A major mixed-use infill development is coming to Lower Downtown Denver, and a big gap in LoDo’s urban fabric will be healed in the process.

Colorado-based McWhinney, along with partner Grand American, is planning an office, residential, and retail project on the block bounded by Wazee, 19th, Blake, and 18th streets. Named “Z Block” to highlight the project’s location along LoDo’s fun-sounding Wazee Street, the mixed-use development will bring a substantial infusion of activity to the heart of Lower Downtown and replace nearly a half-block of surface parking with buildings that reinforce the historic district’s traditional urban form. Here’s a GoogleEarth aerial photo where I’ve outlined the project site in yellow:

The image above shows Z Block’s key location between Denver Union Station and Coors Field, as well as its T-shaped footprint that covers not only the full half-block along Wazee, but a portion of the block’s Blake Street frontage as well. The white-roofed building in the image above on the Wazee side of the block is an old one-story warehouse (used for parking cars!) and adjacent to it at 18th and the alley is a small three-story office building. Both of these buildings are non-contributing structures to the Lower Downtown Denver Historic District and will be removed. Here’s a Google Street View image showing these two structures.

Additionally, two one-story buildings in the center of the Blake Street side of the block are also non-contributing structures to the historic district and will be replaced by new construction. Here’s a Google Street View photo of these two buildings:

On the Wazee side, Z Block will feature a 6-story, 260,000 square foot office building with office space on floors 2 through 6, and a mix of office, restaurant/retail, and lobby spaces on the ground-floor. On the Blake Street side, the project will include 70 apartment units in a 6-story structure with residential and retail spaces on the ground floor. Z Block also includes three levels of underground parking with a total of 425 spaces, allocated as follows: 260 spaces for office users, 70 spaces for residential users, 83 spaces for existing tenants on the block, and 12 additional spaces. Here’s a ground-floor site plan (all the following images are courtesy of McWhinney and their project architect, Shears Adkins Rockmore):

The image below shows how the project will span across the alley, connecting the office and residential portions. The “invisible” building in the center foreground is the historic building where the Celtic Tavern is at 18th and Blake (18th Street is on the left and Blake Street is on the right). The new structure on the right side of the image is the residential component facing Blake Street, and behind and to the left is the block-long office building facing Wazee. The top five floors of the office building on the 18th Street side has been cut away to illustrate the project’s mid-block connections, ground-floor uses and street-level passageways.

Z Block viewed from 19th and Wazee looking south:

Z Block viewed from 18th and Wazee looking east:

The residential part of Z Block on Blake Street:

According to McWhinney, Z Block is scheduled to break ground in October or November 2014 with an 18-month construction time frame.