In most of the country, replacing a door is a weekend project. In New York City, it rarely is. Pre-war walls that aren’t square, building management that wants paperwork before a contractor walks in, and freight elevators that need to be booked in advance can turn a simple swap into a small logistics exercise. Whether you’re replacing a warped closet door in a Queens co-op or upgrading the entry door of a Brooklyn brownstone, here’s what to know before you hire someone.

Why Door Installation Is Harder in New York

Much of the city’s housing stock is old. After decades of settling, many door openings are no longer plumb or square, so a standard pre-hung door often won’t drop neatly into place. An experienced installer will shim, trim, and sometimes rebuild part of the frame so the door swings freely, latches on the first try, and doesn’t drift open on its own. Pre-war apartments also tend to have non-standard opening sizes, which can mean ordering a custom slab instead of grabbing one off the shelf.

Then there’s the building itself. Most co-ops and condos require contractors to submit a certificate of insurance (COI) naming the building before any work begins. Many limit work to weekday hours and require elevator reservations. Entry doors have their own rules: most multi-unit residential buildings in the city require self-closing apartment entrance doors, and many must be fire-rated. Getting this wrong can mean redoing the job or failing an inspection.

Know Which Door You Need

Not every door project is the same, and it helps to know the basics before you request quotes:

Interior doors. Hollow-core doors are light and affordable. Solid-core doors cost more but block far more sound, which matters in apartments with thin walls. Closet doors. Bifold, sliding, and barn-style doors each suit different spaces. Sliding and barn doors are popular in small apartments because they don’t need swing clearance. Entry doors. These carry the most weight in security and code compliance. Ask about fire ratings, self-closing hardware, and lock compatibility.

Shower doors. Framed and frameless glass doors need precise measuring and proper sealing. A poor install leads to leaks, mildew, and a door that never quite closes.

Repair or Replace?

Not every problem calls for a new door. A sticking door can often be fixed by adjusting hinges or planing the edge. Replacement makes more sense when the door is warped, cr