Developing a small master key system for home w/ SFIC

[cdub]

Hi guys and gals,

First off, thanks in advance for any help on this. Second, I know what I'm trying to do is probably pretty dumb in the grand scheme of things, but I am doing it strictly as a learning experience, so please understand that I realize how crazy this might be. I've already acquired all the hardware, so I might as well plow forward!

Here's what I'm doing: I'm replacing all the locks in my house with small format interchangeable core (SFIC) locks. (I know, I'm weird, but just bear with me). In a few months, I will be renting out a room, so I will have a room mate if all goes well.

Basically, I am going to wind up with a situation where I need the following levels of access (keys?):

TMK - top master key (my key) - opens everything.

Room mate's key - opens the front door (but not other exterior doors), her bedroom door, and the interior deadbolts (some deadbolts require keys on both sides).

Deadbolt key - this key will stay in the interior side of double-cored deadbolts most of the time, and will not operate any other lock. The idea here is that the key is left in place for safety reasons while the house is regularly occupied, but can be removed for security reasons when gone for extended periods of time.

Neighbor key - Opens everything except the workshop door and room mate's bedroom door.

Here are the different doors (cores) I have to secure:

Front door (7-pin)
All other exterior doors (7-pin)
Room mate's bedroom (6-pin)
Master bedroom & office (keyed alike) (6-pin)
Workshop door (6-pin)
Interior deadbolts (6-pin)

To further complicate things, I've got a mixture of 6-pin and 7-pin cores; their locations are denoted above.

It seems like I need to use a combination of master keying and cross-keying / maison keying. I am obviously new to the world of master keying, so I could really use some help.

And if I've truly gone off the deep end here, let me know and I'll try to simplify this a bit.

Thanks

[Evan]

@cdub:

It sounds like you have gone a bit overboard but I did make an example for you below...

While it is possible to integrate 7-pin and 6-pin SFIC locks in the same keying system it is over complicated for the application at hand and you should either replace all the 7-pin cores with 6-pin cores and proper spacers OR have a separate key for entry…

Why are you looking to restrict your proposed roommate from using any of the exterior doors for coming in when you allow this roommate a key to exit but not lock any other door except for the front door behind them?

What is your local fire code for rental property? Most jurisdictions do not allow for the use of double cylinder deadbolts on egress doors on rental property?

Example system/translation of your requirements into keying system nomenclature:

Keys:

AA- Master Key

1AA – Roommate’s key
2AA – Deadbolt key
3AA – Neighbor key

Doors:

Front door: AA, 1AA, 3AA
All other exterior door cylinders: AA
Deadbolt cylinders (interior side): AA, 1AA, 2AA, 3AA
Roommate’s bedroom: AA, 1AA
Master bedroom & Office: AA, 3AA
Workshop door: AA

Example 6-pin system: (remember SFIC system bittings are written tip-to-bow)
(X = no additional pins required)

AA – 941032

1AA – 945054
2AA – 943436
3AA – 945452

Front door pinning:

MP XX4422
BP 941032

Interior deadbolt pinning:

MP XX2XX2
MP XX2422
BP 941032

Roommate’s bedroom pinning:

MP XX4X22
BP 941032

Master bedroom & office pinning:

MP XX442X
BP 941032

Reply to this thread with any further questions you might have...

~~ Evan

[Tyler J. Thomas]

This is all null and void unless you have the control key to get them out in the first place, or the ability to pick them to the control shear line. So, do you have a control key? What are the bittings? I'll create your pinning charts if you give me the control key cuts, tip to bow, coupled with Evan's recommendations.