A multi-point lock engages the door into the frame at three or more points along its height — usually top, middle, and bottom — instead of just at the handle. Impact-rated doors are tested as a full assembly under that multi-point engagement, so a standalone deadbolt wouldn't distribute wind load the way the door was actually rated to handle; the multi-point hardware is part of what earns the pressure rating, not just a security upgrade.

Yes — under enough pressure, a door that isn't engineered and hardware-rated for wind load can deflect, disengage from a standard lock, or fail at the hinges or frame connection, and once one exterior opening fails, wind pressurizes the inside of the house and puts much more stress on the roof and every other opening. This is a large part of why every exterior door on the house, not just the front entry, falls under the same code protection requirement as the windows.

Generally yes — the design pressure required is based on the opening's location on the building (elevation, corner, height), not whether it's a door or a window, so a door and an adjacent window in the same wall zone typically need comparable pressure ratings, even though the products and testing methods used to prove it look different.

Because the threshold is the part of the assembly most exposed to standing water and wind-driven rain during a storm, and it's also a structural anchor point. A door can carry the correct NOA rating on paper and still leak or underperform if the sill pan, flashing, and anchoring underneath it aren't installed correctly — the rating describes the tested product, not any possible installation of it.

Yes — double doors use an astragal, a vertical bar or strip between the two leaves that both doors lock into, usually through top and bottom bolts on the inactive leaf. The astragal is part of what makes a double door hold its rating, so it needs to be included and installed correctly rather than treated as an optional trim piece.

Both configurations exist and are used in Florida — swing direction is more often driven by interior clearance, egress requirements, and how the space is used than by the wind rating itself, since the door and frame are engineered as a system regardless of which way it swings. Your installer will confirm the swing direction works for both the opening and any egress requirement on that room.

The code trigger is permitted work, not age alone — you're not required to replace an existing door that's just sitting there, but once you pull a permit to replace it, it has to meet current impact/pressure requirements in HVHZ or WBDR counties. If the door predates the post-2002 HVHZ code overhaul, it was never tested to current standards at all, which is worth knowing for both storm performance and insurance documentation.

It's possible but has to be specified as part of the tested door assembly rather than cut into a rated door after the fact — cutting a factory opening into an already-rated door leaf voids its tested performance. If a pet door is important to you, tell us during product selection so we can source a door assembly designed and rated with that opening included.