Purchasing a NYC co-op with the intent of renovating it prior to moving in is one of the most common renovations we take on at Gallery. Given the age and condition of most NYC co-op’s plus the demanding boards, city rules, and management companies is what gives many buyers angst and creates obstacles that could cause your dream home design to be adjusted.
About Gallery KBNY
Gallery KBNY is an award-winning, full-service design-build firm specializing in the architecture, interior design, and renovation of apartments, co-ops, condominiums, townhomes, and lofts across Manhattan and Brooklyn. Our integrated team of architects, designers, contractors, and project managers — with a founding partner involved in every project — manages every phase from board approvals and DOB permitting through design and construction. Because architecture, design, permitting, and construction are coordinated under one roof, the process remains streamlined, accountable, and transparent from start to finish. Our work has been recognized by Forbes, The New York Times, Architectural Digest, and Inc., and we have received Houzz Best of Design & Service seven consecutive years, along with 100+ five-star client reviews.
At Gallery, we excel at co-op and condo renovations in New York City, and have outlined various considerations below to provide proper expectations for anyone about to navigate a co-op renovation in NYC.
[#Navigating]Navigating the Co-Op Board Approval Process[#Navigating]
Co-op renovations in NYC have plenty of red tape and come with added bureaucratic details to account for before any alterations can begin.
Alteration Agreement
Once you decide upon a co-op renovation, the first step is to request an alteration agreement from the building management company. In short, an alteration agreement provides rules and governs renovations in the co-op building. It is set up by the co-op board and management company to ensure everything needed for the renovation is up to code, including insurance requirements and various technical elements.
What's Inside An Alteration Agreement?
Alteration agreements typically contain all of the following information:
Times of work and noise hours
Duration of a renovation (sometimes buildings only allow for 90 days or 120 days, after which a penalty is incurred)
Requirements for plumbing and electrical work
All insurance document requirements
Specs of all plumbing and electrical fixtures to be used
Requirements for asbestos and lead testing along with abatement requirements
Description of factors that trigger architectural plans
Requirements from your contractor
Virtually every co-op in New York will require compliance with the alteration agreement prior to allowing your renovation project to commence. The process of satisfying the alteration agreement on larger projects such as complete gut renovations, apartment combinations, or multi room remodels can be lengthy and time consuming, highlighting the importance of having an expert navigate the process.
Dedicating the time and effort to make sure everything in your alteration agreement is picture perfect prior to submission is essential to a seamless approval process. At Gallery, handling alteration agreement submissions is one of our specialties, which will ensure your project approval process runs as smoothly as possible. Board rapport is important because co-op boards and their reviewing architects will often provide a laundry list of adjustments required before work can begin - which we always help our clients work out appropriately.
When planning the architectural design for your upcoming co-op renovation, the following caveats should be kept close in order to properly anticipate any specifications that may restrict specific layout changes:
Wet-Over-Dry Restrictions
Wet-over-dry restrictions dictate whether or not you can physically relocate what is deemed a ‘wet’ area (typically, a bathroom and kitchen) over a ‘dry’ area (the bedroom or living room of your neighbor directly below. Typically, this is not allowed in most NYC buildings.
Plumbing Risers
Plumbing stacks dictate whether or not you can open up certain walls in kitchens and bathrooms. Pipe systems in most NYC buildings run vertically and horizontal movement is often frowned upon by co-op boards, due to the potential for disruption to other tenants.
Alteration Permits
When making layout changes during your condo or co-op renovation, you will need the proper work permit from the NYC Dept. Of Buildings. There are two types of permits:
Alteration Type 1: Required if there will be structural changes made to the building - which would be rare in most common co-op renovations and applies to more significant speciality jobs like an apartment combination.
Alteration Type 2: Required during any renovation that requires work behind the walls, including replacing old electrical wiring, re-routing lines, plumbing updates, etc. A type 2 permit is needed in the majority of our condo and co-op renovations in NYC.
Layout Restrictions
What Co-Op Boards Typically Allow, Restrict, And Deny
Proposed Layout Change
Typical Feasibility
Permit Required
Why It Matters
Cosmetic Refresh
Generally Allowed
No DOB Permit
Paint, flooring, fixtures, and cabinetry replacement that do not touch electrical, plumbing, or structural systems clear most alteration agreements without architectural plans.
Electrical Or Plumbing Upgrade In Place
Generally Allowed
Alt-2 Permit
Replacing wiring or fixtures within existing locations requires permit filing, board insurance compliance, and a licensed contractor on the approved list.
Non-Load-Bearing Wall Removal
Generally Allowed
Alt-2 Permit
Opening a non-structural interior wall to combine rooms or improve flow is routinely approved with architectural plans submitted to the board and DOB.
Bathroom Or Kitchen Layout Shift Within Wet Zone
Conditional
Alt-2 Permit
Moving fixtures within an existing wet area is often allowed, but plumbing riser locations and waste line routing must be respected. Plans typically require board engineer review.
Adding A New Bathroom Or Kitchen Over Dry Space
Usually Restricted
Alt-2 + Board Waiver
Wet-over-dry restrictions typically forbid placing a new wet area above a neighbor's living or sleeping space. Board waiver is possible but rare and requires extensive sound and waterproofing scope.
Horizontal Plumbing Reroute Across Risers
Usually Restricted
Alt-2 + Board Approval
Most NYC co-op risers run vertically. Horizontal movement across stacks introduces neighbor disruption risk and is often denied unless tied to an approved building-wide plumbing strategy.
Load-Bearing Wall Removal Or Apartment Combination
Conditional
Alt-1 Permit
Structural changes require an Alt-1 filing with sealed engineering drawings, full DOB review, and explicit board approval. Common on combinations and gut renovations but adds weeks to permitting.
Window Replacement Or Facade Penetration
Building-Specific
Varies
Facade work touches a co-op's common elements. Approvals depend on the building's standard window spec, landmark status, and whether replacements are tied to a building-wide program.
Source: Gallery KBNY co-op alteration agreement framework, Manhattan and Brooklyn (2026). Specific rules vary by building; this matrix reflects patterns common across NYC co-op alteration agreements.
In certain circumstances, if proposed layout changes from our clients are being disallowed by the co-op board then we’ll petition the co-op board to make an exception. We will only do this in certain cases, if we feel it’s a genuine and worthwhile possibility.
The total cost of any NYC condo or co-op renovation depends on existing site conditions, design preferences, level of finishes, and the actual scope of the project. As a general 2026 benchmark, a full upper mid-tier co-op or condo renovation in NYC ranges from $400 to $550 per square foot, inclusive of all labor and materials under a full-service design-build scope. Luxury renovations typically start at $550 per square foot and can reach $850 per square foot or more depending on finish level, custom millwork, and the extent of layout changes.
These ranges apply to full apartment renovations. Individual room renovations carry a higher cost per square foot because of fixed costs and trade minimums that get spread across a smaller scope.
Where The Numbers Move Within That Range
A handful of conditions and scope decisions reliably push a co-op renovation above the upper mid-tier baseline. The most common in our work across Manhattan and Brooklyn:
Pre-War Status: $600+ per square foot. Plaster walls, original framing, aging mechanical systems, and the level of period-specific restoration the apartment warrants all add scope. Pre-war co-ops also tend to involve more invasive electrical and plumbing rework once walls are opened.
Estate Condition: $600+ per square foot. Apartments that have not been touched in decades almost always require a full gut. The starting point is closer to a complete reset than a renovation, which is why estate-condition co-ops typically begin above the upper mid-tier ceiling.
Layout Changes: $550+ per square foot minimum. Moving walls, relocating plumbing, or reconfiguring rooms adds DOB filings, structural coordination, and trade complexity that pushes projects past the baseline range, often into luxury territory depending on the scope of the change.
Brownstones And Townhomes: $700+ per square foot. Larger systems, more square footage to coordinate, additional permits, and hidden conditions specific to older row houses move these projects into their own tier.
Cost Scenarios
NYC Co-Op Renovation Cost By Apartment Size And Scope
Source: Gallery KBNY 2026 NYC apartment renovation cost framework, Manhattan and Brooklyn. Per-square-foot ranges inclusive of labor and materials under a full-service design-build scope. Adding central air or true HVAC is a separate lump-sum scope item that typically adds $50,000 to $100,000 depending on system size and routing complexity. Brownstones and townhomes start at $700+ per square foot due to larger systems and hidden conditions.
Adding Central Air Or True HVAC
Adding central air or full HVAC to a NYC co-op renovation is a separate scope item rather than a per-square-foot adjustment. The work involves ductwork, condenser placement, additional electrical capacity, and almost always requires board approval and DOB filing. Most projects fall between $50,000 and $100,000 in added cost, depending on system size, routing complexity, and whether existing chases can be reused.
Carrying And Temporary Housing Costs
Beyond the construction estimate, factor in carrying costs and temporary housing for the duration of the project. Most full co-op renovations require three to six months of relocation depending on complexity and building work-hour restrictions. Carrying costs accumulate quickly when overlapping with a mortgage on the renovated unit, so we provide a detailed construction schedule early in planning so clients can arrange accommodations and storage with appropriate lead time.
Permits, Filings, And Building Fees
Permits and architectural filings for a NYC co-op renovation can run upwards of $30,000 in aggregate. Plumbing permits alone can reach $5,000, electrical permits typically cost about $900, and asbestos inspections add another $500 to $1,500 when required. Co-op-specific fees also add up: common area protection, elevator reservation, after-hours work charges, and certificate of insurance riders are all typical line items. We handle the full filing and approval process in-house at no separate fee, including alteration agreement coordination with the building's managing agent and reviewing architect.
Considering a Renovation in NYC?
Click to schedule a consultation with one of the principle partners at Gallery, who will hear out your renovation plans and let you know the best way to proceed - whether we end up working together or not.
[#Choosing]Choosing A Contractor For Your NYC Co-Op Renovation[#Choosing]
When renovating a co-op in NYC, there are various routes you can go - each with their own advantages. See how our design-build approach compares to competitive renovation models:
Design-Bid Firm Vs Design-Bid-Build Firm
A true design-build firm like Gallery offers a full-service renovation package for clients who value a partner with one main point of contact to oversee the entire process. Alternatively, a design-bid-build firm delivers a more piecemeal approach that allows for more flexibility, but essentially makes the client a project manager. Read a more detailed breakdown of the two approaches via Design-Build vs Design-Bid-Build: What’s The Difference?
Design-Build Firm Vs Architect
When taking on a full apartment renovation, the traditional approach has been to hire an architect, who draws up plans and handles the design work. They then bid out those plans to various contractors. The architect will act as your agent, often managing project construction too. This does not come without fees, as architects typically charge an additional 20% of the construction price to manage the contractors.
Design-build firms, on the other hand, offer a similar approach - without having to bid out plans to multiple contractors AND without the added 20% architects charge. With a design-build firm like Gallery, everything is done in-house. Our architect draws up the plans while the design team handles the space planning, finish and fixture component of the project, then our team does the build and construction - all overseen by our in-house project manager and construction manager, who ensure all finer points meet your specific expectations. We design the project, and then we build the project.
Delivery Model Comparison
How Each Co-Op Renovation Approach Compares
Comparison Point
Design-Build Firm
Design-Bid-Build
Architect-Led
Points Of Contact
One firm, one contract, one project lead from concept through closeout.
Designer, architect, contractor, and any specialty trades all contracted separately.
Architect leads, contractor and trades managed under a separate contract.
Who Manages Construction
In-house project manager and construction manager within the same firm as the design team.
Client acts as the de facto project manager between independent vendors.
Architect typically manages the contractor on the client's behalf.
Architect Fee Structure
Architectural services bundled into one fee, no separate construction-management add-on.
Architect fee paid separately, often hourly or as a percentage of plans.
Architect typically charges around 20% of construction cost to manage trades.
Pre-Construction Planning
Integrated. Site assessment, electrical and plumbing inspections, and board strategy happen before pricing is finalized.
Bid-driven. Each contractor prices the same plans, so unforeseen conditions are typically priced as change orders mid-project.
Architect plans, contractor prices. Less integrated coordination on infrastructure surprises.
Change Order Frequency
Low. Pre-construction integration catches most issues before demo.
Moderate to high. Gaps between plans and execution surface mid-project.
Variable. Depends on architect's construction-administration depth.
Board Approval Handling
Alteration agreement, DOB filings, and board engineer responses managed in-house at no separate fee.
Client coordinates submissions across architect and contractor; gaps create board revisions.
Architect typically handles board submissions; contractor coordination varies.
Best Fit For
Owners who want a single accountable team, predictable budget, and minimal client-side coordination on a complex co-op.
Owners with strong project-management experience and time to actively coordinate.
Owners working with an established architect relationship and a defined construction budget.
Source: Gallery KBNY delivery model framework, Manhattan and Brooklyn co-op renovations (2026).
With so many variables to consider when renovating your condo or co-op, hiring a knowledgeable full-service design-build firm in NYC that can successfully streamline all the moving parts is vital to a successful end result. At Gallery, we strive to continually provide the best client experience possible via the following core principles:
Board Approval And Permit Pros
We take on the responsibility of handling all red tape involved in co-op renovations in NYC, at no additional cost. This includes reviewing and satisfying a board’s alteration agreement, filing all relevant architectural plans with the Department Of Buildings, and procurement of all necessary permits.
Extensive Planning To Avoid Unexpected Costs & Change Orders
With a full-service team of design and construction professionals experienced in the complexities of NYC co-op renovations, our all-inclusive design-build approach makes change orders and mid-project budget adjustments much less likely.
Constant, Clear Communication
One of our core principles is keeping an open line of communication. We do this by offering regular site visits and phone calls, plus a mobile project management app to track all the steps of the job, material selections or questions, and anything else to discuss. You know what we know, every step of the way.
Gallery KBNY is an award-winning, full-service design-build firm specializing in the architecture, design, and renovation of apartments, co-ops, condos, townhomes, and lofts across Manhattan and Brooklyn. Our in-house team — with a founding partner involved in every project — manages every phase from board approvals through construction. No outsourcing, no handoffs, no gaps in accountability.
As seen in
Forbes|The New York Times|Architectural Digest|Inc.|Houzz
★★★★★100+ Five-Star ReviewsBest of Design & Service · 7 Years Running
Pre-Purchase Assessment
We conduct pre-purchase renovation assessments for buyers during the contract period. Walk the apartment with us before you commit — understand the full scope, cost, and timeline before closing.
Avi Zikry is the CEO and managing partner of Gallery KBNY, a full service design-build firm specializing in the design and interior renovation of apartments, townhomes, and lofts in NYC. Under his leadership, Gallery KBNY has earned the reputation for delivering exceptional service and beautiful homes to our select group of clients. Avi's strategic positioning extends beyond the brand. He has strategically cultivated a network of industry partners and suppliers, forging strong alliances that allow Gallery KBNY to access cutting-edge technologies and materials. By staying abreast of industry trends and technological advancements, Avi ensures the firm remains at the forefront of innovation, consistently offering clients the latest design solutions and construction methodologies.