Three high-traffic sites sit seconds from one another in downtown Deerfield, Ill.
There are the village hall/police department complex, the well-used and -manicured Jewett Park and the Deerfield Public Library. Deerfield is a northern Chicago suburb that sits not too far from Lake Michigan.
On a recent summer day, patrons strolled in and out of the library, enjoying the many comforts the newly renovated building offers.
The library reopened in June after undergoing a massive rehab that added 10,000 sq. ft. and numerous sustainable upgrades. It now offers patrons more than 44,000 sq. ft. of space along with many new amenities and technologies.
One of those technologies that will go unnoticed by the general public is the use of building information modeling during the design and construction process. The use of this advanced visualization tool greatly aided in the planning, installation and integration of the library’s MEP systems and helped keep the construction project on schedule.
Deerfield Library Facilities Engineer Tony Keaton opens a door that reveals a slab of concrete with a steep vertical ladder attached to it that leads into a crawlspace-like opening. When you climb to the top you have reached the library’s penthouse, which houses all the building’s key MEP systems. Fire protection and pumping systems are housed in a lower-level mechanical room.
To say the least, space and ceiling height is limited in the penthouse, which is original to the 42-year-old structure. This presented challenges for the project design and construction teams. Mortenson Construction’s Chicago office was the construction manager, while Rock Island, Ill.-based KJWW Engineering Consultants was the MEP engineer. Dewberry is the architectural design firm of record.
“We had to fit a brand-new MEP system in an existing building that was built more than 40 years ago,” Mortenson Project Manager John Zhang explains. “It has a low ceiling and little room to move around. In some spots there is 18-20 in. of space. We had to heavily rely on BIM and virtual design and construction processes.”
Zhang notes during a 2 1/2-month timeframe last summer, BIM helped lay out the new installation blueprint for the library.
“We were in the office with the MEP and fire-protection subcontractors going over 3D MEP coordination,” he says. “We were able to take the Autodesk Revit model from the design team and send it over to the mechanical, electrical, plumbing and fire-protection contractors who built their entire systems based on the design team model. Those models were sent back to the Mortenson BIM manager who combined the trade models into a federated construction model.”
This process helped resolve many issues before the construction process actually started. “We basically cleared all clashes in the model,” Zhang says. “Everybody signs off on the agreed-upon model. When everything arrives on the jobsite, it’s already coordinated and everybody follows what they signed off on.”
The use of BIM wasn’t limited to the library’s pre-construction stages. A war room of sorts was set up on the construction site where a laptop connected to a flat-screen monitor housed the agreed-upon model, giving all project contractors access to the design.
“People came into the trailer and looked at the model to see if there were any other conflicts,” Zhang says. “That became everybody’s roadmap. Relying on that process, we were able to eliminate 95% of all conflicts and maintain our schedule. We didn’t have any work stoppages because of clashes. Those were all resolved during the initial 2 1/2-month coordination process. The BIM application was a very vital tool we relied on for the library project. Everybody benefitted from the process.”
Zhang says there was initially some question whether the use of BIM on a smaller-scale construction project such as the Deerfield Public Library was necessary.
“Virtual construction, coordination and design are Mortenson’s standard practices when it involves MEP installation,” he says. “With a building of this size, people were skeptical about using this heavyweight design tool. Mortenson understands that at the end of the day, it’s going to help everybody. We require every contractor on the job to use it. You don’t want to risk finding a discrepancy during the construction project and then have to change ductwork or pipe. Those are the types of things that kill construction schedules.”
Zhang adds the use of BIM meant the difference between success and failure when it came to fitting the new systems into the existing penthouse.
“It’s tough to move around in that penthouse,” he says. “It’s an existing structure, so you can’t make it any wider or higher. We had to heavily rely on BIM for this process. We had three extra meetings with everybody involved in the penthouse in terms of looking at the model and deciding who would go in first. It was like making an animation movie. You had to cut out the different scopes in different sequences and then play back the day-by-day to the subs so people had a good idea which contractors were going in first and which ones were going in last.”
Blair Hawn, P.E., who was KJWW’s project manager and lead mechanical engineer for the library design, adds: “BIM technology was critical on this job. This was an existing 42-year-old building that was not built with our future mechanical systems in mind. We had to use every nook and cranny to fit things in. Everything fit and clearances were maintained. BIM was crucial in making all that happen.”
Zhang estimates that 1 1/2 months of construction time was saved by using BIM technology. “We saved time by identifying clashes beforehand,” he says. “When we ran the clashes last July, we found hundreds of them and flushed them out. The owner was so impressed with the process. The Deerfield Public Works director visited our jobsite and took her engineering staff with her. They are very interested in requiring BIM in future projects they do.”
Included in that BIM design model were two new A.O. Smith Cyclone Xi water heaters that sit nestled just a few feet from the penthouse opening. “The old water heater they had was fairly outdated and the owner had safety concerns with how often it leaks,” Zhang says. “The new water heaters are a lot more energy-efficient and are fully insulated. They are connected to the building automation system so the building engineer has the ability to turn on a terminal and look at the exact temperature of the water heaters. They are very happy with the water heaters.”
Hawn notes the use of the Cyclone water heaters enables the library to have a constant supply of hot water. “They had complaints in the original building of running out of hot water,” he says. “They don’t have a great demand for domestic hot water because it’s a library. We circulated the hot water so it’s always available to them at the fixture, which was not previously done.”
The restrooms are outfitted with new Kohler water closets and urinals with Sloan flush valves, Elkay sinks and Sloan sensor-activated faucets. Because of the building’s age, high-efficiency fixtures could not be used. “There is a limited pitch with the pipes,” Zhang says. “With the low-flow fixtures there was risk of pipes clogging.”
On the mechanical side, a new Valent rooftop unit was added along with a variable refrigerant flow system. “Rather than adding a huge rooftop unit like what you normally would do on a project like this, we were able to size down to a much smaller rooftop unit,” Zhang says.
Inside the penthouse, seven small LG VRF units feed down to more than 58 terminal units installed above the ceiling. “With those units working together with the rooftop unit, we’re able to serve the building in a much more efficient way,” Zhang notes. “The whole system operates very quietly. If you are in any space there you barely hear the noise normally related to a rather large mechanical and air-handler system.”
Other sustainable upgrades include the use of sensors on light fixtures and the installation of an atrium area on the west side of the building to take advantage of natural light.
“They have lighting sensibility,” Zhang says. “Individual fixtures turn on and off based on ambient light throughout the day. The lighting control panel is part of the beauty of the automation system. It gives the owner a very scalable and customizable way to control the light to fit their needs, different schedules and different seasons of the year. It’s a nice sustainable feature for a building.”
The new library has drawn rave reviews from patrons and staff members alike. Hawn attended the grand opening and came away impressed with the finished product.
“It was great to see the ribbon-cutting and see kids playing in the expanded children’s area and using iPads there,” he says. “In our business you see things for so long on paper, but it’s different seeing the finished product. The library turned out great. They now have energy-efficient systems that will last the life of the building.”