In the new century, the neighborhood's growth slowed down as it was nearly built out.
A few new houses were built, mostly architecturally sympathetic to their surroundings but experimenting slightly with their materials, such as local architect William Lee Woollett's brick houses with marble trim at 43 and 45 Ten Broeck Street in 1900.
At 66 First Street another brick and stone house went up, sympathetic with its much older neighbors.

The affluent families that had lived in the Ten Broeck area began moving to the newer neighborhoods in the city's undeveloped western sections, which offered larger houses and larger lots in the newer suburban style of living.
They rented the houses they left behind or sold them, with the result that many were subdivided into multiple units, making the Ten Broeck Triangle less exclusive than it had been for the previous 50 years.

This increase in density was reflected in the most significant construction of the 20th century's first decade.
St. Joseph's had housed its school in various other buildings, but finally had to construct one for the purpose.
The four-story brick edifice with stone trim completed in 1905 was the largest building in the western blocks of the future district.
Back on Ten Broeck Street, the church itself got a new spire in 1910.

The trend toward increasing density culminated in the construction of two apartment buildings, at 7–8 and 9–10 St. Joseph's Terrace, in 1914.
Both brick with stone trim, one three stories and the other four, they were the first buildings in the neighborhood designed as multiple dwellings.
Together with the nearby house at 3 St. Joseph's, a one-story brick building with marble trim and a Spanish-style pantile roof, built that same year, they are the latest-built contributing properties to the district.
In the new century, the neighborhood's growth slowed down as it was nearly built out. A few new houses were built, mostly architecturally sympathetic to their surroundings but experimenting slightly with their materials, such as local architect William Lee Woollett's brick houses with marble trim at 43 and 45 Ten Broeck Street in 1900. At 66 First Street another brick and stone house went up, sympathetic with its much older neighbors.
The affluent families that had lived in the Ten Broeck area began moving to the newer neighborhoods in the city's undeveloped western sections, which offered larger houses and larger lots in the newer suburban style of living. They rented the houses they left behind or sold them, with the result that many were subdivided into multiple units, making the Ten Broeck Triangle less exclusive than it had been for the previous 50 years.
This increase in density was reflected in the most significant construction of the 20th century's first decade. St. Joseph's had housed its school in various other buildings, but finally had to construct one for the purpose. The four-story brick edifice with stone trim completed in 1905 was the largest building in the western blocks of the future district. Back on Ten Broeck Street, the church itself got a new spire in 1910.
The trend toward increasing density culminated in the construction of two apartment buildings, at 7–8 and 9–10 St. Joseph's Terrace, in 1914. Both brick with stone trim, one three stories and the other four, they were the first buildings in the neighborhood designed as multiple dwellings. Together with the nearby house at 3 St. Joseph's, a one-story brick building with marble trim and a Spanish-style pantile roof, built that same year, they are the latest-built contributing properties to the district.
Arbor Hill Historic District–Ten Broeck Triangle