Deadbolt, lever or handleset: choosing the right smart lock body

Someone who has settled on keyless entry usually expects the next decision to be a brand. What arrives instead is a shape question. The same lock family sits on the shelf as a squat round deadbolt, as a lever with a keypad on its outer face, and as a full-length handleset with a grip and a thumb piece. The prices are within a hundred dollars of each other, the box copy is close to identical, and none of it explains which one your door can take.

The three are not interchangeable. They hold a door shut by different means, they need different holes cut through it, and one of them is handed, which is the detail that turns a straightforward swap into a return trip to the store. Working out which body suits the door takes about five minutes with a tape measure, and it is worth doing before the card comes out rather than after.

This question lands immediately after you have picked a category. If you are still at the earlier stage, deciding between a mechanical pushbutton lock, a keypad deadbolt and a connected model, start with the five distinct types of keyless entry lock and come back to the body once the category is settled.

What the three bodies actually do

The deadbolt

A deadbolt is a bolt and a means of turning it, and nothing else. A thumbturn on the inside and a keyed cylinder or keypad on the outside drive a square-ended bolt out of the door edge and into a hole in the jamb. Residential bolts throw about an inch. There is no spring behind the bolt and no bevel on its face, so pressure against the door will not push it back. It moves only when something turns it.

What a deadbolt will not do is hold the door closed. That job belongs to the latch below it. A door with a deadbolt and nothing else swings open in the wind the moment the bolt is retracted, which is why deadbolts are almost always the second lock on a door rather than the only one.

The lever

A lever set is a latch with a handle attached. Push the door shut and the beveled face of the spring latch rides across the strike plate and drops into the hole behind it. Turn the lever from either side and the latch pulls back. A keyed or keypad lever adds a lock to the handle itself: the outside lever either spins freely or refuses to move until the right code goes in.

The number that matters is the throw. A standard latch projects about half an inch and its face is angled. That angle is what lets the door close without anyone touching the handle. It is also what a stiff plastic card slides along when somebody wants the door open without a key, a trick that works on a latch and does nothing at all against a bolt.

The handleset

A handleset is two locks under one exterior plate. A deadbolt at the top, a gripset below it with a thumb piece that presses down to pull the latch back, and on the inside a thumbturn or keypad trim above an interior lever or knob. It needs both bores in the door, spaced the way the maker expects, and it covers a tall strip of the door face. That last part is most of why people buy one.

Smart handlesets usually put the electronics in the deadbolt half and leave the grip and thumb piece mechanical. A keypad handleset is therefore a keypad deadbolt sold with matching trim and a latch set, which is worth knowing: the electronic behavior, the app, the code limits and the battery life are generally identical to the plain deadbolt version of the same model.

A smart lever is not a smart deadbolt

This is the substitution that catches the most people, because a keypad lever looks like it is doing the same job with less drilling and less money. On an exterior door it is not. A locked lever stops the handle turning; the latch it controls is still a half-inch sprung bolt with a beveled face sitting in a thin pressed strike plate. A deadbolt puts a solid inch of steel across the same gap with no spring and no bevel to work against.

Testing standards treat them as different products for that reason. Bored locks and deadbolts are graded under separate requirements, and the grade printed on a lever’s packaging describes handle strength and cycle counts rather than what the door resists at the bolt. The ANSI and BHMA grades are worth understanding before you compare two boxes, because the same number means different things on different hardware.

None of which makes keypad levers useless. It makes them the wrong sole lock on a front entrance, and a sensible choice on the door between a garage and a kitchen, on a home office, on a shared basement door, or on any exterior door that already has a deadbolt above it doing the security work.

The holes in your door decide most of this

Everything above is preference. What follows is arithmetic. Take a tape measure to the door before shortlisting anything.

• Backset. The distance from the door edge to the center of the bore. American residential doors use 2-3/8 inches or 2-3/4 inches. Most locks ship with an adjustable bolt or latch that covers both, but not all of them do, and a fixed-backset lock in the wrong size is a hard stop.
• Cross bore. The large hole through the face of the door, 2-1/8 inches on anything prepped in the last few decades. Older doors sometimes carry a 1-1/2 inch bore, which rules out most current hardware unless the hole is enlarged.
• Edge bore. The 1 inch hole drilled into the door edge that the bolt or latch assembly slides through.
• Door thickness. Usually 1-3/8 inches on interior doors and 1-3/4 inches on exterior ones. A thicker slab needs a longer tailpiece and screw kit, which some manufacturers sell separately and some do not offer at all for a given model.
• Center to center. On a door prepped for both locks, the vertical distance between the deadbolt bore and the handle bore. 5-1/2 inches is common, other spacings exist, and a handleset built for one will not sit over the other.

The pattern that falls out of this is simple. A deadbolt cares only about the upper bore. A lever cares only about the lower one. A handleset cares about both and about the distance between them, which is why it is the body most likely to arrive and not fit.

If the door has one bore and you want a deadbolt above it, that is a drilling job rather than a shopping problem. Read up on cutting a fresh deadbolt bore before committing, because there are door constructions where it should not be attempted at all.

Handing, and the box you have already opened

Deadbolts are not handed. The bolt goes straight out of the edge and has no opinion about which way the door swings, which is one reason the smart deadbolt and retrofit market is as large as it is: one part number fits every door in the street.

Levers are handed in principle and reversible in practice. Most residential lever sets can be flipped on the door, often by backing out a small screw and rotating the handle, and the instructions cover it in a paragraph near the end.

Handlesets are where it bites. The thumb piece, the interior lever and sometimes the trim itself are cut for one swing direction. Some models are reversible on the door and some are ordered as a left-hand or a right-hand item. Returning one that has been unpacked and part-assembled is a slower conversation than returning one still sealed, so this is the check to make before anything is opened. A French door pair adds a wrinkle, since only the active leaf is handed, as our smart lock for French doors guide explains.

Determining the hand takes ten seconds. Stand outside the door, on the side you would put a key into. If the hinges are on your right, it is a right-hand door. If they are on your left, it is left-hand. Manufacturers print this on the box in one line that is easy to skim past.

Where levers earn their place

A lever opens with a forearm or a closed fist. A knob wants grip and a wrist rotation, which is the movement arthritis takes away first. That is why accessibility guidance in commercial building has pushed levers for decades and why round knobs have largely disappeared from new commercial work. Residential requirements vary by jurisdiction and by whether the work counts as new construction or a replacement, so check with your local code office rather than assuming the commercial rule applies to a house.

The same ease of operation is a drawback in two situations. A lever can be pushed down by a large dog, which is a regular complaint on interior doors, and it catches on bag straps and coat pockets in a narrow hallway. A lever also needs more swing clearance than a knob, so a door that sits tight against a return wall may not have room for one.

Which combination an exterior door actually wants

Four situations cover nearly every house.

A door with a deadbolt bore and a knob bore, both in use. This is the common case and the easy one. Replace the deadbolt with a smart deadbolt, leave the knob alone, and the job is one screwdriver and half an hour at the outside. The keyed knob below carries on doing exactly what it did.

A door with both bores where you want one continuous piece of hardware. A handleset covers both in matching trim, at a higher price and with the handing question attached. Worth it if the door is the front of the house and you care how it reads from the street, unnecessary on a side door nobody looks at.

A door with only a knob bore. Here a keypad lever or keypad knob is the only bolt-on answer, and you are accepting latch-only security in exchange for not cutting the door. The options for a door with no deadbolt go through that trade in more detail, including the point at which drilling the second bore becomes the better call.

An interior or connecting door. Garage to kitchen, basement, home office, shared laundry. A keypad lever fits well here and the security argument mostly falls away, since anyone standing in the garage already has other ways in.

What the three shapes cost

Prices move with finish and retailer, they differ between markets, and they change over time, so treat what follows as the shape of the range rather than a quote. A smart deadbolt is the cheapest way into the category, typically somewhere between roughly 80 and 300 dollars depending on whether it carries Wi-Fi, a fingerprint reader or neither. Keypad levers overlap that range and often sit a little lower for the same brand, because there is less bolt and less motor to build. Smart handlesets start around where good deadbolts finish and climb well past them.

The gap between a handleset and a deadbolt is mostly casting, finish and appearance rather than security. The deadbolt inside a handleset is frequently the same bolt assembly the same manufacturer sells on its own for a fraction of the price, which is a reasonable thing to check on the spec sheet if the budget is tight and the door is at the side of the house.

Common questions

Can I just put a smart lock on the handle instead of the deadbolt?

You can, and on an interior door it makes sense. On a front door it swaps a one inch solid bolt for a half inch sprung latch, which is a real reduction in what the door resists. If the deadbolt bore is already there, use it.

Do I need both a deadbolt and a locking handle?

On an exterior door, a deadbolt above a plain latch is the standard arrangement and the handle does not need to lock at all. Two locking mechanisms means two things to operate on the way out, which is how people end up leaving the deadbolt unthrown for months. One lock that always gets used beats two that sometimes do.

How do I tell if my door is left or right handed?

Stand outside, on the key side. Hinges on the right means a right-hand door, hinges on the left means left-hand. Deadbolts do not care either way. Levers are usually reversible on the door. Handlesets are the ones to check against the box before opening it.

Can I replace only the deadbolt half of an old handleset?

Sometimes, and it is worth asking before replacing the whole assembly. Several manufacturers sell the deadbolt portion as a separate part in matching finishes, which lets you fit a keypad or connected deadbolt without touching the grip below it.

The catch is that finishes drift between production runs. A new brushed nickel bolt beside a ten year old brushed nickel grip may not match as well as the catalog photograph suggests, and living finishes such as oil-rubbed bronze will have aged on the door in a way the new part has not.

The short version

A deadbolt is the security, a latch is what holds the door shut, and a handleset is both under one plate with a handing question attached. Measure the backset, the bore diameters and the door thickness before shortlisting anything, and if the door is prepped for both locks, measure the distance between the two bores as well. On a front door, a smart deadbolt above the existing knob is the cheapest and most predictable route. A keypad lever on its own is a step down in security that only makes sense where no deadbolt bore exists and cutting one is off the table. If you are buying a handleset, check the hand before the box is opened.