St Simon's is a late Victorian church building with attached hall (1879 - 1886), designed by Sir Arthur Blomfield. The first stone was laid in 1878, and the first service was conducted in 1880. The church is set in the midst of terraced housing a few hundred yards south of Shepherds Bush Green. It has an imposing spire and clock tower and a small garden space. The chancel, parish hall (East hall) and spire were completed in 1886. The tower and spire start from a pentagonal base and become hexagonal above the aisle roof. Tower and spire are polychrome and have strong horizontal bands of stonework. One of the most striking pieces of stained glass in the church is the east window. This is above the altar, visible as you enter the church, and was put in place in 1903 to commemorate the first vicar, the Reverend Robert Handcock. The style is rich and colourful (like that of Clayton and Bell).
The c 1865 organ of Dunblane cathedral was purchased second hand in 1893 and bears the words "Rebuilt by Eustace Ingram, London 1893". Most of the music in the church is played on keyboard and guitars, with the organ regularly used during Sunday morning communion services. There are stencilled ornaments on the east wall and to the north and south of the sanctuary. The wood is decorated with simple Gothic flower patterns and there are little arches featuring Christ, Moses and St Simon. This is in the simple 1870s style associated with churches designed by Clayton and Bell, Butterfield or Scott.