A sprawling USPS operations facility that has anchored a corner of Windsor's Griffin Road business park since 1990 is now on the market, even as the United States Postal Service continues to run day-to-day operations there under a long-term lease. The 67,364-square-foot building at 6 Griffin Road North sits on 5.77 acres and is being offered for immediate sale while fully occupied by the agency.
Marcus & Millichap is handling the listing, with the Hartford Courant reporting that brokers Harrison Klein and Chez Eider, working alongside John Krueger, are marketing the property exclusively on behalf of a New York City-based investment firm. According to ConnectCRE, the building was constructed in 1980 and functions as an administrative facility running operations for much of the Northeast. Eider told the outlet that the property's draw lies in its track record: “The appeal here is the continuity of the tenancy and USPS's continued commitment to this location.”
That commitment was reaffirmed recently. USPS entered an early lease extension in December 2025, and as part of that deal the owner will complete more than $300,000 in building renovations, per the listing from Marcus & Millichap. The two-story building is split into two wings and includes 257 private parking spaces and a single elevator, the same report notes.
A Regional Hub With Consolidated Staff
The facility isn't just a mail-sorting outpost. Per the Hartford Courant, USPS has consolidated personnel from other regional facilities into the building, including legal department personnel, reinforcing its role as a Northeast administrative center. The business park surrounding it also counts The Hartford and Cigna among its nearby tenants, according to the same report.
Marcus & Millichap is marketing a second property nearby too: 2 Waterside Place, an 88,153-square-foot building in a waterfront setting within the same business park, which the Courant reports is 75% occupied.
Office Park Reinvents Itself as Apartments Take Over
The USPS building's sale comes as Windsor's broader office landscape undergoes a dramatic shift. Klein told the Hartford Courant that planned office-to-residential conversions in the area are expected to add more than 300 apartments, reshaping the park into what he described as a live-work community even as it reduces the overall supply of office space.
Separately, the Marcus & Millichap listing for the USPS facility points to redevelopment across several buildings in the park expected to create more than 200 multifamily units, while a different Marcus & Millichap listing for the nearby office-auction property states the park has approved plans for over 350 new multifamily residential units — figures that may reflect different project scopes rather than a single tally. Windsor has also pursued new zoning intended to allow widespread conversions of vacant office space to residential and potentially industrial uses, according to the listing.
The Numbers Behind Windsor's Office Exodus
The trend is backed by hard data. A Windsor study found that about 60% of office square footage in the Day Hill Corporate Area was listed as available for lease or sale, according to the Hartford Courant. The district's office properties contributed about 36% of its total assessed value in 2019, but that share had slipped to just 23% by 2024, the same report found. Windsor's economic development director attributed much of the shift to the pandemic, telling the paper, “The pandemic accelerated changes to the commercial office market.”
Developers have moved quickly to capitalize. Brady Sullivan, a Manchester, New Hampshire-based company, proposed converting Buildings 4 and 8 along Griffin Road into 96 rental apartments, with 48 units planned for each building, the Courant reported. The same developer paid $3.9 million for two other Windsor office buildings it plans to turn into 171 apartments, according to Hartford Business Journal.
Windsor's Town Planning and Zoning Commission has already signed off on some of these projects. The commission approved a conversion of 7 Waterside Crossing into 57 apartments on Sept. 9, breaking down into 33 two-bedroom units, 14 one-bedroom units and 10 three-bedroom units, per Hartford Business Journal. Nearby, conversions at 1 and 3 Waterside Crossing into a combined 171 apartments were already underway, with the outlet noting that interior renovations and site work were in progress.
For now, the USPS facility stands as one of the park's few fully leased, fully operational holdouts amid that wave of residential change — a steady government tenant in a business park that is rapidly becoming something else entirely.
