Busse's Lock Service, LLC: 
                        2003 Wake Forest Rd, Raleigh, NC 27608

Old mortise locks -- modernize or restore

by Laura Busse April 06, 2012

So your house is 40-100 years old or more, and the exterior door still has the original lock with a “pitcher handle.”  The keyhole is above the handle and operates both the latch and the deadbolt.  Or rather, it did until it broke down.  In some cases the lock can be repaired.  However, at a certain point it’s finally time to replace the lock.  Exact replacements are not available for old locks such as this, so there will be some modifications to the door no matter what.  There are three options that you have:
1. New Door.  If your door is cracked, sagging or just plain ugly, now is the time to replace it.  Don’t spend money on hardware for a door that is unsuitable.

2. Modernize.  Adapt the door to accept modern (cylindrical) lock hardware.  This option is less expensive than the other options, but any historic appeal the door had is sacrificed.  Still, this is a popular option for budget-conscious homeowners and landlords.
Old Mortise Lock interior Old Mortise Lock exterior    Modernized lock Modernized lock 2

This old mortise lock on an apartment lobby (subdivided house) was not working for the tenants (left).  The landlord needed reliable functionality, and cost was an important consideration.  This door was modernized and fitted with a storeroom function knobset (right).  A key is required to enter the door every time.

3. New Mortise Retrofit.  Replace the old mortise lock with a new one.  Locks that are identical in every dimension to the old lock are not available.  The new lock will surely need some new holes cut through the door.  Conversely, it will need to cover some leftover holes.  Choose a lock with a long backplate to cover most of these blemishes.  There may still be one hole (where the old handle attached at the bottom) that needs to be patched and painted.  This option is more expensive than modernizing, but it enhances the historic appeal of the door while providing the ease and reliability of a brand new lock.  Emtek offers mortise locks in every conceivable style and color.

New Mortise 1
The owners of this home had been struggling with a more-or-less broken door for a decade (left).  Finally, they took the plunge with a new Emtek mortise lock (right).  The long backplate on the new lock covers all the old holes except the small one at the bottom that needs to be patched and painted.   Now the door works just like brand new!