Garrison Hill Group operates at the intersection of capital, operations, design, and construction. We bring owner-side leadership to every phase of a project. From feasibility through final delivery, we protect your budget, your schedule, and your outcome.
Every project has multiple stakeholders. Each one has their own interests, their own pressures, and their own agenda. Owners and tenants are often the least protected of all. Garrison Hill Group exists to change that. We advocate for you at every phase, every decision, from inception to completion.
A comprehensive range of owner-side advisory and execution services, structured around your specific needs.
We have worked in the field, run jobs, and managed millions of square feet for one of New York City's largest real estate firms. We know every seat at the table. We represent your interests from the first conversation to the final walkthrough, keeping everyone honest and accountable along the way.
Before the design team is set. Before the budget is locked. Before the lease is signed. We get involved early so the decisions that matter most are made with the right guidance.
Multiple properties. Multiple moving parts. One trusted advisor across every asset. We bring the same level of care, accountability, and leadership to every property in your portfolio.
From site evaluation to design team selection to feasibility, we help owners navigate the earliest and most critical stages of a development project.
The landlord has a team protecting their interests. Lease negotiations, tenant improvement dollars, scope division, and landlord obligations. We make sure you know what you have, what you are owed, and how to protect your interests.
Hands-on project oversight from preconstruction through closeout. Budget control, schedule management, and vendor accountability on every job no matter the size.
Teamwork and collaboration are the foundation of every successful project. We identify misalignment early across owners, design teams, contractors, and landlords and resolve it before it costs you time and money.
What looks good on paper does not always translate to the field. We make sure the design, the budget, and the reality of construction are all aligned so nothing gets lost between the drawing and the job site.
Sometimes that means preventing cost overruns. Sometimes it means having an honest conversation about whether the numbers actually work before you commit. Unrealistic budgets and unrealistic schedules are two of the most common and most expensive problems in construction. We identify both early and give you a clear picture before it is too late to change course.
Clear communication and transparent reporting are the foundation of every engagement. We hold architects, engineers, contractors, and consultants accountable. We hold ourselves accountable. And when the moment calls for it, we will tell our clients the same. Delays in decision making are one of the most overlooked causes of cost overruns and schedule slippage. Sometimes the most valuable thing we can do is let you know that the next move is yours.
Most people in this industry know one part of the process. They know the field or they know the boardroom. They know the contractor side or the owner side. Rarely both. Rarely all of it. Dermot O'Sullivan has spent two decades doing all of it. He started his career in the trades, working as a carpenter and learning construction from the ground up. He moved into superintendent and project management roles on the general contractor side, where he learned what it actually takes to deliver a project in the field. From there he made the move to the owner's side, spending nearly a decade overseeing some of the most complex commercial real estate projects in New York City. Throughout every role, one thing remained constant. Dermot found himself in leadership positions not because he sought the title but because of how he works. With honesty. With integrity. Owning every decision, every outcome, and every lesson along the way. Garrison Hill Group was built on those same values. Owners deserve an advisor who has actually done the work, who will tell them the truth, and who genuinely cares about the outcome. That is what GHG is. That is what Dermot brings to every engagement.
If you have a project, an idea, or just a question you do not know who to ask, reach out.