Due Diligence Checklist: Manhattan & Brooklyn Condos

Over the 90 days to October 1, 2026, the median Manhattan condo closed at $1,604 per square foot and the median Brooklyn condo at $1,379, per the RLS feed. On a 900-square-foot apartment, that is a difference of about $200,000 before a single inspection or financial review. In my 25+ years selling NYC real estate, I have seen buyers lose real money by skipping steps that take a few hours of review. This checklist covers the condo-specific due diligence in Manhattan and Brooklyn, from the offering plan to the building's financials.

Manhattan vs. Brooklyn Condos: The Numbers

Compare any apartment you are considering with these medians and with recent sales in its own building, which is where comparable-sales analysis matters most.

1. Building Financials and Governance

This is where condo buyers get hurt, and where a home inspector cannot help you. Ask your attorney to obtain and review:

Ask the managing agent about unpaid common charges, pending litigation and planned capital projects. Review the monthly carrying cost in full: mortgage, real estate taxes, common charges and utilities. See our closing costs breakdown for the upfront expenses and the pre-approval guide to start the financing conversation.

2. Building Condition and Compliance

• Hire a licensed inspector who knows NYC buildings to check the unit's structure, electrical, plumbing and HVAC, and look for water stains, cracks and signs of pests.
• Ask about facade work. Buildings taller than six stories must be inspected on a recurring cycle under the city's facade inspection program, and repairs can drive assessments.
• Ask about Local Law 97. Buildings over 25,000 square feet face emissions limits, and meeting them can require capital spending.
• Check violations for the building with the NYC Department of Buildings and HPD before you offer.

Active Condo Listings in NYC

Use our due diligence checklist when evaluating these properties

View All

Active

$799,000

593 E 17TH Street #3C

Ditmas Park

2 bd 2 ba 760 sf

View Details Tour

Condo · 2026 RLS #RLS20113113

Active

$1,999,000

408 E 79th Street #3A

Upper East Side

2 bd 2 ba 1,465 sf

View Details Tour

Condo · 2005 RLS #RLS20100317

Listing information provided courtesy of the Real Estate Board of New York's Residential Listing Service (RLS). Information is deemed reliable but not guaranteed. Sale listings verified. ©2026 REBNY. RLS data displayed by Keller Williams NYC.

3. Title, Ownership and Records

A title search confirms the seller can transfer clear ownership and shows liens or other claims against the unit. Hire a title company or real estate attorney, and run a preliminary check yourself on ACRIS, NYC's free property records system, to spot liens or ownership gaps early.

4. Legal Checks

• Condo vs. co-op: Understand the structure you are buying. Co-ops usually have stricter board approval processes, while condos typically offer more flexibility. See the co-op vs. condo guide, and if the building is a co-op, the co-op board interview guide.
• Contract: Have your attorney review contingencies, timelines and obligations before you sign.
• Disclosure: Under New York's Property Condition Disclosure Act, a seller must either provide the disclosure statement or credit the buyer $500 at closing. See the NYC seller disclosure requirements guide.

Your Roadmap to a Successful Purchase

Buying a condo in Manhattan or Brooklyn calls for a meticulous approach: confirm the price against comparable sales, review the building's financials and governing documents, inspect the unit, clear the title, and have an attorney review the contract. To talk through a specific building, call me at (917) 416-7433.

About the Author

Milton Coste is a Licensed Real Estate Associate Broker with Keller Williams NYC, with more than 25 years of experience and 1,100+ NYC property transactions marketed, leased and sold. Bilingual in English and Spanish, he gives buyers direct, experienced guidance on the NYC market.

Active Listings

Milton Coste

Licensed Real Estate Associate Broker · Keller Williams NYC

License No. 10301213304 · 360 Madison Avenue, 9th Floor, NY 10017

(917) 416-7433 milton@miltoncoste.com miltoncoste.com

Equal Housing Opportunity. We are pledged to the letter and spirit of U.S. policy for the achievement of equal housing opportunity throughout the Nation. Milton Coste and Keller Williams NYC are committed to full compliance with the Federal Fair Housing Act (42 U.S.C. §§ 3601-3619), the New York State Human Rights Law (Executive Law, Article 15), and the New York City Human Rights Law (Title 8, NYC Administrative Code).

MLS & Listing Data Disclaimer: This information is not verified for authenticity or accuracy and is not guaranteed and may not reflect all real estate activity in the market. ©2026 The Real Estate Board of New York, Inc. All rights reserved. Listing information is provided solely for consumers' personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Listing data sourced from REBNY RLS and OneKey MLS. Listing Courtesy of Keller Williams NYC.

Financial & Market Data Disclaimer: All financial figures, market statistics, price estimates, and rental rates are sourced from StreetEasy Market Reports and provided for informational purposes only. Market conditions change frequently. This content does not constitute financial, tax, investment, or legal advice. Consult a licensed financial advisor, CPA, or attorney before making financial decisions. Published in accordance with 19 NYCRR Part 175 (NY DOS Real Estate Broker Advertising Regulations). Milton Coste operates as a Licensed Real Estate Associate Broker under the supervision of Keller Williams NYC.

Content published: February 2026 · Milton Coste · Keller Williams NYC · License No. 10301213304