic: Historic Building Cast Stone Restoration Using UAVs and Photogrammetry

Date: Thursday, June 16, 2022

Time: Social hour at 11:00 AM, lunch at 11:30 AM, meeting 12:00 PM to 1:00 PM

Location: Terracon (Training Room) 8901 John Carpenter Fwy, Ste 100, Dallas, Texas 75247

Cost: $25 member / $35 non-member

Registration: online – use the green buttons at the top of the page (click here if you do not see the green buttons)

This presentation demonstrates how modern technology was used to digitally document the existing condition of isolated architectural features of a building façade, develop 3D models of those features, and utilize the models to form replacement parts in order to restore the façade of a historic hotel in Houston.

Historic building façade restoration projects are usually very complex given that as a designer, our job is to maintain the physical and aesthetic properties of a façade with modern day materials and typically no existing documentation. While traditional methods such as casting are still used to replicate existing façade elements, these methods are typically very costly. The cost mainly comes from providing access to a particular location in the façade to remove an existing element in order to create a mold. In addition, the mold itself is typically hand-crafted and can generally be a lengthy and costly process depending on how ornate the feature is. Finally, access to the unit for duplication usually involves invasive and destructive means and approach with the risk of damaging adjacent façade features.

Today, there are new methods engineers can employ to reduce costs during design and construction as well as limit damages to the existing structure. For one, unmanned air vehicles (UAV) can be utilized to perform a close-up visual assessment of a façade. This allows a designer to assess the general condition of a structure and decide which areas are best suited for the more costly hands-on, up-close assessment. This generally reduces the initial cost of the repairs during the pre-design phase. Moreover, digital scanning technologies provide us with ways to non-destructively 3D model existing structures and building features. The technology utilized for this project is Photogrammetry. Photogrammetry utilizes photographs to create a 3D model of an object by plotting common points from several photographs of the same object. The results are similar to but not as accurate as laser scans. However, the cost is significantly less and the process can be easily executed with minimal effort or disruption.

Overall, the technology used in this restoration project demonstrates how restoration projects can benefit from today’s technology by: 1) Reducing costs throughout the design and construction phases of a project, 2) Reducing the time it takes to draft details of complex elements or decorative features for construction documents, and 3) Providing a contractor or manufacturer with a digital model of a particular building feature that can be 3D printed or milled using a variety of materials.