Zero Energy Certified



Certification StatusZero Energy Certified
LocationColumbia, MD, USA
Project Area106,622 SF
Owner OccupiedYes
Occupancy TypeEducational
Number of Occupants800


OwnerHoward County Public School System
Project ManagerHoward County Public School System
General ContractorOak Contracting, LLC
ArchitectTCA Architects, LLC
MEP EngineerJames Posey Associates, Inc.
Lighting DesignJames Posey Associates, Inc.
GeotechnicalHillis-Carnes Engineering
Civil and LandscapeFisher, Collins & Carter, Inc.
StructuralJohnson Engineering
Roofing EngineerGale Associates
Solar EngineerSepiSolar, Inc
Acoustical EngineerMiller, Beam and Paganelli, Inc.
Daylighting EngineerEMO Energy Solutions
Photo Courtesy of Wilde Lake Middle School


Wall R value and section specification25. Typical wall section includes R-22 insulated metal wall panel system on CMU backup at second story areas and conventional masonry cavity wall construction (face brick, insulation, CMU backup) for first story areas below. The conventional masonry wall utilizes R-25 spray polyurethane foam (SPF) insulation.
Roof R value30
Window to Wall Ratio20%
Window U Value0.24
Windows Description
Typical window is double-pane Low-E glazing inside of a 7- 1/4″ deep aluminum curtainwall framing system. Sunshades and calculated, variable Low-E coatings are used on south, east and west-facing elevations.
Air infiltration rate and sealing protocol0.089 cfm/SF allowed; The entire building utilizes a continuous air barrier system to minimize air leakage. The SPF forms a monolithic air barrier at typical cavity wall construction that seals around all cracks and gaps. Fluid-applied air barrier is utilized on CMU backup behind metal panels. Expansion and contraction joints are handled with high-performance sealants. Self- adhering membrane was applied at all material terminations, transitions between dissimilar materials and around all openings, such as windows. The air barrier system was specified to include pressure-testing. The onus of passing the pressure test was placed onto the Construction Manager, starting at the beginning of construction. The CM therefore carefully monitored the installation of all air barrier components and promptly made repairs to seal any penetrations made through the barrier by various sub- contractors.


Ground-source geothermal system comprised of 112 400-foot deep vertical boreholes. All water system, with a single pump provided for fluid distribution. 71 two-stage water-source heat pump units for space conditioning throughout the classroom and assembly areas. Water-cooled VRF system for space conditioning within the administration areas.


Three independent DOAS units headered into one DOAS system, each provided with enthalpy wheel and chilled/heating water coil. VAV terminal units modulated ventilation based on room C02 levels.


Water is heated from a ground source heat pump.


Whole building networked lighting control system is utilized to control sensors – occupancy and vacancy – relays, devices, and LED luminaries with digitally addressable drivers. Daylighting plays a strong role as well.

Photo Courtesy of Wilde Lake Middle School


Panel Array Size663 kW
Panel Output per Capacity Nameplate310 W
Panel Quantity2044
Panel Type and BrandTrina 310 W
Inverter Quantity19
Panel LocationRoof and Ground-Mounted
Ownership DetailsOwned by HCPSS


Actual energy use during performance period428,301 kWh
Actual energy produced during performance period821,618 kWh
Net Energy Use-393,317 kWh
EUI13.7 kBTU/sf/yr


Wilde Lake Middle School (WLMS) is provided with an on-site natural-gas fired generator (rated at 150kW-277/480V-3PH-4W) to provide power for emergency egress lighting and for other “essential” loads required by the Howard County Public School System (HCPSS). “Essential” loads required by HCPSS include the kitchen walk-in freezer and walk-cooler, other refrigerators located within the school, and security + AV/IT equipment located within the main and intermediate telecom rooms. Provisions for an on-site natural-gas fired generator is an Owner requirement for all HCPSS projects.

The on-site generator is the only natural gas source at WLMS. The on-site generator at WLMS is surrounded by CMU block walls on three sides with the gated opening facing wooded areas. The on-site generator complies with U.S. Environmental Protection Agency (EPA) exhaust emissions regulations and is certified to conform with Section 213 of the Clean Air Act (42 U.S.C. section 7547) and 40 CFR Part 60.

For maintenance purposes, the on-site generator is only exercised once a week (every Monday morning) for a maximum of one-hour. The only other time the generator operates is during utility power outages.

Photo Courtesy of Wilde Lake Middle School