In a previous article on the GovDesignHub, we sat down with Amr Raafat, Chief Innovation Officer (CIO) at Windover Construction, to discuss the company’s award-winning renovation of the Cabot Street YMCA, located in Beverly, Massachusetts. This project involved vertically expanding the historical 120-year-old building to increase the affordable housing units from 45 single occupancy rooms to 67 studio apartments – helping to alleviate the community’s affordable housing crisis.
Windover Construction’s project not only helped their community but also redefined what is possible to advance historic preservation and the existing building process. The company’s use of Virtual Design and Construction (VDC) solutions – such as BIM – enabled work to be done while the YMCA remained in use for the initial phase of the project. Existing conditions modeling and BIM models also allowed Windover to blur the lines between manufacturing and constructing by leveraging prefabricated parts.
In the second part of our conversation with Amr, we talk about the innovative solutions used for the Cabot Street YMCA renovation, the challenges Windover Construction faced during the project, and how prefabricated parts can be beneficial, especially in a historic building.
GDH: As this was a renovation of a historic property, I would assume that there were no existing 3D/4D models of the space or even CAD files for the building. How was existing conditions modeling done on this project? What technologies and innovative solutions/approaches were used to create models of a building that was already standing?
Amr Raafat: That’s a great point. We laser-scanned the building twice, almost six months before we started construction. The laser scanning before construction helps bridge the gap between what was documented 50 or 100 years ago and what’s happening right now with the building. Design drawings were built that presented what happened to the building over the years.
The Windover team laser-scanned the building with a scanner that has an accuracy of one to three millimeters – that’s very accurate. Because of this laser scanning, we delivered an existing condition 3D model of the building to the design, engineering, and architecture teams.
This allowed us to start updating the design early in the process and confirm that the building’s beautiful design fit perfectly into the laser scan model we built in Revit. During this process, we had to ensure that construction would preserve the historic facade, which was critical.
“Data is essential, but utilizing it innovatively is truly important.” — Amr Raafat
We then laser scanned again after the demolition of the roof, which was very challenging, and scanned inside the building as well. This was done because after we demolished the roof, we uncovered things that were not known when the building was in its original condition. Next, we communicated these findings to the architect and engineer, as well as the folks who were creating the steel beams. Together, we made decisions about the sizes of the new structural and architectural elements, which enabled us to increase the tolerance to fit even more.
Data is essential, but utilizing it innovatively is truly important. The laser scan leverages millions of laser beams that hit a surface and transmit a dot. This results in millions of dots that represent the scanned surfaces to the millimeter. This highly accurate data helps mitigate the risk in real-time through the BIM coordination process.
GDH: Was the Cabot Street YMCA still in use when the renovation and expansion were being conducted? If so, did the company have to operate and work around the YMCA’s usual operations? How was this planned, organized, managed and executed?
Amr Raafat: In this case, the building was occupied by residents and YMCA officials during the early phase of the project. This issue was very logistically challenging; we needed to ensure that every occupant would be safe during construction.
“We conquered this challenge through clear communication, logistics, 4D communication, and Windover Construction’s enhanced optimized safety planning.” — Amr Raafat
The way we overcame that was through clear logistics and planning with the BIM models and animations. We developed a deeper understanding of the logistics and ensured a separation between the occupied area and the area under construction in the 3D/4D construction sequence.We then collaborated with the superintendent, project management, and VDC team to communicate clear phasing expectations.
In our plans, we showed the separation between occupied areas and construction areas and communicated that separation to our trade partners in order to support the safety and logistics plan. This was a big part of the challenge of maintaining constant safe access to the building at all times for occupants during the first phase of construction. We conquered this challenge through clear communication, logistics, 4D communication, and Windover Construction’s enhanced optimized safety planning.
There was a hard deadline for the project to be completed before the Christmas holiday so residents could move back into the building. Because of this, it was crucial to stay on schedule. With the help of our technology and laser scanning, we were able to mitigate risks and keep the schedule on the right track.
GDH: One of the large trends that we’ve witnessed in the AEC industry is the blurring of the line between AEC and manufacturing. I understand that prefabricated parts were utilized in this project. Why were prefabricated metal components utilized? What purpose and function do these particular prefabricated parts have on the finished project?
Amr Raafat: Windover Construction is one of the experts in prefabrication and modular construction; we are the go-to in the New England area. We have experienced project managers, superintendents, and VDC teams who specialize in building with modular and prefabricated components and parts.
“The project was a global collaboration to test and start using telescopic technology for the first time.” — Amr Raafat
Windover Construction is a resident of the Autodesk Technology Center, so we partnered with Autodesk on this specific project. We also partnered with Howick, a company in New Zealand that is a leader in making machines that produce studs, as well as the Canadian company StrucSoft which is creating software to make machines work with BIM models.
The project was a global collaboration to test and start using telescopic technology for the first time. We manufactured these telescopic parts using the BIM data and coding generated by Windover Construction.
When the telescopic parts traveled to the Cabot YMCA job site, they were compact. The compactness was especially efficient because the building had tight corridors and elevators. When the prefabricated parts arrive at the intended location, they can expand and adapt to any height up to the ceiling.
One of the reasons we applied telescopic technology was that when we laser-scanned the building before construction, we found that the ceilings had different variations of ceiling heights. The advantage of this adaptive manufacturing industrialized construction technique is that these telescopic walls and studs can adapt to any ceiling height and can frame around the window. This new technology saves 70% of framing time compared to traditional methods in addition to minimizing material waste.
GDH: Why is prefabrication a viable solution for projects like these? What benefit does the prefabrication of parts deliver? And how does BIM modeling enable prefabrication? Would prefabricated parts really be possible without accurate models?
Amr Raafat: The prefabrication model will help us reach our quality goals because all the prefabricated elements are made in a factory where you can control quality. But it relies on a detailed, accurate BIM model to work effectively.
“This project has been a global collaboration to define what is possible to advance the manufacturing industry with BIM data.” — Amr Raafat
It is becoming a standard for Windover Construction projects that we have a very detailed BIM model. The BIM model gets developed, and then more data is added and becomes more accurate as you go. This BIM data ends up being very detailed and information-rich, which actually carries over when you fabricate pieces. We use this method with modular construction and prefabrication.
Prefabrication helps us save time on-site and is logistically easier and safer. An additional big advantage of prefabrication is sustainability. This is because when parts are made in the factory, we can save on energy and use especially efficient techniques in a factory setting. At Windover, we’ve been focusing on transforming construction with prefabrication and modular construction not only to support sustainability initiatives but also to increase the product quality you get from these technologies.
This project has been a global collaboration to define what is possible to advance the manufacturing industry with BIM data. BIM data doesn’t have to stop at visualization or coordination and mitigating risk; it can also carry over into the making of things and fabrication.
To read the first part of our interview, click HERE. To learn more about Windover Construction’s award-winning project, click HERE.
