Hacienda de las Flores: How Moraga’s Estate Architecture Grew in Layers

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

Hacienda de las Flores is more complicated than a single house built in a single style. Its present identity developed through a modest early residence, a much larger private estate and later public use.

Looking at those layers gives the architecture a clearer story. Rooms, wings and outdoor spaces were added to support changing ambitions, rather than appearing together as one finished composition.

The beginning was a smaller, single-story house

The Moraga Historical Society’s researched history describes a 1916 Spanish ranch-style house associated with Alberta Higgins and Gertrude Mallette. Its original entrance occupied the space now known as the Mosaic Room.

That detail offers a way to read change from within a building. A room’s present name and use can conceal an earlier circulation pattern, including where someone first entered and how the house addressed the surrounding property.

The original house provided the foundation for later work, but it did not already contain the full arrangement subsequently associated with the Rheem estate.

The later estate changed both scale and movement

The historical society describes the Rheems adding upper floors to two wings and another wing at the rear. It identifies arched windows, ornamental ironwork and elaborate stairs among the changes, while noting surviving early timbers in the Fireside Room.

These additions changed more than the exterior outline. Extra levels required vertical circulation; new wings expanded the building’s reach across the site; and the retained older fabric continued inside a more elaborate house.

The result can be understood as an architectural accumulation. Some features express the early domestic building, while others belong to the estate’s subsequent expansion and entertaining program.

The pool pavilion organized a separate social world

The society attributes the 1938 pool cabana, now called the Pavilion, to Clarence Tantau. Its account describes a reception room, salon, guest and changing accommodation, a bar and an upstairs projection room.

That program made the pool setting a place to gather for an extended occasion. The supporting rooms mattered as much as the open water: guests could change, rest, socialize and watch a film within the same small complex.

Seen this way, the pavilion was a carefully equipped destination within the larger property. Its architecture helped separate outdoor recreation and entertainment from the everyday functions of the main house.

Public ownership introduced a different set of priorities

The town’s 2016 conceptual feasibility study traces the property’s transition through the Christian Brothers and the recreation authority to town ownership in 1977. It evaluates a roughly nine-acre community facility rather than the full historic estate.

The distinction matters when interpreting old plans or descriptions. The former estate’s extent and private household arrangements do not define the current public property or every present use.

The study also belongs to a particular planning moment. Its possible future concepts should be read as proposals from 2016, rather than as a list of completed improvements.

Read the buildings through the spaces between them

At the Hacienda, the architectural story includes approaches, patios and the relationship between the main building and pavilion. These connections explain how separate structures could participate in a shared occasion.

For a home comparison, the same observation is useful at a smaller scale: consider how living rooms, terraces and secondary structures actually connect, rather than counting each attractive feature in isolation.

Explore real estate and home for sale in Moraga and our property-setting comparison. Contact Diamond to compare architecture, outdoor space and the way a property supports daily life.

Sources checked October 28, 2026. The 2016 study is an archival planning document. Consult the town or current operator for facility access and event arrangements.