Mark O'Brien is an exceptional real estate broker who brings extensive experience and professionalism to the New York City real estate market. His deep knowledge of co-op properties and the Manhattan real estate landscape makes him an outstanding choice for buyers navigating the complex New York property scene. Throughout the co-op buying process, Mark demonstrates remarkable patience, expertise, and a relaxed approach that puts clients at ease. He is known for guiding buyers through the intricate co-op application and board interview process with skill and confidence.

Mark was great to work with. He has deep knowledge and helped guide us in our purchase. He helped us consider the pro and cons of various aspects of each property we viewed and ultimately we were very happy with our choice.

I am using Mark to sell my Upper West Side co-op and to help me purchase another co-op on the Lower East Side. I first met Mark about 3 weeks ago when looking online at co-ops on the Lower East Side. On a frigid Sunday afternoon we went to view 10 apartments. Mark answers all of my questions almost immediately, and I have many. We just started showing my apartment and by the end of the second week he'll have been here 5 times - 3 times showing it to individuals and 2 open houses. He is very easy to work with. I would highly recommend him.

My best friend Rachel had used Mark to help find her new home. After visiting Rachel’s new home, I was so impressed and excited for them that I decided to buy in NYC and of course I called Mark. Rachel had also renovated the home, and many of the contractors she used were recommended by Mark. I knew I wanted to take on a project, so going to Mark was a no brainer after seeing his work with Rachel. We are in the process of renovating now, and all is going well thus far!

Mark was very easygoing and helpful. He explained all of the intricacies of the home buying process and was there by our side the entire time. He helped us understand coop vs condo and closing cost involved for each. We had so many questions and he had answers and a network of people to help, he introduced us to a great real estate lawyer. He was very patient and understanding. Overall, it was a very smooth experience, and I could not recommend him enough!

Mark was a huge help in selling our house. Not only was he extremely communicative, he was also very friendly and made me and my wife very confident our house would be sold. Mark has a lot of building experience and was very helpful as well directing us to contractors and suppliers for a renovation project that turned out great. Mark always had solid input and a very deep network of real estate professionals. Thanks Mark!

I was having trouble selling my home, but then I found Mark. Within only a month, I had received 2 offers. I noticed other Brokers had difficulty showing potential buyers a clear vision for how to renovate a convert our foyer into more usable space. Mark was fantastic helping buyers understand cost, time frames and design, as Mark has experience building homes. Mark was the best Real Estate move I had made!

I had been looking for the right home for 6 months to no avail. A coworker of mine who had worked with Mark in the past recommended him to help find our home. After only a month Mark helped find our dream home! He then connected me with contractors to build a wall to create an additional bedroom and patch the wood floor. The contractor was great and Mark really facilitated the renovation. Wonderful experience!

Mark was very accommodating and helpful when we sold our home. He made improvements to our online listing and used different tools like SEO to garner more online traffic. Our property was on the market for 103 days before Mark, but after his improvements to the listing, it sold only 18 days later. We could not thank Mark enough!

After finding Mark on Zillow, the process of finding our dream home became seamless and worry-free. Mark scheduled all of the homes that we wanted to see and offered his own input and ideas on other listings. We finally found our dream house with the help of Mark, and we love living here now. Thanks Mark!

Mark is a very responsible agent and very easy to work with. He helps us a lot for our moving in process. He helped to coordinate for the walk through, contacted contractor for making closet and shades. He is very knowledgeable and responsible. I highly recommend him to our friends.

Mark is extremely knowledgeable when it comes to what is available on the market and went above and beyond what was expected. He searched for the best apartments that met my criteria and made sure each step of the process was as easy as possible. I highly recommend him.

I have been working with mark for 1.5 years now. He is very patient and helpful. Mark connected me with 2 mortgage bankers and helped guide me through the bank commitment process. His recommendations have been fantastic, and they also speak very highly of Mark.

After being recommended to Mark by a friend, I couldn’t be more thrilled of how the process unfolded. Mark was always available to address any questions I might have, and Mark was consistently communicative. I was very impressed by how smooth the process went.

I worked with Mark since 2005. We bought the house he built and after we moved in, he was always available to answer any questions or came right over if anything went wrong with the house. He is very personable yet also professional.

Mark was very patient with us as we changed our focus a few times. Navigated us through the difficult Co-op buying process in Manhattan. He has a relaxed personality and knows the market.

Mark helped me with buying my new apartment in the West Village and he also has a crew of contractors which was invaluable to me. He introduced me to Abel and together they helped me design and submit for approval before closing and the week of closing they started the work. I'm in LA often, and Mark managed the process for me. Can't say enough about his team.

LOVED working with Mark and his team. Mark is very knowledgeable about real estate from condos to coops and everything in between. We enjoyed viewing apartments with him as he always pointed out something we wouldn't have considered about the building, unit, etc. He was extremely helpful during the initial offer to contract negotiation and very hands-on during the coop application / board interview process. I'd work with Mark again and recommend him to friends and family.

I started working with Mark a few years ago and then for multiple reasons (including covid), stopped my search. When I started it up again last year, we picked up right where we left off and he quickly found me the perfect apartment. Mark has more local knowledge than almost anyone I've ever met in New York, and that knowledge went a long way in helping me find the right areas, avoid unexpected pitfalls, and ask the right questions. I highly recommend Mark for anyone looking for a place in NYC.

Mark is dedicated to you despite him being busy. He pays attention to detail and understand how to communicate the nuances of the buying process. Lucky to have found him somehow. Highly recommend.

Mark goes over and above. Large or small deals he is a true professional, with lots of heart. He was most helpful in guiding us through a process unusual to one not from the area. I would utilize Mark again without thinking twice.

Mark is an incredibly competent yet relaxed real estate professional. He was both super responsive as well as patient -- two important qualities for a broker to have! And he was able to minimize the stress of the home-buying process. I highly recommend him.

Mark was incredibly patient and easy going. When we first approached him, we had no idea what we were getting into. He listened to all our crazy ideas, and spend plenty of time showing us properties. As a New Yorker, he knows the market well and tried his best to educate us. When it was time for the closing, he helped us every step of the way. Mark and Courtney (his assistant) made the process less painful.

Mark was very patient with us as we changed our focus a few times. Navigated us through the difficult Co-op buying process in manhattan. He has a relaxed personality and knows the market.

As a first time buyer moving to NYC - Mark, his team and broad professional network made the process a very positive experience. We felt very fortunate to have found Mark - he listened to us, helped us navigate the NYC real estate market and provided valued guidance from start to finish! We are thrilled to be in our Chelsea apartment!

Mark and his associates helped us find our dream apartment in Lincoln Square. It was such a personable experience that we never encountered with a realtor. They were like family presenting us to our new home.

Mark helped me sell my Upper West Side apartment back in 2020 (in the middle of COVID). He was very knowledgeable and helpful through the entire process. I would recommend working with him.

Fantastic!

Mark took the time to understand my needs. He and his team have excellent knowledge of the market. He showed me a variety of options in Manhattan. My new neighborhood is ideal for my lifestyle. I'd recommend Mark to friends and family without reservation

Mark was wonderful helping us navigate finding our Brooklyn home. We spent months going through different options together and ultimately decided on a place we are very happy to call home. Really appreciated his measured diligence and patience throughout the process. Would recommend him and his team to anyone looking to navigate the NYC real estate market.

Mark and his team are fantastic. They knew how to handle my whole purchase of an apartment in Chelsea very smoothly. I love my new place

Mark and his team helped us with buying our NYC coop and we couldn't be happier with the result. Mark was knowledgeable, patient, and always available to help us find exactly what we were looking for in a location we wanted. They guided us through scary coop approval process with knowledge and skill, and helped us find a perfect place. We have recommended Mark to a few friends and family without reservation and will continue to do us. Ideal agent for your NYC needs!

Mark and his team were great to work with. Responsive, professional and supportive. Buying a place in NYC is quite a process, and I felt like they were on my team each step of the way. It was nice to have that relationship as a busy tech professional with limited time, like many New Yorkers. Besides supporting people with home purchases, he renovates historic town houses around the city and is passionate about real estate.

Moving to New York, Mark and his team helped me navigate the NYC real estate market and find the perfect neighborhood for me. My new apartment is in a great part of town and the rooftop views are amazing! I am so happy in my new home!

Mark and his team are very competent. They made the buying experience quite easy despite the fact that I never met him in person. Very easygoing. He's lived in NY nearly all of his life and it shows. Recommend him for your real estate needs.

Mark was very helpful when it came to answering any questions or concerns I had. As a first time home buyer he took every action possible to ensure I was comfortable through the entire process. I could not be happier with how him and his team handled everything. I highly recommend to anybody looking for their next home!

Mark is wonderful to work with. He takes time to understand your requirements and will do his best to find the appropriate solution. He gives all the relevant information on time and will go the extra mile to find additional pieces of data required for you to make a decision. He is fast, punctual and a pleasure to be with. I highly recommend him for your real estate needs.

Mark and his team helped me navigate the complex and often fast-moving New York City real estate market. He is super easy to work with. I am so happy in my West Village home.

Mark is a pleasure to work with. He is dedicated, compassionate and always available. His expertise in the New York market is unmatched. Thanks again Mark!

My wife and I are fans of Mark's work. This is our first home together, and we couldn't be more excited about the future! From the moment we set our eyes on the property, we were captivated by the build quality, thoughtfully designed layout, and overall aesthetic excellence. It's not often one encounters the "perfect" home, precisely in the ideal location, but we consider ourselves incredibly fortunate to have found it! Once again, thank you for your outstanding work, and we wholeheartedly recommend Mark O'Brien's homes to anyone seeking a remarkable and unforgettable living experience.

Brian is amazing. He was my listing agent for our condo in Williamsburg. Right from the get-go, he gave us advice that was spot-on. We sold with multiple offers on the table and at a price that was a “reach goal” for us. He kept us in the loop at all times, helped us tremendously while I was an “absentee” owner of sorts. I had inadvertently left behind some materials in the apt - he was kind enough to clear those out for us.. since we didn’t live in the apt anymore. He is just.. brilliant.. our friend Alex Salt had recommended and trusted him with our apt and Brian went above and beyond.

Brian and his team are fantastic. We worked with him both when we signed our lease at 420 Kent Ave and later when we had to reassign our lease due to COVID-19 fallout. He is responsive, friendly, and professional, and has a wealth of knowledge about Brooklyn and the NYC real estate market. I would 100% work with Brian again and recommend him and his team to anyone looking at real estate in Brooklyn. You will be in very good hands!

After living in the same loft for more than a decade we unexpectedly found ourselves searching for a new home a year into the pandemic when our landlord decided to sell the building. We found Brian via a listing he posted. When we arrived at the building he showed us the original listing but was also able to get us into a few more apartments that hadn't hit the market yet. They were still in the renovation stage but we could see they were gems. We quickly nabbed one of the pre-renovated units because of its amazing light, high ceilings, and large floor plan. Brian made the lease process with the management company a smooth transaction. We've been pr...

Brian is amazing. He was my listing agent for our condo in Williamsburg. Right from the get-go, he gave us spot-on advice. We sold with multiple offers on the table and at a price that was a “reach goal” for us. He kept us in the loop at all times and helped us tremendously while I was an “absentee” owner of sorts. I had inadvertently left behind some materials in the apt - he was kind enough to clear those out for us.. since we didn’t live in the apt anymore. He is just.. brilliant.. our friend Alex Salt had recommended and trusted him with our apartment and Brian went above and beyond. LOVE the kid.

Brian facilitated a sublease for me. He made the process a breeze. What could have been a nightmare was effortless. I was so impressed with my experience with him that I intend on using him as my agent to buy. Corcoran is lucky to have him.

Brian helped me with the condo rental. He is extremely reliable and professional. He is friendly and hard-working and was able to help me in a few weeks. Whenever I have a question, I can email him or call him and Brain is always there for me. Highly recommended.

Brian helped us find a replacement tenant to assign our lease when we needed to leave our apartment early. Extremely knowledgeable, responsive, and pleasant to work with. And, of course, got the apartment rented out quickly!

Brian represented us as a buyer's agent. We were first-time home buyers looking to purchase a property in Williamsburg or other neighborhoods in Brooklyn. There was just an overwhelming amount of details we needed to learn and Brian made everything so clear and easy. Throughout the process, he was always quick to respond, provided professional insights into each property we were interested in, and helped us along the way. We enjoyed working with Brian and can certainly recommend him to anyone!

Brian was my rental agent when I was looking to move to Greenpoint, Brooklyn and he was an absolute pleasure to work with! Greenpoint is a very desirable market and I was nervous that I'd be spending several weeks viewing apartments before finding the one I wanted to call home. As it turns out, I met Brian on the first day I was viewing places and he showed me the apartment that is now my home! Brian was very knowledgeable of the area and super helpful during my application process. He even helped me negotiate a great deal. I highly recommend working with him if you have the opportunity.

Working with Brian was a blessing - the smoothest process I have experienced in my many real estate dealings over the years. Brian listened, and heard what I wanted! Went to work & delivered. Always relevant, concise, to the point, HONEST. Plain-speaking and no-nonsense or a waste of anybody's time. I'll reach out to Brian next time I'm looking to sell/buy in NY Metro.