New York City Homeowner's Guide -
Exterior doors should be of solid-core construction. Double doors need
good security because they are easily forced or jimmied. Flush lever
bolts should be installed at the top and the bottom. The bolt should
be long, sturdy and mounted into a solid doorframe. Doors with windows
or glass ornamentation require double key deadlock bolts. This prevents
the burglar from breaking the glass and reaching inside to unlock the
door. The key to a double key deadbolt lock should be left in at all
times when someone is home to ensure that the resident can escape in
the event of fire or other emergency.
Make sure that doorframes are solid and are equipped with proper strike
plates. Doors should be mounted so that hinge-bolts are not exposed
to the outside. Install a door eye-viewer.
Metal bars installed on basement windows provide extra security. Try
to use bars that can be opened from the inside in the event of fire
or other emergency.