Closed since 2004, the building had fallen into disrepair with “a partial roof collapse, exterior wall displacement, deteriorated slate and mortar joints, and widespread window failure, leaving the structure vulnerable to ongoing water infiltration and loss of historic fabric,” Huntley says.

“Some of the building envelope masonry suffered extensive damage as a result of roof leaks and deterioration due to freeze/thaw cycles,” she adds.

Gale, a consulting engineering firm, was retained by the State of Maine Bureau of General Services in 2021 “to evaluate stabilization options and develop a preservation-based strategy to secure and restore the building enclosure,” Gale notes. The project is funded through $20.4 million in state bonds.

Closed since 2004, the Stone Building had fallen into disrepair with a partial roof collapse, exterior wall displacement, deteriorated slate and mortar joints, and widespread window failure.
Photo courtesy of Gale Associates

The project involves restoring about 50 historic wood windows, including original stained-glass units, to meet modern energy codes, says Alan Pinciaro, project manager at Bedford, N.H.-based Gale Associates. A total of 800 windows are set for replacement.

“Due to the size of the building, the restoration work has been conducted in phases as funds are available,” Huntley says.

Once fully restored and occupiable, the state plans to relocate some of its agencies that are currently occupying leased space into the Stone Building.

Following eight months of design, Benchmark Construction, the general contractor, began work with roof and building envelope masonry repairs in 2022. The RC Group conducted abatement in 2024 to remove “hazardous materials and selectively salvage significant interior historic woodwork in coordination with the Maine Historic Preservation Commission,” Huntley says.

After four months of design, Benchmark began window repairs and replacements in late 2024. “Existing windows were removed to allow repairs to deteriorated brick masonry backup walls at the perimeter of the rough openings, while window components identified for restoration were transported off site for specialized repairs,” Pinciaro notes.

Gale conducted visual and selective destructive investigations to document the building’s architectural features, says Pinciaro, who noted that for visual investigations, the team “used handheld equipment including a borescope camera, a drone, and binoculars to assess the as-built condition at locations not easily accessible or visible from grade.”

The team conducted destructive testing to remove select areas of the as-built building components to expose the original methods and materials of construction. Crews, for example, removed and repaired “areas of roof membrane, asphalt shingles and slate shingles to expose the layers of insulation, underlayment and the exterior surface of the roof deck structure,” Pinciaro notes.

Contractors have replaced the roof, repaired decorative copper flashing and masonry on the historic Maine Stone House.
Photo courtesy of Gale Associates

Gale coordinated with the state bureau and state commission to install a synthetic slate system made with recycled content that replicated the size and color of the original slate roof sourcing materials, Pinciaro says. The synthetic shingles were EcoStar Majestic Niagara Slate, which utilizes up to 80% post-industrial recycled materials using mostly polyolefin, thermoplastic polymers used in packaging, automotive parts, medical equipment and consumer goods. “This allowed the project to proceed on schedule using durable contemporary materials,” he says.

The AGHI, initially built between 1836-40 with four additions completed between 1848-70, reflects nineteenth-century institutional mental health planning based on the the Kirkbride Plan, Gale says.

The building is a complex architectural structure that “reflects nearly 200 years of evolving architectural styles, construction techniques and material systems,” Pinciaro says. “The combination of multiple historic additions and significant deterioration created substantial complexity in developing a preservation and rehabilitation strategy for the building enclosure systems.”

Gale used drone surveys and other technology to create detailed 3D models of the facilities, which allowed the team to “accurately catalog the building’s historic character, existing building systems, and areas of deterioration within the as-built conditions,” Pinciaro says.

Gale then partnered with the BGS and the MHPC to develop a preservation and rehabilitation design that “maintained the facility’s historic aesthetic and defining features while addressing current performance needs,” Pinciaro says.

The RC Group conducted abatement in 2024 to remove hazardous materials and selectively salvage significant interior historic woodwork.
Photo courtesy of Gale Associates

The team also used drones to survey the facility and develop “a detailed point cloud model” during evaluation and design, Pinciaro says. “Constructed from more than a thousand embedded photographs, the model assisted the team in documenting deficiencies, replicating historic building components requiring replacement, and developing two-dimensional photorealistic elevations.”

The team used similar technology to develop floor plans and document the complex brick masonry, arched and cast-in place concrete tunnel systems surrounding the stone building. “This allowed the team to coordinate underground tunnel locations with the contractor and minimize construction vehicle activity above these sensitive areas,” Pinciaro recalls. “The tunnels provide pedestrian access and raceways for various utility lines for the campus,” Pinciaro says.

Preliminary studies for upgrades to mechanical ventilation systems were completed in 2022 and design for temporary heating/cooling is set to begin this summer, Huntley says.