In the heart of Manhattan, where competition is relentless and construction timelines are measured with the precision of financial markets, Sinclair Construction has carved out an extraordinary trajectory. From its Broadway office, the company has delivered numerous successful construction projects in just two years, building up a remarkably striking portfolio for a company so new. Yet to founder Jason Sinclair, this rapid growth is simply the product of deep experience, trusted relationships, and a family lineage steeped in New York City construction.
Sinclair Construction opened its doors backed not by speculation or venture capital but by decades of accumulated knowledge. Jason spent nearly fifteen years working for two major construction companies in the city, gaining not only the project experience required to build at scale, but also something even more valuable: an understanding of how to thrive in one of the most challenging urban environments in the world. He had already overseen several million square feet of new construction and major commercial renovations before establishing the company, and his network stretched across developers, architects, and subcontractors familiar with the unpredictable reality of New York jobsites.
The company’s breakthrough came with a project in Greenwich Village that would set the tone for everything that followed. Jason remembers the moment clearly: a client entrusted him with a 30,000-square-foot dormitory conversion at 118 West 13th Street, transforming it into eight luxury condominiums. “It took about 20 months to do the project,” he recalls. “And during that, we picked up two new clients that we are currently in construction with.”
That first assignment stamped Sinclair Construction as a company capable of handling complex adaptive-reuse projects in heritage neighborhoods. It also delivered a wave of media coverage that introduced Sinclair to the market in its earliest days. Built in the 1930s, the original structure had served generations of young women arriving in the city for new opportunities. Sinclair’s team preserved or replicated key historical elements, including custom millwork, while modernizing the building to meet today’s expectations for luxury living. The project set a standard that would quickly become the company’s calling card.
Word of mouth did the rest. As Jason explains, those early projects led directly to two major clients who remain with the firm today. One is RJ Capital Holdings, which brought Sinclair Construction a flagship assignment: a 241-unit condominium development currently rising along 70-28 Grand Central Parkway. Designed by SLCE Architects, the 260,000-square-foot, 13-story building is on track for completion in mid-2027 and includes a full amenity suite with a pool and gym. The project also features more than 120 enclosed parking spaces, nearly 90 outdoor spaces, and extensive bicycle storage. The lot’s vacant condition allowed Sinclair to build with freedom and execute a clean, efficient construction sequence.
The second major client from that early period is Astral Development, which has entrusted Sinclair with another intricate conversion: turning a SoHo office building into a set of luxury residential units. The six-story building at 40 Wooster Street will soon include ground-floor retail, several two-bedroom apartments, and a dramatic duplex penthouse across the upper floors, complete with a private pool.
While Jason’s expertise forms the technical backbone of the organization, the company’s growth has also been shaped by family. His father, Tom Sinclair, who had semi-retired from the industry, agreed to return when Jason asked for help; a decision that quickly became essential. “The business was growing so quickly and rapidly,” Tom recalls. “We’ve got some quality developers come our way. We appreciate the heck out of those people, and I think in turn, they feel the same way about us.”
“We’ve had some quality developers come our way. We appreciate the heck out of those people, and I think in turn, they feel the same way about us.”
This generational perspective, spanning more than 40 years, is a key competitive advantage. Tom explains that having lived through cycles of New York development gives the company a clarity many younger firms lack. “We bring that to every client we meet, and we can set up a job to avoid the mistakes that other people are still doing with the budgeting, with the scheduling, with the logistics for a job, we’re focused.” With New York’s complex regulations, aging buildings, and dense neighborhoods, that ability to anticipate issues is invaluable.
As the company expanded, the team grew alongside it. Jason and Tom often joke that the company “doubled to two employees” the day Tom agreed to join. In 2024, they had a crew of six. By the end of 2025, the company had grown to almost 20 employees, with senior leaders including controller Matt Richardson providing financial and operational structure. Still, the company is careful not to scale too fast. Sinclair Construction prizes a lean, responsive model where clients maintain direct access to decision-makers. “Sometimes problems cannot be solved with a bunch of people,” Jason notes. “Efficiencies, new technologies and good communication often can address the underlying issues.”
That mindset informs every aspect of their client relationships. Before construction begins, Sinclair brings clients into the planning process, walking them through the challenges and anticipated solutions in full detail. During the build, the team communicates adjustments immediately, ensuring that changes in scope, schedule, or logistics never become surprises. This transparency is part of the firm’s strategy for long-term partnership, the backbone of its fast expansion.
Much of Sinclair Construction’s work focuses on the residential sector, particularly high-end condominiums and adaptive conversions. Yet their projects also extend into mixed-use buildings, parking structures, and developments where ground-floor retail sits beneath housing; a typology increasingly common as the city rebalances post-pandemic. That mix is deliberate: it not only reflects market demand but also aligns with the company’s strengths in tight-site logistics and premium finishes.
The firm’s early success has placed it squarely within some of New York’s most dynamic development conversations. Its combination of urban construction expertise, generational knowledge, and flexible project execution has made it a trusted partner for developers working at multiple scales. And as new policies and market forces push more office-to-residential conversions, Sinclair’s experience in building within historic, occupied, or highly constrained sites positions it well for the next phase of citywide redevelopment.
For Jason and Tom, however, growth is not the only goal. The aim is sustainable expansion; a business that maintains quality and access while delivering large, complex projects across the city. The words they return to are the ones that shaped their first breakthroughs: trust, transparency, and the confidence to deliver under any conditions. Their clients, they say, continue to come back because they know exactly what Sinclair Construction stands for.
Small enough for clients to reach the principals directly, experienced enough to build some of the city’s most intricate projects, and agile enough to adapt to New York’s shifting landscape, Sinclair Construction has established itself not only as a newcomer with momentum, but as a company built for the long haul. As their portfolio grows, the through-line remains clear: generational knowledge, rigorous planning, and a commitment to doing things the right way the first time.
With strong demand, expanding partnerships, and a steady pipeline of work, Sinclair Construction is poised to shape the city’s next chapter, one carefully executed project at a time.
