Seven years later, when the Central Troy Historic District was created and added to the Register, it was listed as a contributing property.

The exterior is a close copy of Trinity Church, New Haven, Connecticut (1813-1816), designed by the architect Ithiel Town in the Gothic revival style.

Today, the exterior of St Paul's is remarkably unchanged, but the interior underwent complete redesign in the 1890s.

Balconies had caused structural problems, and the Rector, Dr. Edgar Enos, convinced the church to fund a complete interior renovation by the Louis Comfort Tiffany Company.

As such it is a fully integrated interior design; only four such churches done by the Tiffany Company have survived intact, and St. Paul's is arguably the finest expression of this concept.

It is faced in limestone blocks laid in a random ashlar pattern with dressed pilasters at the corners.

The high ceiling is supported with wooden trusses; they and the clerestory screens are carved and decorated with gold-tone aluminum leaf.

It also shows the influence of 16th-century English churches and, in its rough surfacing and irregular masonry, a touch of the contemporary Picturesque styling.

The only significant difference between the two was their facing: Trinity used brown granite whereas St. Paul's used blue-gray limestone quarried in nearby Amsterdam.

In 1881, the construction of Martha House (to which a second story was added six years later), originally a residence for the nuns associated with the church, cost it the easternmost window on the northern profile.

These led to the major renovations to the interior early in the 1890s, after money was raised to fix structural problems from the original construction.