In New York City, some of the most undervalued townhouses on the market are former SRO properties. While these buildings offer significant upside, converting them back to single-family homes is legally and technically complex. After the Great Depression, many townhouses in New York City were subdivided into Single Room Occupancy (SRO) buildings to provide affordable housing. These grand single-family brownstones were reconfigured into multiple small units, often with shared bathrooms and kitchens serving each floor. Today, some buyers are purchasing these SRO townhouses and restoring them to their original configuration as single-family homes. While this can be an effective way to reposition an undervalued property, the process is technically complex.
Converting an SRO townhouse back to a single-family home in NYC requires regulatory approvals, including obtaining a Certificate of No Harassment from the New York City Housing Preservation and Development (HPD) before permits can be issued by the New York City Department of Buildings (DOB). Upon completion of the work and successful inspections, a new Certificate of Occupancy reflecting single-family use must be issued.
I am Jorge Fontan AIA, an architect in New York and owner of Fontan Architecture. Our firm works on a range of residential projects in NYC, including townhouse renovations and converting SROs back to single-family townhouses. In this article, I will outline the general process, regulatory requirements, and key considerations involved in converting an SRO townhouse back to a single-family home.
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What is an SRO?
SRO stands for Single Room Occupancy. In New York City, the term generally refers to buildings that contain individual rental rooms with shared bathroom and, in some cases, kitchen facilities.
SRO units in townhouses typically operate as Class B multiple dwellings, commonly referred to as “rooming houses”. In this arrangement, occupants rent a single private room, while bathrooms and sometimes kitchens are shared on each floor.
Many of these buildings were originally constructed as single-family townhouses and were later subdivided into multiple rooms. Converting an SRO townhouse back to single-family use typically involves reversing these alterations and complying with current zoning and building code requirements while making all necessary renovations needed to the home.
Verify the Legal Status of an SRO
Before planning any conversion, the first step is to confirm the building’s current legal occupancy classification. Assumptions are risky. The legal use of the property must be verified through official records.
As an architect, the key documents we review include the Certificate of Occupancy issued by the New York City Department of Buildings (DOB), as well as historical occupancy records such as the I-Card maintained by the New York City Housing Preservation and Development (HPD).
These records establish whether the property is legally registered as a Class B rooming house, whether it was altered over time, and whether there are discrepancies between current conditions and approved use. They are foundational to determining what approvals will be required for a change back to single-family occupancy.
As architects experienced in townhouse alterations, we review these records, identify inconsistencies, and assess the feasibility of conversion before design work begins. For buyers considering the purchase of an SRO property, this type of review should be conducted before closing, as part of a broader architectural due diligence process.
Obtain a Certificate of No Harassment (CONH)
To convert an SRO townhouse to single-family use in New York City, a Certificate of No Harassment (CONH) is required. This certificate is issued by the New York City Housing Preservation and Development (HPD) and must be obtained before the New York City Department of Buildings (DOB) will approve permit applications for properties designated as SRO-restricted.
The CONH process can be time-consuming, often taking nine to twelve months. HPD reviews the building’s occupancy history to determine whether tenant harassment occurred during a specified inquiry period. Without an approved CONH, DOB will not issue permits for alteration work associated with the change of use.
Vacancy is typically required for conversion. In many cases, a property may be delivered vacant at closing, but buyers should consult an attorney to ensure that prior tenant removals were conducted legally and in compliance with applicable housing laws. Legal counsel is generally retained to manage the CONH application process and coordinate with HPD.
Engage an Architect
An SRO conversion is not a cosmetic renovation. It involves a change of legal occupancy, significant interior reconfiguration, and compliance with current building and fire safety codes. As such, it requires the services of a licensed architect.
The architectural process typically begins with a comprehensive assessment of the existing building, including structural conditions, egress configuration, mechanical systems, building records review, and regulatory constraints. This evaluation informs the feasibility of conversion and the scope of required work.
Once feasibility is established, the architect develops a design that reconfigures the townhouse back to single-family use while aligning with the owner’s programmatic and aesthetic needs. SRO conversions often involve full interior reconstruction, replacement of building systems, and coordination with structural and mechanical engineers.
Following design development, the architect and consulting engineers prepare construction documents for filing with the New York City Department of Buildings. Upon approval, the project proceeds to construction.
During construction, we provide construction administration services, including site visits, coordination with the contractor, and review of work for conformance with the design intent. At completion, the architect assists with project closeout and the issuance of a new Certificate of Occupancy reflecting single-family use.
File an Alteration-CO (Alt-1)
Converting an SRO townhouse back to single-family use requires filing an Alteration-CO (ALT-CO) Application (formerly Alt-1 / Alteration Type 1) application with the New York City Department of Buildings. An Alt-CO filing is required whenever work results in a change of use, egress, or occupancy that necessitates the issuance of a new Certificate of Occupancy.
Because an SRO conversion involves a change from Class B rooming house use to Class A single-family occupancy, an Alt-CO filing is required. This is not a minor alteration; it is a formal change in the building’s legal status.
The DOB will review the application, including architectural and engineering plans, code compliance, and zoning considerations. The application will not be approved without a valid Certificate of No Harassment (CONH), where required. Upon completion of the work and final inspections, DOB will issue a new Certificate of Occupancy reflecting single-family use.
Renovating
Once the alteration application is approved, the contractor may obtain permits and begin construction. At this stage, the project transitions from regulatory approval to physical transformation of the home.
SRO conversions typically involve extensive interior reconstruction. In many cases, for a townhouse renovation in NYC non-compliant partitions are removed, floor layouts are reconfigured, and building systems are fully replaced. Plumbing risers, electrical infrastructure, heating systems, and fire safety components often require complete modernization to meet current code requirements.
Throughout construction, the architect coordinates with the contractor and consultants, responds to field conditions, and assists in resolving unforeseen issues. DOB inspections are conducted at various stages of the work, and compliance must be verified before final sign-off.
While some SRO properties may be in relatively stable condition, many require significant upgrades to meet current structural, fire safety, energy, and accessibility standards. The architectural and engineering team evaluates these conditions and directs the necessary corrective work to achieve legal single-family occupancy.
New Kitchen in a Manhattan Townhouse – Renovating a Brownstone in NYC
Obtain a New Certificate of Occupancy
After construction is completed and all required inspections have been passed, the architect submits final documentation to the New York City Department of Buildings (DOB) for sign-off. Upon approval, DOB issues a new Certificate of Occupancy reflecting the updated legal use of the building.
At that point, the property is no longer classified as a Class B SRO. It is legally recognized as a Class A single-family dwelling under New York City regulations.
The issuance of the new Certificate of Occupancy is the final regulatory step in converting an SRO townhouse back to single-family use.
Brownstone Open Parlor Floor
SRO Conversion to a One-Family Home in NYC
Converting an SRO townhouse back to single-family use is achievable, but it requires careful coordination of legal occupancy, regulatory approvals, and substantial renovation work.
Because SRO conversions involve changes in legal occupancy, building code compliance, and substantial interior reconstruction, feasibility should be evaluated carefully before a property is purchased or renovation work begins. In practice, most SRO conversions function as comprehensive townhouse renovations rather than limited alterations.
If you are considering converting an SRO townhouse in New York City, Fontan Architecture provides architectural feasibility studies, regulatory analysis, and full design services for townhouse renovations. Early consultation can help clarify scope, timeline, regulatory requirements, and feasibility — particularly when evaluating a property prior to purchase.
Request a Consultation with Fontan Architecture
This post was written by Jorge Fontan AIA a Registered Architect and owner of New York City architecture firm Fontan Architecture. Jorge Fontan has earned 3 degrees in the study of architecture including two degrees from the City University of New York and a Masters Degree in Advanced Architectural Design from Columbia University. Jorge has a background in construction and has been practicing architecture for 20 years where he has designed renovations and new developments of various building types.
