Courtyard Renovation – Union Square Condominium Building

Title: Courtyard Renovation – Union Square Condominium Building

Award Category: Waterproofing

Project Address/Location

333 West Hubbard Street

Chicago, Illinois 60654
United States

Submitted By: Charlie Sietmann

Company Info

Building Technology Consultants, Inc.

1845 East Rand Road
Suite L-100
Arlington Heights, IL 60004
United States

847-454-8823

[email protected]

Project Description and Background: The Union Square Condominium Association consists of a 5-story low-rise building constructed in 1998, as well as a 10-story high-rise building converted from an existing factory at the same time. During that conversion, 4 stories were added to the existing 6-story factory that was originally constructed in 1918 and later expanded in 1938 and 1946. The original factory portion of the building is a concrete-framed structure with solid brick masonry exterior walls. The exterior walls also include terra cotta window sills, window heads, and parapet coping caps. The exterior walls of the 5-story low-rise building consist of a brick masonry cavity wall with concrete masonry unit backup. Below the 2 buildings is a parking garage, with an approximately 11,000 square feet courtyard located above the garage and between the 2 buildings. The lower-level garage is accessed via a ramp on the west side of the high-rise building. The courtyard originally consisted of a concrete topping over waterproofing and a structural concrete and steel deck. Within the courtyard are several planters, various landscaping, and a dog run. Ongoing water leakage had been experienced in the parking garage below the courtyard. In addition, significant deterioration of the concrete topping existed throughout the courtyard. Given its age and level of deterioration, the Association desired improved aesthetics and more usable common area amenity spaces, but most importantly a leak-free waterproofing system. Building Technology Consultants, Inc. (BTC) was retained due to their long history with the building and owner’s representative. BTC contracted services were to provide consulting services for the new waterproofing system, including performing a pre-design evaluation, design services, bidding assistance, and construction phase services. JRA Landscape Architecture, PLLC (JRA) was also added to the project team to provide support for the design of overburden, landscaping, irrigation, and furniture.

Scope: The Association retained BTC and JRA to provide specialized expertise in developing repair design documents, and overseeing construction to ensure long-term performance of the new assemblies. BTC’s involvement was critical given the complex interface of courtyard waterproofing, landscaping, masonry, and pedestrian elements. BTC began with an extensive evaluation of existing conditions, including exploratory openings. Investigations revealed that the original waterproofing had failed at multiple transitions, allowing water to migrate into the parking garage below. Based on the findings, the consultant developed a comprehensive repair strategy, including detailed design drawings and specifications for replacement assemblies. The scope of work included the complete removal of the existing courtyard concrete topping and waterproofing system, followed by substrate preparation and installation of a new hot-applied rubberized asphalt waterproofing system. This system was selected for its proven long-term performance, seamless application, and ability to withstand the loading of new hardscape and landscaping. The installation included a bituminous setting bed and a new brick paver system. At the ADA ramp and stairs to the high-rise building, and in the breezeway between the 2 buildings, the design incorporated a breathable, fluid-applied waterproofing membrane. This product was chosen to allow for vapor permeability while providing durable protection against liquid water ingress. The breathable system was particularly important in these areas, where trapped moisture from concrete over metal deck could otherwise lead to blistering or premature failure of traditional non-breathable coatings. In addition, BTC identified deficiencies at the base of the masonry walls where existing flashing terminations were too low and did not allow for sufficient heights for the waterproofing flashing below the through-wall flashing. To address this, the project included installation of new through-wall flashing systems at the masonry-to-plaza interface. These assemblies incorporated stainless steel flashing receiver, to properly divert water away from the wall base and integrate with the horizontal waterproofing below. BTC played an active role throughout construction, providing submittal review, mock-up evaluations, and on-site quality assurance observations to ensure continuity of flashing details and compliance with design specifications. BTC’s presence helped the project team address unforeseen conditions, such as localized substrate repairs, and ensured that transitions between systems were executed without gaps in protection. The completed project delivered a fully renewed courtyard, with robust waterproofing protection at both horizontal and vertical interfaces. The renovation also enhanced the courtyard’s function and appearance, providing an improved outdoor amenity space for building occupants.

Solution: Slope and drainage were important and difficult hurdles due to height limitations that were dictated by the existing entrance stairs and ADA ramp, as well as the existing door thresholds. Although raising the through-wall flashing allowed for improved flashing and overburden heights, additional drains were necessary in various locations to improve drainage. Various methods for sloping of the new system were considered, including a sand setting bed and a bituminous setting bed. A sand setting bed would create a flexible, unbonded system that would have been easier to install and maintain, but would require even more careful drainage design and ongoing upkeep. The bituminous setting bed was ultimately selected since it created a rigid, bonded system with better water resistance and dimensional stability in high-use areas. New planters throughout the courtyard also required drainage. New 2 stage drains were installed in each planter. The drains were plumbed to the existing courtyard drainage system in the garage below. In addition, at each planter, an irrigation system and lighting system were installed. Penetrations through the waterproofing were detailed with a PMMA flashing.

Value: BTC’s expertise, combined with the collaborative effort of the project team, ensured that the project achieved lasting performance, cost efficiency, and enhanced value for the Association. By engaging an IIBEC member, the project benefited from the latest industry knowledge, adherence to best practices, and a commitment to performance-based solutions. This professional affiliation reassured the Association that decisions were guided by long-term durability, building science, and industry standards—not by short-term cost or manufacturer preference.

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