The advantage of mortised lock sets is that they will last longer, lever handles won't sag and they offer many more latch/lock functions since the latch bolt and dead bolt are in the same housing and can even be operated together by turning the handle which is why they are standard for schools, hospitals and hotels. For a residential entrance door a mortise set can be set to lock automatically with a button in the door edge rather than in the center of the interior handle (ugh). One style is no more difficult to install than the other if you know how to do it and own the proper equipment. You should be able to buy the door already cut for either set unless you are buying it out of existing stock from a retail store so it is best to deal with a distributor perhaps through a contractor.

"how can I figure this out before ordering?" you purchase one and see if it operates smoothly, then stop worrying about it. It is just a lock There area number of methods for installing mortise locks, none of them 'low cost' since they all take a certain amount of skilled labor and somewhat expensive tooling to not damage the door. you can fit them with hand tools at a large price in labor This is one of the reasons the newer locks are just bored round holes. A couple hole saws, a small router, and some jigs and you can fit out the doors in about 15-20 minutes each. Even bolt and strike plates often come with rounded corners to allow quick routing of the shallow recess in the edge of the door and the jamb 9and there are also small tools available to square the corners if you do not like the rounded ones or the lock needs square corners). I have a hollow chisel mortiser (it 'drills' square holes) that can be used to bore for mortise locks, and have used it for this a number of times over the years. It runs about $1,000 minimum for good one. The small wood-shop ones are not adequate for the task since they do not move the chisel but force you to move the object being bored. OK fora small piece of wood for furniture making, not so good for a door. As long as there s away to unlock the door from inside the room easily without a key (thumb latch) the AHJ should not have a complaint. Privacy locks are standard for bedrooms and bathrooms, as opposed to passage knobs that cannot be secured at all.

We have a rim lock on one of our exterior doors, supplemented by a deadbolt. We have an old house, and there was what I guess was the original rim lock there when we bought the house, but it had no keeper. To replace it, I got one of the more ornate rim locks with keeper from HOAH. What I discovered was that the door frame wasn't on the same plane as the door, so I had to affix a piece of wood to bring the keeper in line with the latch. Also, the doorframe didn't seem to have enough wood behind it where the keeper needed to go, so the screws holding the keeper kept coming loose. I solved this by affixing the aforementioned piece of wood further way from the edge of the doorframe. So this is a long way of saying that you would need to let your contractor know that the doorframe needs to be able to accomodate the keeper. Also, if you live in a cold climate, you'll want to get draft covers for your keyholes. Here is a link that might be useful: Draft cover

I've got a 1905 home and have been adding new mortise locksets on the new interior doors - I know the hunt to find the right hardware. There are two companies that make high quality interior mortise locksets that I've found - Nostalgic Warehouse is one and the other is Emtek. Both brands are carried at House of Antique Harware online. Rejuvention (http://www.rejuvenation.com/) also sells one of the brands - I believe the NostalgicWarehouse ones - and you can customize for interior privacy, dummy, etc and choose finish, knob, locking type (latch, key) backplate. But the price reflects that ($150-ish per set). Some other sites carry the Nostalgic Warehouse hardware and you should search for that online once you figure out what backplate style you need at a cheaper price. For bathrooms, I prefer the latch type without the keyhole, it's easier than inserting a skeleton key. In the end -- $100+ for each set was cost prohibitive for me since I'm doing a complete remodel and an addition so continued searching and lucked out finding the "Prime Line" series at Homedepot.com at around $30 a set. Yes, there is a difference in quality, but it's what I could afford at the moment so it's worked ok so far. They are all skeleton keys and I've got the keys hanging on the knobs with ribbon like others have mentioned. Here's a picture of my new doors and the Prime Line set with my Dad testing it after he mortised it out. This post was edited by kjo_tx on Thu, Jul 11, 13 at 10:53