LPC Window Approval Process: A Step-by-Step Guide
If your building is located in one of New York City’s historic districts or is designated as an individual landmark, you can’t just call up a window contractor and make an appointment for installation. The Landmarks Preservation Commission (LPC) has to review every window facing the street — and in many buildings, every window, period. If you don’t take this step, you could receive stop work orders, fines and be compelled to remove windows you’ve already paid to install.
The good news is that once you determine which of the LPC’s three permit tracks is right for your project, the approval process is well-defined. Here’s exactly how the process works in 2026, including the change to LPC’s Portico web portal, what influences your timeframe and the specific processes that keep a routine window replacement from stretching into a six-month endeavor.
LPC Window Approval Process : Quick Answer
LPC window approval requires filing one of three permit types through the Portico portal: a Certificate of No Effect (CNE), a Permit for Minor Work (PMW), or a Certificate of Appropriateness (CofA). Most in-kind window replacements qualify for staff-level review as a PMW, typically decided in 20–30 business days. Projects that change a window’s size, material, or visual profile usually require a CofA, which involves a public hearing and can take two to six months. LPC approval must be secured before filing with the Department of Buildings — the two agencies do not process in parallel.
What is the LPC and when do you need their approval?
The New York City Landmarks Preservation Commission is the city agency responsible for designating and protecting buildings, interior spaces and historic districts of special architectural, historic or cultural significance. When a building is designated as a landmark, either as an individual landmark or as a contributing building in a historic district, the LPC has the power to review exterior changes visible from a public street and, in some cases, certain interior spaces that are protected.
That is exactly where window replacement lies in that authority. Windows are a “major architectural feature” because their material, dimensions, and glazing pattern contribute significantly to defining the character of a historic façade. That implies that if you want to replace existing windows in almost any landmarked structure, you need a permission, even if the Department of Buildings wouldn’t normally require a permit for the job.
Three Kinds of Window Work Permits for LPC
All LPC applications involving outside work, such as window replacement, fall into one of three tracks. Which one applies depends on how much the proposed work alters the building’s protected features and if it also requires a DOB permit.
1. Certificate of No Effect [CNE]
A CNE is for work that requires a DOB permit but does not impact any protected exterior features (e.g., internal renovations, rooftop mechanical equipment, or plumbing work behind an unaltered facade). LPC preservation officials assess and issue CNEs without a public hearing. LPC has 30 business days by law to decide a comprehensive CNE application, but simple applications with all required documentation are typically approved in around 10 business days.
2. Minor Work Permit (PMW)
This is the route most window replacement projects take. A PMW covers smaller scale external improvements to a protected feature, such as in-kind window or door replacement, that does not itself require a separate DOB permit. PMWs are also decided at the staff level, not pre-emptively before the whole Commission. The processing period for a complete application is normally 20 working days however this will depend upon the number of windows and whether a site visit is required.
3. Certificate of Appropriateness (CofA)
Proposed work that impacts protected characteristics and also requires a DOB permit, or that has had a denied PMW application, is required to get a CofA. This is the track for substantial changes — changing the size, material, operation or look of a window; creating a larger opening; or any work paired with major construction. A CofA needs a public hearing with the full eleven member Commission, and in many historic areas a presentation to the local community board prior to that. A full Commission review can take anywhere from two to six months, with the clock being reset if the Commission requests revisions and a second hearing.
Why LPC Window Approval Process Matters More in 2026
The practical experience of getting LPC approval has been revised twice in recent years. Firstly, all applications are now submitted via Portico, LPC’s web-based permit portal — the agency has done away with paper filings entirely and application status can be followed online at every stage. That has made the process more transparent but also increased the bar for documentation quality since incomplete Portico submissions are sent back for correction rather than clarified informally over the phone.
Second, energy-code pressure has collided with preservation rules in ways that didn’t exist a decade ago. With building owners seeking to meet Local Law 97 emissions regulations, window renovations are an expanding part of their compliance plan – but a landmarked building can’t just install new high-performance units without LPC sign-off on appearance. This puts early coordination between a building’s energy-compliance plan and its LPC filing at a premium, as they are related, but not the same application, and they don’t run on the same clock.
The Importance of Doing the Filing Right the First Time
Avoids stop-work orders and removal expenses
The DOB may issue a stop-work order for any installation of windows without the appropriate LPC approval, including even in-kind replacements. In enforcement instances, the non-compliant windows would have to be removed and the building restored to its former condition. That cost dwarfs the cost of filing it correctly up front.
Safeguards Your DOB Permit Timeline
You cannot submit a DOB permit application for work that impacts protected features until LPC approval has been granted. A denied or delayed LPC filing pushes everything downstream — the DOB permit, the contractor’s schedule and for occupied buildings, tenant notification timelines.
Maintains Property Value & Resale Potential
Unpermitted changes to a landmarked property constitute a title and resale concern, not just a compliance issue. Buyers’ lawyers will normally pick up any unresolved LPC breaches during due diligence.
Keeps Multi-Building Portfolios on a Steady Cycle
For property managers with multiple landmarked buildings, a repeatable LPC filing process creates a documented approach, instead of a one-time scramble, to maintain window replacement programs on schedule across a whole portfolio.
Common Errors for LPC Window Approval Process
Assuming full window replacement is a “repair” and not going through the LPC file at all.
- Filing with a DOB permit application before LPC approval is given – DOB will reject applications for LPC-jurisdiction work that are filed out of sequence.
- Submitting drawings without exact existing-condition dimensions, which almost assures a request for revision.
- Selecting a replacement window with an energy performance rating, but not verifying that its visual profile will meet LPC review standards.
- “Field substitution of material or color after approval provided it is close enough to what was approved.
- Waiting to engage a contractor knowledgeable in LPC filings until after a self-prepared application has been turned down.
Pros & Cons of In-Kind Replacement vs. Full Redesign
In-Kind Replacement (match existing)
Full Redesign (new material/profile)
Approval Track
Usually PMW — faster, staff-level
Usually CofA — public hearing required
Typical Timeline
~20 working days
2–6+ months
Design Flexibility
Limited — must match existing profile/material
High — subject to Commission approval
Energy Performance Options
Constrained to compatible materials/finishes
Broader range of high-performance glazing options
Approval Certainty
High — well-established review criteria
Lower — subject to Commissioners’ judgment and hearing outcome
Best Suited For
Routine replacement cycles, budget-conscious projects, portfolios with many units
Full facade renovations, adaptive reuse, buildings pursuing major energy retrofits
FAQ
1.Do all windows in a landmarked building need LPC approval, or just street-facing ones?
Depends on the building. Primary facades on a public thoroughfare nearly always require assessment. Also, many historic districts look at rear and side facades especially if they are seen from another public way. The designation report for your building will identify which facades are protected.
2.How long does LPC window approval take?
Most in-kind window replacements fall under the track of a Permit for Minor Work which usually takes around 20 working days from when the application is complete. You will need a Certificate of Appropriateness for more major adjustments, which usually takes about 90 working days, and can take longer if amendments are necessary.
3.Can I replace a broken window pane without LPC approval?
Yes. You don’t need an LPC permit for everyday repairs, such as repairing broken glass, re-caulking, repainting to match current color, etc. This is not a full window replacement.
4.What is Portico?
Portico is the web-based permit application portal for LPC. All LPC applications including Certificates of No Effect, Permits for Minor Work and Certificates of Appropriateness are now filed and tracked through Portico instead of on paper.
5.Does LPC approval need to happen before or after my DOB permit?
Before. LPC approval is required. The Department of Buildings will not accept an application for a permit for work under LPC jurisdiction until the LPC approval has been obtained.
If your building is located in one of New York City’s historic districts or is designated as an individual landmark, you can’t just call up a window contractor and make an appointment for installation. The Landmarks Preservation Commission (LPC) has to review every window facing the street — and in many buildings, every window, period. If you don’t take this step, you could receive stop work orders, fines and be compelled to remove windows you’ve already paid to install.
The good news is that once you determine which of the LPC’s three permit tracks is right for your project, the approval process is well-defined. Here’s exactly how the process works in 2026, including the change to LPC’s Portico web portal, what influences your timeframe and the specific processes that keep a routine window replacement from stretching into a six-month endeavor.
LPC Window Approval Process : Quick Answer
LPC window approval requires filing one of three permit types through the Portico portal: a Certificate of No Effect (CNE), a Permit for Minor Work (PMW), or a Certificate of Appropriateness (CofA). Most in-kind window replacements qualify for staff-level review as a PMW, typically decided in 20–30 business days. Projects that change a window’s size, material, or visual profile usually require a CofA, which involves a public hearing and can take two to six months. LPC approval must be secured before filing with the Department of Buildings — the two agencies do not process in parallel.
What is the LPC and when do you need their approval?
The New York City Landmarks Preservation Commission is the city agency responsible for designating and protecting buildings, interior spaces and historic districts of special architectural, historic or cultural significance. When a building is designated as a landmark, either as an individual landmark or as a contributing building in a historic district, the LPC has the power to review exterior changes visible from a public street and, in some cases, certain interior spaces that are protected.
That is exactly where window replacement lies in that authority. Windows are a “major architectural feature” because their material, dimensions, and glazing pattern contribute significantly to defining the character of a historic façade. That implies that if you want to replace existing windows in almost any landmarked structure, you need a permission, even if the Department of Buildings wouldn’t normally require a permit for the job.
Three Kinds of Window Work Permits for LPC
All LPC applications involving outside work, such as window replacement, fall into one of three tracks. Which one applies depends on how much the proposed work alters the building’s protected features and if it also requires a DOB permit.
1. Certificate of No Effect [CNE]
A CNE is for work that requires a DOB permit but does not impact any protected exterior features (e.g., internal renovations, rooftop mechanical equipment, or plumbing work behind an unaltered facade). LPC preservation officials assess and issue CNEs without a public hearing. LPC has 30 business days by law to decide a comprehensive CNE application, but simple applications with all required documentation are typically approved in around 10 business days.
2. Minor Work Permit (PMW)
This is the route most window replacement projects take. A PMW covers smaller scale external improvements to a protected feature, such as in-kind window or door replacement, that does not itself require a separate DOB permit. PMWs are also decided at the staff level, not pre-emptively before the whole Commission. The processing period for a complete application is normally 20 working days however this will depend upon the number of windows and whether a site visit is required.
3. Certificate of Appropriateness (CofA)
Proposed work that impacts protected characteristics and also requires a DOB permit, or that has had a denied PMW application, is required to get a CofA. This is the track for substantial changes — changing the size, material, operation or look of a window; creating a larger opening; or any work paired with major construction. A CofA needs a public hearing with the full eleven member Commission, and in many historic areas a presentation to the local community board prior to that. A full Commission review can take anywhere from two to six months, with the clock being reset if the Commission requests revisions and a second hearing.
Why LPC Window Approval Process Matters More in 2026
The practical experience of getting LPC approval has been revised twice in recent years. Firstly, all applications are now submitted via Portico, LPC’s web-based permit portal — the agency has done away with paper filings entirely and application status can be followed online at every stage. That has made the process more transparent but also increased the bar for documentation quality since incomplete Portico submissions are sent back for correction rather than clarified informally over the phone.
Second, energy-code pressure has collided with preservation rules in ways that didn’t exist a decade ago. With building owners seeking to meet Local Law 97 emissions regulations, window renovations are an expanding part of their compliance plan – but a landmarked building can’t just install new high-performance units without LPC sign-off on appearance. This puts early coordination between a building’s energy-compliance plan and its LPC filing at a premium, as they are related, but not the same application, and they don’t run on the same clock.
The Importance of Doing the Filing Right the First Time
Avoids stop-work orders and removal expenses
The DOB may issue a stop-work order for any installation of windows without the appropriate LPC approval, including even in-kind replacements. In enforcement instances, the non-compliant windows would have to be removed and the building restored to its former condition. That cost dwarfs the cost of filing it correctly up front.
Safeguards Your DOB Permit Timeline
You cannot submit a DOB permit application for work that impacts protected features until LPC approval has been granted. A denied or delayed LPC filing pushes everything downstream — the DOB permit, the contractor’s schedule and for occupied buildings, tenant notification timelines.
Maintains Property Value & Resale Potential
Unpermitted changes to a landmarked property constitute a title and resale concern, not just a compliance issue. Buyers’ lawyers will normally pick up any unresolved LPC breaches during due diligence.
Keeps Multi-Building Portfolios on a Steady Cycle
For property managers with multiple landmarked buildings, a repeatable LPC filing process creates a documented approach, instead of a one-time scramble, to maintain window replacement programs on schedule across a whole portfolio.
Common Errors for LPC Window Approval Process
Assuming full window replacement is a “repair” and not going through the LPC file at all.
- Filing with a DOB permit application before LPC approval is given – DOB will reject applications for LPC-jurisdiction work that are filed out of sequence.
- Submitting drawings without exact existing-condition dimensions, which almost assures a request for revision.
- Selecting a replacement window with an energy performance rating, but not verifying that its visual profile will meet LPC review standards.
- “Field substitution of material or color after approval provided it is close enough to what was approved.
- Waiting to engage a contractor knowledgeable in LPC filings until after a self-prepared application has been turned down.
Pros & Cons of In-Kind Replacement vs. Full Redesign
| In-Kind Replacement (match existing) | Full Redesign (new material/profile) | |
|---|---|---|
| Approval Track | Usually PMW — faster, staff-level | Usually CofA — public hearing required |
| Typical Timeline | ~20 working days | 2–6+ months |
| Design Flexibility | Limited — must match existing profile/material | High — subject to Commission approval |
| Energy Performance Options | Constrained to compatible materials/finishes | Broader range of high-performance glazing options |
| Approval Certainty | High — well-established review criteria | Lower — subject to Commissioners’ judgment and hearing outcome |
| Best Suited For | Routine replacement cycles, budget-conscious projects, portfolios with many units | Full facade renovations, adaptive reuse, buildings pursuing major energy retrofits |
FAQ
1.Do all windows in a landmarked building need LPC approval, or just street-facing ones?
Depends on the building. Primary facades on a public thoroughfare nearly always require assessment. Also, many historic districts look at rear and side facades especially if they are seen from another public way. The designation report for your building will identify which facades are protected.
2.How long does LPC window approval take?
Most in-kind window replacements fall under the track of a Permit for Minor Work which usually takes around 20 working days from when the application is complete. You will need a Certificate of Appropriateness for more major adjustments, which usually takes about 90 working days, and can take longer if amendments are necessary.
3.Can I replace a broken window pane without LPC approval?
Yes. You don’t need an LPC permit for everyday repairs, such as repairing broken glass, re-caulking, repainting to match current color, etc. This is not a full window replacement.
4.What is Portico?
Portico is the web-based permit application portal for LPC. All LPC applications including Certificates of No Effect, Permits for Minor Work and Certificates of Appropriateness are now filed and tracked through Portico instead of on paper.
5.Does LPC approval need to happen before or after my DOB permit?
Before. LPC approval is required. The Department of Buildings will not accept an application for a permit for work under LPC jurisdiction until the LPC approval has been obtained.
