Independence House during their balcony repair project in 2015. The Bronx co-op saved over half a million dollars after a peer review conducted by RAND.
Independence House’s 36 balconies were in bad shape. Water had seeped into the concrete of the balconies for years, causing damage to the reinforcing bars and supporting steel I-beams. The undersides of the balconies were spalling (flaking and chipping) as well. The board of the seven-story, 51-unit co-op at 2711 Henry Hudson Parkway in the Spuyten Duyvil section of the Bronx had an engineering study done which claimed the balconies were designed incorrectly. A design-build contractor was hired who used a jackhammer to remove the spalling and then recommended a complete replacement of all the balconies at an estimated cost of $1.2 million.
Repairs ranged from minor surface work to new concrete and rebar installation, and included a new water resistant membrane system.
The board decided it was time for a second opinion and hired RAND to conduct a peer review. RAND conducted probes of the exterior walls and balconies with Xinos Construction and discovered that the original design and construction were not faulty as claimed by the first engineer. In addition, we found that the design-build contractor had used an improper equipment to remove the spalling and had created additional damage, including a hole in one of the balconies. Despite this damage, we determined from our findings that balconies could be repaired and were not in need of a complete replacement.
The board hired RAND and Structural Preservation Systems to start construction in 2014. The repair program was completed in 2016 and ended up costing about half the original estimated cost to replace the balconies, which goes to show, getting a second opinion can really pay off!
For more on this project, see the article in Habitat magazine.
Christine Hobson, PE, is Senior Structural Engineer at RAND.
