Peak Performance for a Historic Building
Grand Junction, CO
General Services Administration
AIA COTE Top 10
Originally designed under Treasury supervising architect Wetmore, the Aspinall was first constructed as a U.S. Post Office and Courthouse in 1918. In 1939, a substantial addition extended the building to the east. The three story multi-use building houses the U.S. District Courts and various federal agencies. Delivered using an innovative design-build model, in partnership with the Beck Group, the project incorporates a ground-source heating and cooling system, a 123 kW photo-voltaic system, user flexible controls, and abundant daylighting and views.
Restoring Historic Character
Lobby design includes replacement of historic fixtures based on original supervising architect James Wetmore’s design; restoration of historic floors; and repurposing the west portion as both tenant and visitor amenity. On upper floors, reconfiguration of non-original fire walls and doors between elevator/stair lobby and corridors creates an open layout and restores continuity in circulation present in the building’s early life. A new security station and exterior accessible ramp were added. Interior renovations include government agency spaces and comprehensive infrastructure replacement.
New elements in the lobby area harmonize with historic fabric, yet make a clear distinction between the new and historic features, which were restored and preserved.
Original maple flooring defines work areas.
The project preserves the dignified, historic significance of Grand Junction’s crown jewel, while modernizing the landmark with sustainability, vitality, and usefulness for tenants and community. In the Central Business District of a community serving as regional anchor, the project demonstrates reinvestment and partnership with a progressive, supportive community to reinforce urban fabric and livability, including access to the city’s adjacent alleyways to install 12 of the geo-exchange wells to achieve site energy goals.
Exterior improvements respect the historical component of the limestone and brick masonry façades of the original 1918 building and 1939 addition that contribute to the building’s historic significance.
Enhanced pedestrian access includes new ABAAS compliant entrance ramps, including a new ramp at the south entry to provide a greater sense of dignity and efficiency.
Existing Thermal Mass
Grand Junction is located in ASHRAE Climate Zone 5B, which experiences a wide range of dry bulb temperature, with low overall relative humidity throughout the year. Rainfall is limited to under 10 inches per year. Solar availability for renewable energy generation is high. The existing building consists of a high thermal mass construction, which was augmented with interior insulation systems, to retain the benefits of thermal capacitance to increase the thermal stability of the internal environment, while allowing HVAC systems to react more quickly during morning warm-up and cool-down.
In order to meet the Secretary’s Standards for Rehabilitation, photovoltaic panels and their mounting structures can be reversed and removed from the building.
The design team maintained the historic appearance of existing fenestration systems, while reducing solar gain and thermal conductance, using new internal storm windows with a high-performance spectrally-selective film.
Bright and Comfortable
Lighting is upgraded to efficient state-of-the-art technology with wireless controls and integrated with HVAC to achieve visually comfortable work environments. All perimeter zones include design features to allow for balance of energy efficiency and visual comfort.
A skylight was installed over the main tenant space on the first floor, to allow deeper daylight penetration in the largest open office area in the building.
On the second and third floor, perimeter ceiling zones are kept free of building services, to allow maximum daylight penetration.
Long Life, Loose Fit
The project is innovative in balancing sustainability and historic preservation. It creates awareness of measures that can reduce energy use in a historic structure without a material impact on the historic fabric, and demonstrates the use of alternative energy that can supplement traditional conservative methods, to allow historic buildings to achieve minimal to zero net energy use and energy independence.
The use of a variable refrigerant system allows additional fan coil units to be added, if needed, in the future.
The basement area can be utilized as a shelter during extreme events.