Otawhao is a large single storey country homestead, built in the Victorian eclectic style. It was built from 1898 onwards, and remains substantially in its original form. The house has a somewhat confused exterior design, including a combination of shiplapped, rusticated and exterior framed weatherboards. The interior of the house includes a fine panelled octagonal entrance hall. There is extensive use of native timber for ceilings and wall panellings. The Buildings Officer considers the interior features have been handled well, but are not unique in comparison with other homesteads of the same era.

The original owner, T F Fountaine, was closely associated with the founding and development of Woodville. His obituary states that he was regarded as one of the founders of Woodville, and during his lifetime he gifted to Woodville a reserve in the town centre opened in 1896 and known as Fountaine Square. He is said to have been qualified as an architect, surveyor and structural engineer, and involved in bridge and road making around Woodville. It is believed by the Fountaine family that he designed Otawhao, and his initials appear in a stained glass window above the entrance, but the pencil sketch plans of the house do not bear his signature to confirm this.