A.Finish carpenter Dave Frane responds:
The upper half of a Dutch door can be operated without opening the
lower half. Dutch doors are often seen in barns and
greenhouses, but they are also used by people who want to open
part of a door without allowing pets or small children to get
in or out of the room.
Odds are it's cheaper to buy a ready-made Dutch door than to
convert an existing panel on site. But if for some reason you
have to convert an existing door, first you'll need to figure
out where to split the door. The passage set goes in the lower
half, so you should cut the door a couple of inches above the
knob. You'll need to trim about 3/4 inch from the
height of the door to make room for stops between the halves.
The lower stop is mounted near the face that closes against the
jamb stops. The upper stop is mounted near the in-swing
If it's a solid-core door, you'll have to remove some of the
exposed particle-board core and replace it with a wood filler.
Ideally, you'd remove about an inch and replace it with a
glued-in wood strip. The best way to remove the core is with a
router and a straight or rabetting bit. A straight bit will cut
deeper, but a rabetting bit is easier to control because
there's no need to balance the router on the narrow edge of the
You can skip this step if you use a wood panel door. However,
you'll have fewer choices about where to split the panel
because you have to do it somewhere on the lock rail. Cut too
low and you crowd the passage set. Cut too high and the upper
half ends up with a skinny lower rail. To maximize the width of
the remaining rails, make room for the stops by trimming the
bottom of the lower half and dropping it lower in the jamb.
This means remortising the existing hinges, but you'd have to
do that anyway because the hinges need to be closer to the top
and bottom edges than normal. If they aren't, the short wide
door halves will sag in the jamb. Each panel will have two
hinges, and the halves will be tied together by a slide bolt on
the in-swing face of the door.
You should not convert a fire door to a Dutch door. There is
such a thing as a fire-rated Dutch door, but it has special
gasketing and has been designed and approved for the