First
Unitarian's congregation hired the firm of
Ferry & Clas of Milwaukee to design their new church building, and
Ferry himself led the design - in reserved Gothic Revival style. Most walls are rock-faced
Bedford limestone, rising to steep gable roofs with dormers. The general floor-plan is L-shaped, with a tower rising from one leg of the L.[3]
Inside, the auditorium has a
hammerbeam ceiling resting on carved stone
corbels. The
chancel contains an organ, a
pulpit, and a carved oak
sedilia. The windows have abstract designs.[3]
The church is little changed from when it was built. First Unitarian was placed on the NRHP for its architectural significance, but it is also the oldest Unitarian church building in Milwaukee.[3]