An ALT2 filing is the traditional name for a New York City Department of Buildings (DOB) alteration application covering several types of work that do not change a building's use, egress or occupancy. A New York State registered architect or licensed professional engineer files it. Today it is submitted in DOB NOW: Build under the job type "Alteration." This guide explains what qualifies, who files, what you need on hand and how mechanical, plumbing and fire protection scope shapes the process.
TL;DR
- ALT2 means an alteration with multiple types of work (for example plumbing, mechanical and construction together) that leaves use, egress and occupancy unchanged.
- In DOB NOW the old ALT2 and ALT3 labels collapse into one "Alteration" job type, but practitioners still say "ALT2" as shorthand.
- Only a registered design professional (a Registered Architect or Professional Engineer) can act as Applicant of Record and file it.
- Licensed trade work, such as oil burner or specialized plumbing work, can carry its own permit and license requirements on top of the filing.
- Filing without the right permit risks violations and fines, so scope the work before anyone swings a hammer.
Table of Contents
- What an ALT2 filing actually is
- ALT2 compared with ALT1, ALT3 and New Building filings
- What changed with DOB NOW
- Who is allowed to file
- Documents you will need
- From submission to permit: the process
- How MEP and fire protection work affects the filing
- Fees, inspections and sign-off
- Our perspective: where ALT2 filings go wrong
- Let us handle the filing and the engineering
- Mistakes that slow an ALT2 filing
- FAQ
What an ALT2 filing actually is
The DOB sorts alteration work by how much it changes the building. An Alteration Type 2 covers renovations that combine more than one kind of work but do not change the building's use, its means of egress (exits) or its type of occupancy. The DOB's own examples include adding a new bathroom, rerouting gas piping while adding electrical outlets, or moving a load-bearing wall.
That makes ALT2 the workhorse filing for ordinary commercial and residential renovation: a tenant fit-out where partitions, lighting, ductwork and sprinkler heads all move, a kitchen and bath gut renovation in a co-op, a boiler room upgrade that also touches gas piping and ventilation. If your project mixes trades, and the building will still be used and exited the same way afterward, ALT2 is almost certainly the category you are in.
The key phrase is "multiple types of work." One discipline, such as replacing a single plumbing fixture layout, usually falls into the lighter category. Several disciplines touching one another usually do not.
ALT2 compared with ALT1, ALT3 and New Building filings
The DOB describes the filing types by what they do to use, egress and occupancy. Here is the practical breakdown.
| Filing type | What it covers | Changes use, egress or occupancy? |
|---|---|---|
| New Building (NB) | Construction of a new structure | Not applicable, it is a new building |
| ALT1 | Major alterations | Yes, at least one changes |
| ALT2 | Multiple types of work | No |
| ALT3 | One type of minor work | No |
A useful test: ask what the building will be after the work. If a warehouse floor becomes residential, or an exit stair moves, you are in ALT1 territory, which usually means a new or amended Certificate of Occupancy. If the building stays what it is and the work spans trades, think ALT2. If it is a single, small scope, think ALT3.
Borderline cases exist. An extensive renovation can be so large that the DOB expects a new-building application instead, so a design professional should confirm the category before drawings are finished, not after.
What changed with DOB NOW
The DOB moved most filings out of the old paper and BIS-era process and into DOB NOW: Build. Under that system, the old ALT2 and ALT3 labels both map to a single job type called Alteration, and ALT1 and NB remain distinct. You will still hear architects, expediters and engineers say "we are filing an ALT2," and it still communicates something useful: substantial work, several trades, no change to the Certificate of Occupancy.
The practical consequence is that the portal asks you to describe work types within the application rather than choose an ALT2 button. Each work type you select, such as general construction, plumbing, mechanical or sprinklers, drives which forms, signoffs and inspections attach to the job. Getting those selections right at the start prevents objections later.
Some jobs are not professionally certified and are filed through a DOB borough office. The DOB's HUB services allow design professionals to submit applications and plans electronically and to collaborate with the Department through virtual plan review. Which route applies depends on the job, so confirm with your filing professional.
Who is allowed to file
An ALT2 is not a do-it-yourself filing, and a contractor cannot file it. The registered design professional, a New York State Registered Architect or Professional Engineer, serves as the Applicant of Record. That person submits the application, the drawings and the supporting documents to the DOB, and takes professional responsibility for the design's code compliance.
Who should be your Applicant depends on the work:
- Mostly architectural scope (layout changes, finishes, egress): typically an architect.
- Mostly systems scope (boilers, HVAC, plumbing, sprinklers, fire alarm): typically a professional engineer, often with the architect coordinating.
- Mixed scope: either can be the Applicant, with the other discipline filing or signing off on its own portion.
Owners carry responsibility too. The DOB is clear that property owners are ultimately responsible for keeping their property safe during construction and for making sure workers have appropriate safety training. Hiring a filer does not transfer that duty.
Documents you will need
There is no single universal checklist. The required documents depend on the scope of work and are listed inside the DOB NOW application itself. What you can count on is the timing structure the DOB uses:
- Prior to Filing: documents that must be uploaded before the application can be submitted.
- Prior to Approval: documents that can be uploaded later, including during the objections phase.
In practice, assemble these before you start:
- Property information: block and lot, owner details, and a current look at the building's record, including its Certificate of Occupancy.
- Drawings: existing conditions and proposed work, with plans, sections and schedules at the level of detail the scope demands.
- Systems drawings: mechanical, plumbing, sprinkler and fire alarm layouts, with riser diagrams and equipment schedules where applicable.
- Energy code documentation: compliance forms and calculations for the work, particularly for HVAC, lighting and envelope scope.
- Owner authorization and contractor information: who is performing the work and under which licenses.
- Special inspection and testing details: if the scope calls for them.
Missing or inconsistent documents are the most common reason for early objections. Treat the portal's document list as the source of truth for your specific job.
From submission to permit: the process
The flow is electronic from start to finish.
- Define the scope. List every type of work. This decides the filing type and the signoffs attached.
- Prepare drawings and calculations. Your design professional coordinates architectural and MEP/FP sheets so they do not contradict each other.
- File the job in DOB NOW: Build. The Applicant uploads the application and required documents.
- Department review. A plan examiner reviews the filing. If there are objections, the Applicant responds and resubmits online.
- Approval. Once the plans are approved, the permit request is submitted online.
- Permit issuance. After review and issuance, stakeholders can print the permit through the portal.
- Construction, inspections and closeout. Work proceeds, inspections occur, and the job is signed off.
Objections are normal, not a sign of failure. Plan for at least one round, and make sure the person responding understands both the code and the construction reality.
How MEP and fire protection work affects the filing
Mechanical, plumbing and fire protection scope is where ALT2 filings get complicated, because several parties can hold a piece of the permit.
Plumbing. Ordinary plumbing work may not require a permit, but ordinary maintenance and repair must still be performed by a Licensed Master Plumber (LMP) or, for oil burner equipment, a Licensed Oil Burner Installer. Work that goes beyond the limited plumbing scope requires permit documents submitted by a registered design professional. Permits themselves are issued to registered trade license holders.
Boilers and fuel storage. Certain boiler or fuel-storage work requires a specialized licensed professional. If you are replacing a boiler as part of a larger renovation, the engineering, the installer's license and the filing all need to line up. Our building owner services cover boiler and HVAC plant upgrades from evaluation through filing.
HVAC. New or relocated ductwork, rooftop units, ventilation changes and heat pump conversions generally sit inside the Alteration filing with mechanical work selected, and they trigger energy code review.
Fire suppression. Sprinkler relocations or additions that follow partition changes are classic ALT2 companions. They need engineered hydraulic design and coordination with FDNY requirements where applicable.
Emergencies. Licensed contractors may perform work that would normally need a permit before obtaining one when it relieves an emergency condition, but the application must be submitted within two business days after work begins. That is an exception for real emergencies, not a scheduling shortcut.
Fees, inspections and sign-off
Filing fees vary with the job, so check the DOB's current fee schedule rather than relying on a rule of thumb. One concrete number from the NYC Energy Conservation Code guidance: the Energy Review fee for Alteration filings other than 1-, 2- or 3-family homes is $525.
During construction expect:
- Progress inspections. TR8 energy progress inspections remain required during construction.
- Special inspections. If your scope requires them, hire a Special Inspection Agency and notify the Department online before pulling the permit.
- Commissioning. For systems that require it, commissioning takes place after installation of the systems is complete, and it must be filed with the DOB before sign-off.
- Final sign-off. The contractor completes the DOB inspections and obtains sign-off. Closeout is where jobs stall when paperwork has been left until the end.
The cost of skipping the process is steep. The DOB warns that work without proper permits is unsafe, can bring fines of up to $25,000 for Class 1 violations, and can lead to criminal court proceedings.
Our perspective: where ALT2 filings go wrong
We have filed and engineered enough alteration jobs across New York City, Long Island and Westchester to see the same patterns repeat. The filing type is rarely the problem. The trouble starts when the systems design arrives late.
A kitchen, bathroom or tenant layout gets drawn first, and only then does someone ask where the gas riser, the exhaust path or the sprinkler branch lines will go. The architectural plans are then reopened, the objections pile up, and the schedule slips. When mechanical, electrical, plumbing and fire protection are designed together, by engineers in the same office, those conflicts surface on paper instead of in the field.
Our advice to owners and property managers: bring the engineer in at scope definition, not after the architect's drawings are set. Ask who will actually answer your questions. At our firm you work directly with senior engineers, not account managers, and that shortens the loop between a DOB objection and a corrected sheet.
For contractors and installers: confirm early which parts of the job sit under your trade license and which require a filed design. It is much cheaper to learn that before the permit request than at inspection.
— Joseph
Let us handle the filing and the engineering
If you are an owner, manager, architect or contractor with an alteration on the horizon, our team prepares the MEP/FP design and files with the DOB, coordinating with agencies such as FDNY along the way. We are licensed in New York and Florida and have been doing this since 2010.
See our NYC permit filing service or browse all engineering services to find the discipline you need. Pricing is set per project scope, so describe your project and we will tell you what it involves.
Mistakes that slow an ALT2 filing
- Choosing the wrong job type. Changing egress or occupancy pushes you into ALT1. Check this before drawings are developed.
- Late engineering. Systems added after architectural drawings are final create contradictory sheets and objections.
- Incomplete uploads. Not knowing which documents are due before filing and which before approval stalls the submission.
- Assuming the contractor can file. Only the registered design professional files the application.
- Ignoring trade licenses. Boiler, oil burner and plumbing work have licensed-holder requirements separate from the design filing.
- Leaving closeout for last. Inspections, special inspection reports and commissioning filings are easier to collect as the work progresses.
- Starting work early. Beyond genuine emergencies, work before the permit is issued invites violations.
FAQ
Does DOB NOW still have an ALT2 job type?
No. In DOB NOW the former ALT2 and ALT3 categories both appear as Alteration. Professionals still say ALT2 as shorthand for work involving multiple trades that does not change use, egress or occupancy.
Can I file an ALT2 myself as the building owner?
No. The application must be prepared and submitted by a New York State Registered Architect or Professional Engineer acting as Applicant of Record. As the owner you remain responsible for safe conditions on the property during construction.
Does a bathroom or kitchen renovation need an ALT2?
Often yes, when the work combines types such as plumbing, gas and electrical or moves walls. The DOB lists adding a new bathroom and rerouting gas pipes among its examples. Simple like-for-like work may not need one, so have a design professional review your scope.
What happens if I do the work without a permit?
You risk violations, fines of up to $25,000 for Class 1 violations, and potentially criminal court proceedings, according to the DOB. You may also face trouble at sign-off or sale. Legalizing work after the fact is usually harder than filing correctly first.
When can I start work after filing?
Work starts after the application is approved and the permit is issued, and the permit can then be printed from the portal. The only exception is emergency work by a licensed contractor, whose application must be submitted within two business days of starting.