Case Study

George T. Douris Tower

Energy recovery transforms senior affordable housing

This case study was chosen as part of the Empire Building Challenge competition. Click here to learn more about the Empire Building Challenge competition.

Project Highlights

Lesson Learned

The Resource Efficient Decarbonization (RED) methodology helped generate various technical and financial scenarios for the project, ultimately allowing selection of the optimal pathway.

Project Planning

The project creates a unique thermal connection between previously disparate spaces within the building. Residential spaces will be thermally connected to non-residential service spaces including a commercial kitchen and office to facilitate energy recovery.

Project Planning

The project utilizes existing technology in an innovative application, along with displacement strategies, to maximize cost-efficacy of the project.

Step 1

Step 1: Examine Current Conditions

A baseline assessment is key to understanding current systems and performance, then identifying conditions, requirements or events that will trigger a decarbonization effort. The assessment looks across technical systems, asset strategy and sectoral factors.

Building System Conditions

Equipment nearing end-of-life
New heat source potential
Comfort improvements
Indoor air quality improvements
Facade maintenance
Efficiency improvements

Asset Conditions

Recapitalization
Capital event cycles
Owner sustainability goals

Market Conditions

Market supply changes

The building’s main HVAC equipment is still in place from the original construction and is nearing the end of useful life. This aligns with the 15-year recapitalization cycle for affordable housing which the building is undergoing in parallel with the decarbonization plan. Without this alignment, the building may have struggled to complete the remaining measures by 2035. The project will improve the quality of life for residents by increasing their ability to control space temperatures throughout the year, improving indoor air quality, and reducing the amount of noise heard from outside the building.

Step 2

Step 2: Design Resource Efficient Solutions

Effective engineering integrates measures for reducing energy load, recovering wasted heat, and moving towards partial or full electrification. This increases operational efficiencies, optimizes energy peaks, and avoids oversized heating systems, thus alleviating space constraints and minimizing the cost of retrofits to decarbonize the building over time.

Existing Conditions

This diagram illustrates the building prior to the initiation of Strategic Decarbonization planning by the owners and their teams.

Click through the measures under “Building After” to understand the components of the building’s energy transition.

Sequence of Measures

2027

Building System Affected

heating
cooling
ventilation

Electrical Upgrades and Grid-Interactive Controls

Future Thermal Energy Network (TEN) Connection

Cooking Ranges & Commercial Dryer Electrification

Step 3

Step 3: Build the Business Case

Making a business case for strategic decarbonization requires thinking beyond a traditional energy audit approach or simple payback analysis. It assesses business-as-usual costs and risks against the costs and added value of phased decarbonization investments in the long-term.

Decarbonization Costs

~$33M

Central Mechanical Plant: 770k.

Commercial HVAC: 1.2M.

Terminal Unit Replacement: 9.4M.

AWHP: 3.8M.

Grid Interactive Controls: 20k.

Wastewater Heat Recovery: 830k.

Drain Energy Recovery: 30k.

Window Upgrades: 2.6M.

Wall Insulation: 2.9M.

Ventilation Upgrades: 800k.

Solar PV: 310k.

Electrical Upgrades: 1.2M.

Commercial Dryer Electrification: TBD.

Residential Cooking: 290k.

Commercial Kitchen Electrification: TBD.

Additional Electrical Upgrades: 7.3M.

Additional Heat Pumps: 1.6M.

Business-as-Usual Costs

$1.5M

Energy cost savings: -70k / YR

BAU cost of system replacement/upgrades: 1.5M.

Business-as-Usual Risks

$0

Local Law 97 or other regulatory fines: 0.

Decarbonization Value

$3.92M

Incentives (estimated): 3.9M.

Net Present Value

-$25.4M

Standard escalation, user input scenario from USGBC tool

The business case for the property is centered around the 15-yr recapitalization cycle. Throughout the project, the team fought the simple market factor that electricity is just under 4 times more expensive than natural gas at this building. It became clear during the project that while minimizing capital costs was important, the main driver of the business case would be to develop a suite of measures that reduced, or kept neutral, operating costs while providing deep carbon reductions and other benefits to the building and residents.

Strategic Decarbonization Action Plan

An emissions decarbonization roadmap helps building owners visualize their future emissions reductions by outlining the CO2 reductions from selected energy conservation measures. This roadmap is designed with a phased approach, considering a 20- or 30-year timeline, and incorporates the evolving benefits of grid decarbonization, ensuring a comprehensive view of long-term environmental impact.

The decarbonization roadmap underwent significant evolution throughout its development. Initially, plans centered on a geothermal system installed in the building’s parking area. This approach was extensively discussed during the design charrette, but the project team ultimately encountered two main issues with this approach that caused them to re-think the approach:

Drilling in the garage space would have been very disruptive to the residents and the space is currently leased to a third-party to operate the parking garage. Any type of activity in this space would have caused lease issues and delayed, or potentially cancelled, the project.
The cost of the geothermal equipment was not commensurate with the carbon and operating cost reductions that were expected.

After discussions with NYSERDA and other stakeholders, the team pivoted to a displacement approach using technology that, while having a lower COP, had a lower initial cost and would provide carbon reductions on a similar order of magnitude compared to geothermal.

The window and envelope measures were prioritized as part of the initial decarbonization phase to capitalize on construction coordination and to take advantage of the building’s recapitalization cycle. If this had not been done, it is likely that the measures would not have been installed until the next recapitalization cycle which might not have occurred until 2040.