Master Keying for a Small Building or Shop: How It Works and Who Holds What

If you own a small building in South Philadelphia, or run a shop along Passyunk Avenue or the Italian Market, you know the key problem. Somebody needs access to the back room, somebody else needs access to the front, and you need access to everything. You end up with a drawer of keys and a headache.

Master keying is the standard answer. It's one of the services we list, along with rekeying, lockouts, and installations, for both commercial and residential customers. Here's how it works, in plain terms, and what you should decide before you ask for one.

The idea in one paragraph

In a normal lock, one key lifts the pins to one exact height, and that's the only key that opens it. In a master keyed lock, the cylinder is built with an extra set of pin positions, so two different keys can each lift the pins to a legal height. One is the key for that door only. The other is the master, which opens that door and every other lock built to accept it.

The key hierarchy

Systems get described as a pyramid. From the bottom up, the levels look like this:

• Change key: opens one lock, or a group of locks keyed alike. A tenant's apartment key is a change key.
• Master key: opens every lock in a group. A building manager's key for all the apartments on a floor is a master.
• Grand master key: opens several groups of locks at once, each with its own master. An owner with two buildings might carry one.
• Control key: found on systems with removable cores. It lets the owner pull a lock core out and swap it quickly without taking the whole lock apart.

A small building rarely needs the whole pyramid. A three-unit building might have a change key for each unit and one master for the owner. A shop might have a key for the front door, a key for the office, and a master for the owner that covers both.

A picture to make it concrete

Picture a rowhome converted into three apartments with a shared front entry. Each tenant gets a key to their own unit and the front door. The owner holds a master that opens all three units and the entry. If a tenant loses a key, the other two tenants are unaffected, and the owner doesn't have to run to three doors to fix one problem.

The trade-offs, said honestly

Master keying is convenient, and it has costs worth knowing about. Because each lock accepts more than one key, a master keyed cylinder is a little more complicated inside than a single-key lock, and it can in principle be opened by more key variations. Good design keeps that in check, but it's a reason to choose a quality cylinder and to build the system with a pro who plans it properly rather than improvising.

The bigger issue is key control. Your master key is the most valuable key in the building. If it's lost or copied without your knowledge, every lock it opens is affected. If a master goes missing, the usual remedy is to rekey the locks it covers, which is a hassle but a fixable one. That's why the hierarchy has to be planned around who really needs what.

Decide these things before you call

• How many locks are in the system, and which doors belong to which group?
• Who needs access to which doors, and who needs access to all of them?
• How many keys of each type will you want cut?
• Where will the master key and your written key record be kept?

You don't need all the answers. Come in with a sketch on the back of an envelope and we'll work out the rest. It helps to keep a simple written record of who holds which key and when it was issued, even if it's one page in a folder.

Existing locks versus new ones

Sometimes the locks you already own can be converted to a master system, and sometimes it's cleaner to install new ones. That depends on the brand and model, which is why it helps to bring a photo or the hardware itself. We service Kwikset, Schlage, Baldwin, Emtek, Master, ILCO, Mul-T-Lock, Arrow, Yale, American, Segal, Marks, AdamsRite, Corbin Russwin, and Abus, so there's a good chance we know what you have.

We offer free estimates in person or over the phone on sales and installations. Satisfaction is guaranteed on all lock installations and repairs, and when you're planning a system for a building, that matters more than the sticker on the box.

Tenants come and go

One more advantage of a keyed hierarchy is turnover. When a tenant moves out, you can rekey just that unit so the old key stops working, and every other tenant and the master are untouched. That's far simpler than changing every lock in the building. The lock work around sensitive evictions is also something we do, and we'll keep the legal side where it belongs, with you and your own advisors.

If you're ready to simplify the key ring, stop by Wilensky's Hardware & Locks at 1113 E Passyunk Ave, Philadelphia, PA 19147, or call (215) 468-4819. We're open Monday to Friday 9 to 6 and Saturday 9 to 5. Our Locksmith Service page lists everything we do, and the Contact page has our form.