Case Study: Consulting Engineering

Gamble Montessori High School

Cincinnati, OhioCincinnati Public Schools

An Innovative Approach to a Historic Renovation

Constructed in the early 1920s, the historic Mercy High School has served Cincinnati students for 100 years. The historic campus is built on a 14-acre site with four buildings, totaling slightly over 143,200 SF. In September of 2018, the building was purchased by Cincinnati Public Schools (CPS) to provide space for nearly 1,000 students in the upcoming 2019 school year. To accommodate students for academic success, CPS hired CMTA to completely gut, renovate, and open the renamed James N. Gamble Montessori facility by August of 2019.

The Challenges

  • Renovate building on fast-track schedule (less than half the time of a standard project)
  • Complete historic renovation within budget, even under compressed schedule
  • Preserve historic integrity of the building while modernizing the MEP systems
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We very much look forward to digging in with the community so that we can honor the legacy of this educational institution, and build upon it to do something amazing for kids. Created with Sketch.

Mike Moroski

Board Member & Legislative Liaison - Cincinnati Public Schools

The Solutions

While turning this 100-year-old building into a state-of-the-art high school was always the project’s primary goal, the restricted timeline for design and construction made deep energy retrofits a challenge. However, even with the limited time to design and construct the facility, CMTA worked with the design team to implement as many energy efficiency measures as possible to help the school meet its energy and operational goals.

Beginning with the demolition of old mechanical, plumbing and electrical equipment, the renovated Gamble Montessori High School has new HVAC and electrical systems, 21st Century technology, new kitchen and dining spaces, and all newly renovated classroom and support spaces. Renovations included removing walls, a new state-of-the-art kitchen & dining facility for 800 students, replacing single-pane windows with insulated windows, and tuckpointing exterior walls to repair the ailing building. HVAC systems were replaced with water source heat pumps connected through a two-pipe condenser water loop to new high-efficient condensing boilers and a cooling tower. Areas where rooftop units were added back, and two new dedicated outside air units with energy recovery, were added to provide ventilation for the building, which allow the ceilings to be maintained at their original 11’ to 12’ height.

A water source heat pump system with DOAS units was selected due to the system’s inherent energy efficiency, the building’s floor plan being suitable to accept the system type, and minimal visible outdoor equipment allowing the building to keep its historic character. LED lighting was added in conjunction with daylight harvesting with an average of 0.45 watts/SF, a reduction of nearly 50% under ASHRAE 90.1-2013. The building envelope was also analyzed, which led to the decision to replace the windows with insulated ones. This allowed the central heating plant capacity to be reduced by 29% and the cooling plant capacity to be reduced by 24%. CO2 based demand-controlled ventilation was implemented in the gymnasium to limit overventilation of the space. The yearly consumption of the building as predicted is 53 kBtu/SF year and is currently tracking below 50kBtu/SF year.

Cost Reductions Under Tight Deadlines

To meet the project’s unforgiving timeline, CMTA researched national purchasing partners, like OMNIA Partners, to streamline all purchasing and installation of significant equipment - all while bringing in a traditional General Contractor and subcontractors to install the balance of the systems. Typically, a project under such a compressed schedule would be subject to inflated costs. Therefore, the challenge was not only to complete the renovation on time, but to ensure the project was kept within budget.

The solution we provided was a unique project delivery method in the State of Ohio, utilizing an Intergovernmental Purchasing Alliance (IPA), which acts as a cooperative procurement agency. This delivery method allowed CPS to purchase HVAC equipment before design completion, and prior to the project going out to bid, which kept the project on schedule despite long lead times on some of the equipment. Additionally, ordering equipment through the IPA at negotiated price points removed the risk of cost inflation due to the restricted timeline. Since the building’s age increased the risk of extensive change orders on the project, the IPA also ensured these change orders would be priced fairly per the industry standard. This approach allowed construction to start in less than six weeks from the start of design.

The Results

Starting with a 100-year-old building in desperate need of rework, the design and construction teams delivered a 21st-century school building with major thermal comfort and IAQ improvements, energy efficiency improvements, reduced environmental impacts, and simplified operation and maintenance requirements. All accomplishments were achieved in less than half the time of a standard project, and at half the expected cost.

The building energy usage is 11% below baseline when excluding Covid-19 operations, and dramatic improvements to occupant comfort were achieved. CMTA is proud to have partnered with Cincinnati Public Schools to provide a modernized, energy efficient building for their students.

Gamble Montessori Energy Use

[{"x":"JAN","Baseline":"10.3","Performed":"5.5"},{"x":"FEB","Baseline":"19.9","Performed":"10.6"},{"x":"MAR","Baseline":"27.0","Performed":"15.6"},{"x":"APR","Baseline":"33.4","Performed":"19.8"},{"x":"MAY","Baseline":"37.5","Performed":"23.5"},{"x":"JUN","Baseline":"40.1","Performed":"24.1"},{"x":"JUL","Baseline":"43.2","Performed":"25.6"},{"x":"AUG","Baseline":"45.5","Performed":"27.7"},{"x":"SEP","Baseline":"48.2","Performed":"32.2"},{"x":"OCT","Baseline":"52.3","Performed":"36.3"},{"x":"NOV","Baseline":"60.5","Performed":"39.2"},{"x":"DEC","Baseline":"70.0","Performed":"43.3"}]
What does this data mean?
Baseline: AIA 2030 Annual Energy Use Goal
Actual: The Measured Energy Use of This Project