What Is a Master Key System?
In a master key system, each lock has two valid keys: an individual "change key" that opens only that lock, and a master key that opens that lock plus others in the system. You can extend this further with grand master keys and sub-master keys for more complex arrangements.
This isn't just for offices and apartment buildings. Master key systems make sense for plenty of residential applications:
Residential Master Key Use Cases
- Large single-family home — front door, back door, side door, garage entry, basement, shed, gates. Family members each carry one key (the master) that opens everything; specific keys exist for shed/garage/gate that don't open the house.
- Multi-generational household — parents have a master that opens the in-law suite + the main house. The in-law suite occupants have a key that only opens their side.
- Vacation rental / Airbnb — you (the owner) have a master that opens everything. Guests get a key that opens only the rental unit, not the owner's closet, storage, or garage.
- Rental homes / duplex / fourplex — each tenant gets a key to only their unit. The property owner / manager has a master that opens every unit (in some jurisdictions) plus common areas.
- House cleaner / dog walker access — a key that opens the front door for a service provider, but doesn't open the office, garage, or upstairs.
- Older parent independence — an aging parent has their own key. Adult children have a master that can open it in emergencies plus their own homes.
How We Design a System
Master key systems require planning. We start by asking who needs to access what, when, and at what level of authorization. Then we design a key bitting structure that gives you the access tiers you need while keeping the system secure (a system with too many keys becomes a security liability).
For best results, we recommend restricted keyways (Medeco, Mul-T-Lock, Schlage Primus) for master key systems so duplicates can't be made at hardware stores. This is essential for vacation rentals and any setup where multiple people will have keys.
Call (253) 796-8550 for a free residential master key system consultation in Auburn.
