Karen Kostiw
Real Estate Professional
Licensed Real Estate Salesperson
Karen Kostiw's extensive background in real estate and finance allows her to uniquely understand her clients' needs and concerns in today's fast-paced market. As a former financial services executive with extensive team-building and negotiation experience, Karen has the proven ability to meet and exceed her client's goals. Karen utilizes a project management discipline to ensure all steps in the real estate transaction process move smoothly and stress free. Karen's extensive professional and personal network, which includes bankers, contractors, and design professionals, allows her to assemble the perfect team for each of her clients.

Karen enjoys building relationships through increased understanding, honesty and trust to foster inclusion in all aspects of the buying and selling process. She is an empathetic listener, responsive to her clients' inquiries and drives forward to achieve amicable solutions to real estate dilemmas.

Prior to residential real estate sales, Karen held a successful tenured position on Wall Street where she both analyzed residential mortgage debt offerings and managed client relationships.

Karen was raised on the North Fork of Long Island and has resided and worked in Manhattan since graduating college. Karen is currently living in the Chelsea neighborhood of Manhattan with her husband who is also in the real estate profession as a private lender and developer in the tri-state area. Karen currently volunteers at the NYU Career Services Center, is a New York Cares Kaplan SAT tutor, and a SIFMA Invest Write Essay Judge. She enjoys the arts, cooking, running, playing tennis in Central Park and exploring the neighborhoods and restaurants within the five boroughs.

Karen is a dual licensed salesperson in New York with Warburg and in New Jersey with Elite Realtors. She is a member of the Real Estate Board of New York (REBNY) with a board-certified designation of New York Residential Specialist (NYRS®), as well as a member of the National Association of Realtors and the Multiple Listing Service of Garden State, New Jersey and Hudson County. She is also a member of the Financial Executive Networking Group (FENG), Risk Management Association (RMA) and Society of Human Resource Managers (NY SHRM).

Visit my website: KarenKostiw.com


By now, you’re probably aware the housing market’s changing. But is it a “buyer’s market” just yet? That depends on who you ask — and, more importantly, where they’re located. At its core, real estate is a… More
Apartment Therapy
It’s a buyer’s worst nightmare: Walking into a home and seeing the dreaded texture of a popcorn ceiling staring down at them from above. The same goes for real estate agents. I spoke to seven of them for… More
Apartment Therapy
Home sales get put on hold for any number of reasons. Maybe there’s been a medical emergency and the seller can’t continue showing at that point in time. Or maybe the seller no longer has a place… More
Brick Underground
Finding a rental apartment in New York City is notoriously hard—and finding a short-term, furnished rental here is even harder. I’s a dilemma you may face if you’re relocating here for work or if you are renovating…. More
After getting the keys to their new place, buyers might be surprised to stumble across items that the sellers left behind. “Moving is a very stressful time for both purchasers and sellers,” says Karen Kostiw, an agent… More
Apartment Therapy
The past two years have seen countless clever closet hacks. From offices (and more offices… and more offices) to nurseries to music studios to mudrooms, the multi-use closet is having a moment. If you’re lucky enough to have an abundance of closet space, these brilliant… More
Apartment Therapy
My partner and I are house shopping right now. Though we expected high prices and homes selling quickly, there’s one thing we didn’t expect: wood paneling. And I mean lots of wood paneling. It seems like nearly every… More
Apartment Therapy
According to Kristina Morales, strategic real estate advisor at MultifamilyCashin, architectural elements of homes largely escaped 1980s design trends — but the same can’t be said for interior design, where the vibrant culture of the era took hold. https://www.apartmenttherapy.com/real-estate-trends-80s-37059784
Brick Underground
It sounds like you have lucked out if there’s a vacant apartment in your building that’s available to you. Apartment hunters are facing lots of competition in the New York City rental market today, including much… More
Brick Underground
If you’re looking to buy an apartment in Manhattan you’re likely experiencing some sticker shock. Covid deals are long gone and prices have rebounded to 2019 levels. But there is one type of apartment where prices have not… More
21 Oak
Taking on a home remodeling project is always exciting, but not every home “improvement” is actually an improvement. Many renovations don’t translate to increased home value and instead wind up costing more time and money. And… More
One of the wonderful things about living in NYC is every neighborhood has some sort of dining scene and a variety of attractions. But Soho is one of those areas that’s packed full of them. Not… More
StreetEasy Blog
Karen Kostiw and Sheila Trichter comment. What To Know About (Fabulous) Midtown, Manhattan
Brick Underground
Karen Kostiw comments. https://www.brickunderground.com/improve/how-much-does-it-cost-to-paint-my-nyc-apartment
Multifamily Magazine
Karen Kostiw comments. https://www.multifamilyexecutive.com/property-management/apartment-trends/the-pandemic-has-changed-everythingincluding-on-site-fitness-facilities_o
AsAm News
Karen Kostiw comments. https://asamnews.com/2021/12/30/this-as-the-asian-population-elsewhere-in-ny-increases-some-blame-gentrification/
StreetEasy Blog
Sheila Trichter and Karen Kostiw comment https://streeteasy.com/blog/midtown-manhattan-great-place-to-live/
Brick Underground
Jeremy Kamm and Karen Kostiw comment https://www.brickunderground.com/rent/when-to-use-broker-agent-find-rental-apartment-listings-nyc
StreetEasy Blog
Karen Kostiw comments https://streeteasy.com/blog/nyc-building-complaints-how-to-check-alandlord/
Apartment Therapy
Karen Kostiw and Becki Danchik comment. https://www.apartmenttherapy.com/inclusive-real-estate-listing-language-37002463
Brick Underground
Karen Kostiw comments. https://www.brickunderground.com/improve/renovation-solutions-supply-chain-issues-shortages-delays-NYC-apartment-brownstone-appliances-lighting-furniture-fixtures
Business Insider
Karen Kostiw and Rebecca Blacker comment. https://www.businessinsider.com/how-to-write-the-best-offer-letter-for-a-house
Business Insider
Karen Kostiw, Rebecca Blacker, and Gerard Splendore comment. https://www.businessinsider.com/the-most-common-homebuying-mistakes-and-how-to-avoid-them
Brick Underground
Karen Kostiw & Adjina Dekidjiev comment. https://www.brickunderground.com/rent/realty-bites-getting-rid-of-stuff-left-by-previous-tenant-renters-landlords-nyc
Brick Underground
Sarah Minton, Ellen Sykes, Karen Kostiw and Gerard Splendore comment. https://www.brickunderground.com/rent/tips-rental-nyc-competitive-market-fast-brooklyn-queens-broker-building-apartment
The New York Times
Karen Kostiw comments. https://www.nytimes.com/interactive/2021/08/26/realestate/26hunt-hart.html
Karen Kostiw and Jeanne Byers comments. https://streeteasy.com/blog/kensington-brooklyn-affordable-for-renters-buyers/
Karen Kostiw and Elizabeth O’Neill comment. https://streeteasy.com/blog/what-is-a-land-lease-building-in-nyc/  
Karen Kostiw and Svetlana Choi comment. https://streeteasy.com/blog/what-is-an-hdfc-co-op/  
Karen Kostiw & Annie Gruenberger comment. https://www.marthastewart.com/8120525/post-moving-new-home-checklist
Crain's New York
Karen Kostiw & Maria Daou comment. https://www.crainsnewyork.com/residential-real-estate/west-coast-techies-relocate-manhattan-home-sales-heat
Grow by Acorns + CNBC
Karen Kostiw comments. https://grow.acorns.com/how-higher-home-prices-affect-what-you-need-for-a-down-payment/
Real Simple Magazine
Gerard Splendore, Karen Kostiw and Svetlana Choi comment. https://www.realsimple.com/home-organizing/home-improvement/top-home-features-2021
Karen Kostiw & Gerard Splendore comment. https://www.forbes.com/sites/amandalauren/2021/06/14/ten-best-outdoor-design-trends-of-2021/?sh=e15321d2b7a2
Karen Kostiw comments. https://www.bobvila.com/articles/things-every-buyer-needs-to-know-when-its-a-sellers-market/
FOX Business
Christopher Totaro and Karen Kostiw comment. https://www.foxbusiness.com/money/buying-new-construction-home
The Close
Karen Kostiw and Andrea Warshaw-Wernick comment. https://theclose.com/real-estate-apps/
Bank Rate
Emily Becker & Karen Kostiw comment. https://www.bankrate.com/mortgages/pandemic-appliance-shortage/
Karen Kostiw comments. https://www.marthastewart.com/8094493/buying-a-second-home-tips
Brick Underground
Karen Kostiw and Sheila Trichter comment. https://www.brickunderground.com/rent/realty-bites-landlord-offering-discount-scaffolding-construction-noise-leases-tenants-nyc
Bob Vila
Mihal Gartenberg, Karen Kostiw, and Christopher Totaro comments. https://www.bobvila.com/articles/did-you-know-you-could-negotiate-this-when-buying-a-house/
Real Homes
Mihal Gartenberg, Bill Kowalczuk, Karen A. Kostiw, and Parisa M. Afkhami comments. https://www.realhomes.com/us/news/the-one-reason-you-should-always-walk-away-from-a-home-sale-according-to-realtors
Apartment Therapy
Ellen Sykes and Karen Kostiw comments. https://www.apartmenttherapy.com/trendy-studio-apartment-layouts-36881968?
Real Homes
Karen A. Kostiw, George Case and Kathryn Landow comment. https://www.realhomes.com/us/news/best-color-to-paint-your-house-before-you-sell
Steven Gottlieb, Parisa Afkhami, Steven Goldschmidt, Karen Kostiw, and Gerard Splendore comment. https://streeteasy.com/blog/buying-a-home-in-nyc-everything-you-need-to-know/  
Karen Kostiw comments. https://www.realtor.com/advice/buy/failed-initial-real-estate-inspection-how-to-get-through-escrow/
Brick Underground
Mihal Gartenberg and Karen A. Kostiw comments. https://www.brickunderground.com/rent/realty-bites-renting-nyc-apartment-on-unemployment-do-i-need-guarantor
Apartment Therapy
Karen Kostiw comments. https://www.apartmenttherapy.com/real-estate-agents-hate-white-kitchen-cabinets-36850921?
George Case and Karen Kostiw comment. https://www.marthastewart.com/8023158/paint-colors-increase-home-value
Karen Kostiw’s client at 100 Barclay mentioned, June Gottlieb comments. https://www.forbes.com/sites/ellenparis/2020/10/31/manhattans-rental-market-is-all-about-concessions-and-more-concessions/?sh=28bf826860ca
Karen Kostiw comments. https://money.com/coronavirus-skip-home-inspection/
Christopher Totaro and Karen Kostiw comment. https://www.rentcafe.com/blog/apartment-search-2/rental-scams/
The New York Times
Karen Kostiw and her client featured in “The Hunt” https://www.nytimes.com/interactive/2020/09/24/realestate/24hunt-woodhouse.html?mtrref=undefined&assetType=REGIWALL  
Karen Kostiw comments. https://www.inman.com/2020/09/04/looking-for-a-better-deal-consider-the-condo/
The New York Times
Karen Kostiw and her client featured in “The Hunt” https://www.nytimes.com/interactive/2020/07/16/realestate/16hunt-hagstrom.html
Gill Chowdhury, Karen Kostiw, and Jeanne Byers comment. https://www.hunker.com/13727043/confusing-real-estate-terms-explained
Apartment Therapy
Karen Kostiw comments. https://www.apartmenttherapy.com/apartment-dishwashers-36712385
Brick Underground
Karen Kostiw comments. https://www.brickunderground.com/buy/buy-curious-what-new-yorkers-need-to-know-about-moving-to-weehawken
Apartment Therapy
Wendy Arriz and Karen Kostiw comment. https://www.apartmenttherapy.com/real-estate-agent-hiring-36646585
Karen Kostiw, Nicole Durosko, and Steven Gottlieb comment. Porthole Windows: They’re Not Just for Ships and Boats
Karen Kostiw comments. https://www.realtor.com/advice/buy/what-does-move-in-ready-mean/
Karen Kostiw and Nicole Durosko comment. Incorporating Dome Ceilings in Your Home’s Design
Real Estate Weekly
234 W21st St. #55 by Gannon Forrester and 225 E36th St. 8H by Karen Kostiw mentioned. DONE DEALS: Big deal on little house in Park Slope
Apartment Therapy
Broker Karen Kostiw comments. https://www.apartmenttherapy.com/landscaping-mistakes-36616688
Apartment Therapy
Karen Kostiw comments. https://www.apartmenttherapy.com/fixer-upper-real-estate-legacy-35819141
Karen Kostiw pens a column. https://www.inman.com/2019/05/10/how-to-explain-home-inspections-to-buyers/?utm_source=dailyheadlines&utm_medium=email&utm_campaign=localnewsletter&utm_content=733287_textlink_7_
Karen Kostiw comments. https://www.realtor.com/advice/buy/pros-and-cons-of-writing-a-personal-offer-letter/
Karen Kostiw comments. https://freshome.com/buying-fixer-upper-considerations/
Agents Gill Chowdhury, Karen Kostiw, and Wendy Arriz comment. https://www.brickunderground.com/buy/what-is-a-nyc-pied-a-terre-bricktionary?utm_source=Brick+Underground+Newsletter&utm_campaign=4022ac7ff4-EMAIL_CAMPAIGN_2019_03_07_08_00&utm_medium=email&utm_term=0_2fdec7634c-4022ac7ff4-85748141
Apartment Therapy
Julia Leigh Surgeon, contact of Allison Chiaramonte comments; Jennifer Weisberg, contact of Eric Mendelsohn comments; Kelly Rosen Lagrange, contact of Karen Kostiw comments. https://www.apartmenttherapy.com/open-concept-layout-mistakes-266464
Apartment Therapy
Karen Kostiw talks about how to learn about your landlord before moving in. https://www.apartmenttherapy.com/questions-to-ask-landlord-before-moving-in-264592
House Method
Alex Lavrenov and Karen Kostiw talk about things to know when paying off your mortgage early. https://housemethod.com/real-estate/paying-off-mortgage-early/
New York Times
Karen Kostiw featured. https://www.nytimes.com/2018/11/08/realestate/the-beauty-of-a-no-nothing-walk-up.html
The New York Times
Karen Kostiw helps a young, newly married couple find their perfect apartment in Yorkville. https://www.nytimes.com/2018/11/08/realestate/the-beauty-of-a-no-nothing-walk-up.html
Karen Kostiw writes a column about how to stay connected with your clients. https://www.inman.com/2018/10/10/share-a-fall-home-maintenance-checklist-for-homeowners/
Apartment Therapy
Karen Kostiw talks about plants and which landscapes make a home feel like a home. https://www.apartmenttherapy.com/front-yard-plant-tips-landscapers-263338
The Real Deal
Karen Kostiw is featured. https://www.karenkostiw.com/wp-content/uploads/2018/10/10.1.2018-TRD-Charlton-Avenue-.pdf
Wall Street Journal
The photo of Karen Kostiw’s listing in Oradell, NJ and its “For Sale” sign outside was used in a story about national home continuing to increase. http://www.wsj.com/articles/home-prices-continued-to-climb-in-march-1432645221
Mann Report Newswire
Warburg Realty®, one of Manhattan’s leading residential real estate companies, is looking to open its first Brooklyn office in 2014, announced Frederick Warburg Peters, president of Warburg Realty. The firm has also begun the redesign of… More
Press Release
Warburg Realty, one of Manhattan’s leading residential real estate companies, is looking to open its first Brooklyn office in 2014, announced Frederick Warburg Peters, president of Warburg Realty.  The firm has also begun the redesign of… More


Testimonial from Belinda and Gary

Karen and I were co-workers in the finance industry prior to her becoming a realtor.  Choosing her as my realtor for a purchase of a condo in NYC was not a difficult decision, as I knew the quality of her work, albeit in another industry.


I was spot on! I went into the search thinking I knew exactly what I was looking for.  Karen showed me numerous condos that fit my parameters but none of them “hit the spot”.  However, from my comments, she was quietly taking notes on what I really wanted.  One day she just took me to see a condo that wasn’t on my list, saying: I think you will like it.  It hit the spot immediately and it is the one I purchased.


She is also extremely knowledgeable about the market and real estate negotiation.  She is always timely, accurate in her responses, courteous and professional.


I would highly recommend her to anybody purchasing a home in NYC.

Testimonial from Judith

Karen was the ideal realtor for our needs.  We found our beautiful apartment with incredible architectural features in Midtown East after 2.5 days of visits to numerous locations, all happening smoothly and efficiently due to Karen’s expertise.  Karen listened to every detail of what we wanted, open minded and interested in us.  As out of towners, we learned a lot, with Karen providing information and context on everything.  Our instincts to be in a central location really paid off, and we could not be happier.  Although the application and board interview took some time, we had patience with the process, due to Karen’s coaching.  I cannot imagine a real estate agent who could have been more attentive and professional.  As challenging as it is to buy in Manhattan, Karen made every step seem possible as we went through the purchase process.

Testimonial from Krishna Murali

I am delighted to be writing this testimonial on behalf of Karen Kostiw. Karen is the perfect real estate agent because of her deep real estate domain expertise, her relentless work ethic and her genuine compassion and care for her clients. As a first time home buyer, it was invaluable to have Karen to help me navigate the New York real estate market. Karen was able to guide me through every step of the process, always having answers and perspectives, no matter how niche my questions were. More impressively, Karen worked around the clock to help ensure a smooth transaction. There were many moments during the process where things went wrong, or parties were slow in responding – Karen navigated through all of these hurdles with ease, many times having late night conversations with different parties to smooth over all issues. Having Karen on your side is a real asset, especially during competitive processes. Finally, it was apparent right from the get-go that Karen genuinely cares for her clients. It was really touching how invested she was in the process, and how happy it made her to help me find my dream home. Even after the process, Karen was consistently in touch, offering to help, providing invaluable design advice, and just generally being amazing. Thank you Karen for all that you did for me! I could not be happier writing this testimonial on your behalf!

Testimonial from Brian

As a first time home/apartment buyer, I was nervous and insecure about jumping into the process. Karen calmed my worries, and guided me through the entire process with ease. I was able to trust her implicitly, as she was my greatest advocate – fighting for me to get to see apartments I liked, being a strong negotiator once I put down an offer, and putting together a board package that sailed through the approval process extremely quickly. She always listened to and respected my wants, and was consistently available to take my questions and to help me talk through items I wished to sort out. Additionally, she was very helpful in talking through decoration ideas, and introducing me to all the necessary contacts I needed throughout the process. She was also very helpful in getting me acclimated to the climate of the market during the pandemic, and taught me how to evaluate the landscape of the industry in New York City. Karen came as a recommendation from a friend, and I’ve already recommended her to a few friends as well. I’m hopeful we’ll work together again one day.

Testimonial from Stella

Karen was way beyond a professional agent who helped me not only with going through all the progress of purchasing a house, but was also a friend to me. She could always arrange all the appointments perfectly to match my limited schedule and listened to my preferences and concerns and made recommendations based on that. She was also so experienced in negotiation, which is probably the most important step in purchasing or selling. She is definitely an awesome agent that you will be really happy to work with.

Testimonial from Russ

Karen was a very professional, diligent, and overall reliable agent when working through the process of buying my home. As it was a first home for me, there was definitely some hand-holding along the way (which was necessary). I gave her the specs as well as the area(s) I wanted to purchase my home, and she was readily available with recommendations/opinions. Not only was she able to provide apartment advice, she had a long list of preferred attorneys/architects/contractors/banks etc. for the closing process. Without her expertise, the process would have been quite a bit more stressful. I highly recommend her for any purchases within Manhattan as it was a very seamless process.

Testimonial from Eric

Karen was a great agent for a first time homebuyer in NYC. She helped me go through the process (including coop board approval) extremely quickly, I was in my lovely new apartment in no time. She is very helpful and willing to take a lot of work off my shoulders. She also helped negotiate the purchase price lower which I greatly appreciated.

Testimonial from Kim

Karen is the best! Being new to the buying process, Karen graciously walked me through each step from the beginning to the closing. I wanted to see as many co-ops as I could to get a better understanding of what I wanted with what was available on the market. Karen’s knowledge and experience in Manhattan realty really helped me filter my list. She also made viewing appointments fast and organized them in the most efficient way so I could maximize my time. She gave me great advice throughout the process and was available 24/7 with answers to any questions I had. She was always very informative, endlessly helpful and a joy to work with throughout this process. She has great recommendations for everything from lawyers to contractors and has great intel about interior design. If you want a broker who goes above and beyond to help you purchase the perfect apartment, I would highly recommend Karen.

Testimonial from Joan & Ed

Selling an apartment in the highly competitive NYC market is a challenge. Karen understood our requirements and became our 24/7 person. She guided us through the process of obtaining painting, and floor contractors as well as plumbers, window washers, etc. Karen was with us from the initial showing through the recent closing. If we were to purchase again in the city, Karen is our go-to-person. Highly recommend her.

Testimonial from Carl and Amy

Karen was very responsive and helpful throughout the home purchase process for my wife and I. She was readily available to chat when needed, took care of answering our questions (or pointing us in the right direction to another resource where applicable), and helped to keep our best interests in mind from beginning to end.

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