One of the most historic buildings in Tempe will be revived and given a glass-enclosed addition, according to plans drawn up by architects for the dormant Hayden Flour Mill site.

VIDEO: Historic Hayden Flour Mill would rise again

Tempe-based Avenue Communities, developer of the property, and its architecture firm, Substance Design Consortium, have produced renderings that show the mill building and its separate iconic silo structure retained in their existing form but with a five-story glass office building in between and wrapped on top on the mill.

Machinery once used to grind flour inside the mill will be displayed vertically at the northeast corner of the addition, visible through glass from a plaza below. Also the machinery would be visible from a glass-enclosed elevator, according to the plans, which have been approved by the Tempe Historic Preservation Commission.

The 1918 mill building - not to be confused with the separate silo structure that was added in 1951 - will contain a restaurant, retail stores and offices.

Archaeological structures, including an intact stone archway that straddled a canal once providing water power for the mill, will be preserved beneath the glassy addition.

“What makes this project unique is for the old and the new to interact with each other,” said architect Jose Pombo.

Also part of the redevelopment project is a single-story building fronting on Mill Avenue that will contain boutique retail stores. And a winery will be housed in a new structure at the southwest corner of the site.

The taller silos and grain elevator will not be touched initially, but they could be modified for other uses in a second phase, said Rick Labonte, project manager for Avenue Communities. He declined to say what options the company is considering but said Avenue Communities has been looking at silo-reuse projects in Akron, Ohio and Denver in which the structures were converted into hotel rooms and condos.

“We want to make sure we understand what is in front of us,” he said.

Labonte called the site “a tremendous opportunity” for his company because “the historic amenities are about a rich as you can find in the Valley.”

The entire project, including both phases, is expected to cost $500 million.

Under the firm’s development agreement with the city, construction is scheduled to begin by March 2008, and the first phase will open in late 2009.

Mayor Hugh Hallman, who has been deeply involved in preserving the Hayden buildings, said the design meets the desire of the historic preservation commission for an addition that is distinguishable from the historic mill, making it clear what is historic and what is modern while fitting well together.

“I’m excited. I’m eager to get it under way,” he said.

Hallman believes a boutique hotel will be the best use for the silo structure. Because of its narrow depth, it probably would need an addition on the back similar to the addition to the mill building, he said.

History of the Hayden Flour Mill

119 S. Mill Avenue, Tempe

The oldest continuously used industrial site in the Salt River Valley

1874 - Charles T. Hayden builds first mill on the site; along with store, warehouse, blacksmith shop and ferry it becomes the trade center of the south side of the Salt River.

1895 - First mill, made of adobe, burns; second mill built, also made of adobe

1917 - Second mill burns

1918 - Existing four-story mill is built, the first cast-in-place concrete building in Tempe

1924 - Salt River Project extends electricity to the mill, replacing the water power that operated the mill for half a century

1951 - 150-foot tall concrete grain elevator with seven silos is added, providing storage capacity for 18 million pounds of grain

1981 - Hayden family sells facility to Bay State Milling Co., which expands production

1998 - Milling operations cease

2002 - Three-alarm fire burns but does not destroy the vacant mill building because of its fire-resistant construction

2006 - Archeological studies reveal foundations, other old structures connected with milling operations

2006 - Avenue Communities selected Tempe to redevelop site

Source: Tempe