The community continued to grow in the early 20th century. A school was built, and the Brentwood Citizens’ Association formed in 1903, a Methodist church was constructed in 1904, a fire department was started in 1905, and was formed in 1903. Kerosene street lamps were added in 1917, and electric lights were installed in 1920. When incorporated, the town included the southerly part of the Holladay Addition, the Brentwood Company subdivision, and two smaller additions. The houses built during this time consisted of small frame bungalows. Growth continued through the 1940s and 1950s, fueled by an influx of government workers. In the 1950s, many older homes were replaced and empty lots were filled with small cottages and ranch houses.