It can be done—Liberty Property Trust took 10 existing buildings in Philadelphia, made them bastions of sustainability, and came in under budget. VP Fred Dougherty, director of sustainability Marla Thalheimer, and sustainability analyst Jonathan Payne tell us their half of their $4.2M PECO/DOE Smart Grid project was funded by a federal grant, and they also received $189k of utility rebates. The team picked buildings of various ages and existing sustainability levels and did HVAC and lighting overhauls, a thorough retrocommissioning, and they put in place demand response strategies.
LPT’s achievements so far (and they’re still catching and resolving inefficiencies):
• Average Energy Star cert raised from 63 to 79
• Occupancy increased from 82% in 2010 to 96% this year (the improving economy helped, but don’t underestimate the power of marketing a high-tech building)
• 15% weather-normalized energy reduction
• Cost savings of $0.92 per occupied SF
Overall, LPT is projecting a roughly three-year payback period (including rebates and demand response). HVAC was the biggest bang for the buck (and tenants love it)—it cost $1.65/SF but has lowered opex $0.30/SF and accounted for 53% of the total energy reduction. On the other hand, lighting retrofit costs $3.73/SF, is saving $0.25/SF, and has raised TI and not been as well-received by tenants. (It's worth it for long-term holds, though.) But above all things, Fred has been amazed at the value of retrocommissioning. It cost $0.57/SF but unearthed 800 different inefficiencies, including the discovery that every single VAV box in LPT’s portfolio was out of calibration.
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