Building Codes and Inspections/Door threshold


We have an apartment in Richmond BC which is 6 years old. All the apartment entrance doors have a gap of about 1.5 inches under them. In the winter we get a terrible draft under the door and have to put something in front of the gap. We have also seen a mouse come under the door and recently we had a bad moth problem which meant throwing out our wool rug. Is it standard to build without a threshold. If we were to put a threshold in place would it interfere with the air circulation in the building?
Thank You

Hi Kathleen -

Sorry for the delay in responding to your question.  It is unusual for clearance under the door to be required for air circulation or HVAC, and it is not typical to have an entrance door without a threshold.  If a door is required to be accessible, the threshold height would be limited to 1/2-inch maximum, but you could add a threshold on the floor and a door sweep mounted on the door to seal the gap.  It doesn't sound like your door is fire rated, but if it was, the clearance under it would be limited to 3/4-inch and the threshold and sweep would have to be certified for use on a fire door.

- Lori

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Lori Greene


I can help with code questions related to doors and hardware. I am familiar with the IBC, NFPA 80, NFPA 101, NFPA 105, ADAAG, and ICC/ANSI A117.1. My expertise is specific to door openings.


I have worked in the door and hardware industry since 1986. I have conducted countless presentations on code requirements for doors and hardware, and maintain a blog related to doors and hardware (

Door & Hardware Institute (DHI) Construction Specifications Institute (CSI) National Fire Protection Association (NFPA) International Code Councel (ICC)

Doors & Hardware Magazine

Vermont Technical College, Associate Degree in Architecture and Building Engineering Technology - 1986

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