The grandest remaining piece of Schenectady’s long-lost trolley system headquarters will be restored and become — literally — the crowning feature of the building’s latest incarnation.

Workers made a surprise discovery recently while preparing 512 State St. for renovation into apartments and a restaurant: The ornate arched plaster ceiling survived, largely intact and in remarkably good shape, considering it likely dates to 1913. The drop ceiling that had concealed it for decades probably kept it from damage.

The non-descript, three-story brick exterior of the building gives little clue to its original design, a wide-open, single-story waiting room for the Schenectady Railway Co., with a massive arched window facing onto State Street. The interior is even less inspiring, having been chopped up into three floors and used most recently as a single-room occupancy boarding house.

Owner Jeffrey Buell, of Sequence Development, said the discovery altered his plans for the building.

“This can’t be cut up into apartments,” he said. “This is one of the finest examples of what Schenectady was doing 110 years ago.”

The plan now is to re-create the arched window; create a soaring two-story space for Slidin’ Dirty, the gourmet hamburger restaurant that is expanding to Schenectady from Troy; and create a single duplex office space with the newly rediscovered ceiling overhead.

Some work needs to be done to restore the ceiling, as the lower edges were cut away in places to fit walls and ceilings for the boarding house. It’s a very specialized skill, but Buell has found someone who can take a cast of the intact parts of the ceiling and re-create the missing portions.

Beyond that, “it really just needs a healthy cleaning,” he said.

Buell was visibly excited while leading a tour and describing the changes that will be made to what is now a badly run-down space. The resulting office space will be unique, historic and striking, he said, and probably will appeal to a specific kind of tenant.

The occupants of the space, Buell said, will see a benefit in being part of the city’s past and its future at the same time — occupying a building with elements of a 1913 waiting room looking out onto a stretch of street that has been transformed and revitalized over the past decade.

The concept of re-creating the entire trolley station — one great open hall with the arched ceiling above — is not economically feasible, however nice the idea might be.

Sequence has accomplished what it set out to in the first phase of the project: conversion of the derelict Foster Building at 508 State St. into retail space and 11 upscale apartments (one of which is Buell’s own residence). Phase two focuses on three neighboring buildings: 510 State, 512 State and 204 Lafayette St.

The Schenectady Metroplex Development Authority sold all four buildings to Sequence for $475,000, after spending nearly $1 million on lead and asbestos remediation and hauling out 600,000 pounds of debris.

Sequence spent $2.8 million to overhaul the Foster Building and will spend $4.2 million on the other three buildings.

The beauty and potential of the Foster Building, though badly faded, was readily apparent as work began. The circa-1910 building, with its soaring columns, started life as a hotel. But almost every defining characteristic of the trolley station was gone or covered up. So, discovery of the ceiling was a surprise.

“Everyone thought it was just a nondescript brick building,” Metroplex Chairman Ray Gillen said.

Work is underway to make it much more.

Elizabeth Young Jojo, of Sequence Development, said Slidin’ Dirty’s new space, which will also host its catering operation, should be ready by late spring or early summer.

Much work needs to be done on the rest of the building: The marble treads on the cast-iron staircase are crumbling; the walls separating rooms in the boarding house need to be knocked down; the paths of entry for birds need to be found and sealed; some philistine painted over the marble walls in the old Railway offices.

And the great arched window needs to be rebuilt.

“We need this building to really pop,” said Buell, explaining it will be part of what drives foot traffic farther up State Street and increases the walkability of downtown Schenectady.

Buell and his development company have the stated priority of preserving historic properties and developing space with consideration of its role in the larger identity of a downtown area, as evidenced by similar projects undertaken in downtown Troy.

He expects the second and final phase of his State Street project to be finished by the end of the year.

Reach business editor John

Cropley at 395-3104, john@ dailygazette.com or @ cropjohn on Twitter.