maison vs master + question about keying a vacation rental.

[dcf1999]

Hello all! I'm new to the forum and am always eager to learn new things. My newest thing is keying locks. But i'm confused by a few things. Please excuse me if I use wrong terminology and what not.

Background... My family has a rental cabin that we wanted keyed a certain way:
a.) One key for family that opens all doors to house and outbuildings
b.) One key for management company that opens house door only and a "management" utility closet
c.) One key for renter that opens only entry doors to cabin

I successfully keyed all the Kwikset locks around the property to work for the above situation I then decided to get the z-wave electronic locks. You can't "re-key" the new Kwiksets to use multiple keys. Then one of the locks melted from a circuit failure. Now most of the locks are having issues. Long story short, I'm getting rid of Kwiksets and going to Schlage.

Questions:
a.) I wanted to set up a master key system so that all the above mentioned people have to carry one key to access their respected areas. I've been reading about Maison keyed entry. This is where i'm confused.. It could be said that the front door is maison keyed for manager, renter, and me (so one lock that accepts 3 different keys). They say not to key a lock that way, but whats the difference between maison keyed vs master keyed? For example, say I want to create a master key system. I hold the grand master key, the manager has the master, and renter has the change key. So take one lock in the system (front door). That lock has a change key (renter key), master key (manager key), and grand master (my key) but that lock also fits the definition of maison keyed in that multiple users can gain entry. Maybe i'm thinking of this all wrong.. it is 4 am right now.

b.) Is the above situation acceptable (having 3 different keys). I could just have the manager carry an extra key for their supply closet.

c.) I've also thought about creating a Great Grand Master key that controls my personal house, a rental property that I own, and the vacation rental. That way I only have to carry one key and access all my properties. (I've forgotten my key for vacation rental one time. It's 5 hours away. My only saving grace was that I had the bite numbers for the key. I had to have a locksmith make me a key using those numbers). That would make 4 keys for the vacation rental (GGM = me, GM = my family, M = manager, C = renter) I'm assuming that it would be horrible for security if I did this though?

d.) Lastly, and please forgive me as I figure out how to word it. If I did key the locks for 3 keys, is there a best practice way of doing in in regards to what key bite numbers to use? Is it better to have a good variation of different size master pins (situation 1 vs 2 below)? Is it better to have more master pins in each stack (situation 2 vs 1 below) or less? It would, in my mind, seem like situation 1 would be easier to pick because there is only one stack that has 2 master pins. The other 4 stacks only have 1 or no master pins.

Situation 1:
Key 1 = 43478
Key 2 = 48636
Key 3 = 43435

Pin sequence:
M: * * * * 2
M: * 5 2 4 1
B: 4 3 4 3 5

Situation 2:
Key 1 = 43478
Key 2 = 48363
Key 3 = 45853

Pin sequence:
M: * 3 2 2 2
M: * 2 2 2 3
B: 4 3 4 3 3

Thanks for all your help.

Dave

[dcf1999]

Ok, so after doing some additional reading on other treads, i came up with the conclusion that I want to keep all the key biting similar across the keys?

For example:
Grand Master Key (My key): 24369
Master Key (Manager): 44369
Change key (renter): 64369

In the above example, there would only be 3 possible keys that will open that door. If I did say:

Grand Master Key: 43478
Master Key: 48636
Change Key: 45853

Then there are multiple keys that would open it (48873, 45458, 48653, etc...) and that is bad..

this would prevent (what I think is called) phantom keys that may open to door?

[Squelchtone]

Ok, so after doing some additional reading on other treads, i came up with the conclusion that I want to keep all the key biting similar across the keys?

For example:
Grand Master Key (My key): 24369
Master Key (Manager): 44369
Change key (renter): 64369

In the above example, there would only be 3 possible keys that will open that door. If I did say:

Grand Master Key: 43478
Master Key: 48636
Change Key: 45853

Then there are multiple keys that would open it (48873, 45458, 48653, etc...) and that is bad..

this would prevent (what I think is called) phantom keys that may open to door?

Hello and welcome,
Glad you are moving from Kwikset to Schlage. Only thing I want to mention with the grand master key is that you want to keep the cuts of it shallower than the master and change key, otherwise it opens up the possibility of filing a shallow change key into a grand master... but you can't unfile a change key if the cuts on the GMK are shallower.

I also don't like to have any cuts at all be common across the system where all keys have the same pin 3 cut depth etc, but others here may have their own opinions and reasons for it. Someone should see and reply to your question in full later today or tomorrow, thank you for your patience as a lot of folks are away for the holidays.

Squelchtone

[dcf1999]

Why don't you like common cuts? Wouldn't having all the keys random cuts open up possibilities of phantom keys?

So I downloaded a program for designing master key systems. I manually entered in my locks and the users for those locks. I'm starting to answer all my own questions I posted above from looking at what the program spits out. Here is what it gives me for keys:

Keys:
A - 67016 - Grand Master (Opens personal residence, vacation rental, and other rental property)
AA - 67018 - Master key 1 (Vacation rental master key for family members. Opens all doors to that property)
AB - 67010 - Master key 2 (My other rental property. This key would be given to tenants)
AA1 - 67038 - Sub Master 1 (Vacation rental key for manager. Opens entry to house and a supply closet)
AA2 - 67238 - Sub Master 2 (Vacation rental key for renters. Opens only the entry to house)

My personal residence would just be keyed to the grand master.

I'm sure i can play with the settings and make it so it doesn't make any common cuts. I haven't got that far yet.

I'm planning on having Z-Wave electronic locks on both the vacation rental and personal residence. It may be a good idea to have a "spare" key hidden somewhere in case the lock doesn't work. Should I create a sub-master key for the personal residence (that would only open the personal residence)?

Maybe I should create a sub-master for my wife that will open the personal residence and vacation rental BUT NOT the other rental property (for my tenants security)?

[GWiens2001]

Are planning on having the keys to the other rental property able to work on this rental? Other than the grand master? If so, why? It would just add master pins and make picking easier, as well as ghost keys.

Everyone has their own preferences, but I try to avoid common cuts between control keys and other keys on SFIC, but avoiding any cuts in common on non-IC seems extreme to me. It also would add master pins. I also like to have some of the master key’s bittings higher and some lower. There are several ways to master key.

Am hoping you are not posting the actual bitting, just examples.

Example bitting for what I see for your five pin lock:

GM Key - 03493 (your key)
MA Key - 43495 (family/manager key - opens this property only)
SM Key - 47055 (maintenance key - entry and closet)
CH Key - 47453 (renter key - entry only)

This would have two bittings on the GM Key that would not be used in any other key, no key given to maintenance or the renter would have more than two pins in common with either the master or grand master, and the keys used most often - maintenance and renter - would have no deep cuts near the key bow, reducing the likelihood of breaking off the key. Also, no lower level key can be filed to work as a higher key. It also limits master pins to no more than one per pin stack.

If you were to share more bittings, you could reduce the number of pin stacks requiring master pins, which would make picking harder. Remember - every pin stack with a master pin doubles the number of keys that will operate the lock.

Keep in mind that I am not a professional locksmith, and they may give some very valid reasons to not use my method. I would likely use fewer pin stacks with master pins.

Gordon

[Robotnik]

Maison keying generally describes a lock that functions with many different keys, such as the entry door to an apartment building operated by each tenant's dwelling unit key. To a technical point, it's a form of master keying, but it heavily degrades building security to the point where it's against code in many jurisdictions.

If you had a 4-plex vacation property, and each unit key also opened an entry gate (along with your master and the mgt. key), the gate cylinder would be a maison keyed lock. What you're describing is something I would view as a three-level master key system.

[demux]

A high (3 or 4 level) master key system would be what I'd implement in this situation, but keep in mind that the higher the level of the system (and the more change keys needed per master), the more chambers in each lock with master pins, which exponentially increases the number of keys that open the lock. For example, in a 2 level system (master key and change key) with 4 change keys per master, you would only need a master pin in one chamber of each lock, so that the master key and the designated change key for that lock operated it. That would mean a total of 2^1 or 2 keys that operate each cylinder. In a 3 level system with similar parameters, you'd need a master pin in a second chamber, which means a total of 2^2 or 4 keys would operate each cylinder. Add another one and it's 2^3 or 8.

So you can achieve your goal of having each person only carry one key, but it comes at a significant cost to the security of the system. If you can implement a lower order system and have a couple people carry two keys instead, that would be better. Generally speaking, you'd want to implement the smallest system (fewest levels of masters and fewest change keys per master) that would meet your current needs and allow for a reasonable amount of future growth.

If you do want to implement a high order master system, I'd suggest you look into locks with 6 pins instead of 5. Adding a pin doesn't change any of the math I mentioned above, but it increases the total keyspace of the system, which means even though you may have 8 keys operate a given cylinder, that's a much smaller percentage of the total number of keys that can possibly exist, reducing the odds that someone else might carry a key that opens your lock. As an added benefit, 6 pin locks are generally targeted more for commercial applications, which means they'll tend to be a higher overall quality than a 5 pin lock you could get from the local big box store. Schlage makes their classic "obverse" series in a 6 pin format (the EZ code for that keyway is SC4, compared to the ubiquitous SC1 which is the 5 pin version you see everywhere), but they also make a line called Everest which is 6 pins by default and of very good quality with tight tolerances, which would lend itself well to master keying. It's a bit more expensive, but you can sometimes find good deals on eBay and it uses the standard Schlage pinning specs, which means if you already have a pin kit it'll work just fine on it.

[dcf1999]

Thank you everyone for your replies. I'm learning a lot from this forum. I'll break this down a little more. There are 3 properties that I'm dealing with

1.) My personal residence
2.) My vacation rental
3.) A full time rental unit I own

Are planning on having the keys to the other rental property able to work on this rental? Other than the grand master? If so, why? It would just add master pins and make picking easier, as well as ghost keys.

The vacation rental and full time rental will not be able to access each other. The full time rental is a yearly lease property while the vacation rental is rented out on a weekly basis.

A high (3 or 4 level) master key system would be what I'd implement in this situation, but keep in mind that the higher the level of the system (and the more change keys needed per master), the more chambers in each lock with master pins, which exponentially increases the number of keys that open the lock. For example, in a 2 level system (master key and change key) with 4 change keys per master, you would only need a master pin in one chamber of each lock, so that the master key and the designated change key for that lock operated it. That would mean a total of 2^1 or 2 keys that operate each cylinder. In a 3 level system with similar parameters, you'd need a master pin in a second chamber, which means a total of 2^2 or 4 keys would operate each cylinder. Add another one and it's 2^3 or 8.

So you can achieve your goal of having each person only carry one key, but it comes at a significant cost to the security of the system. If you can implement a lower order system and have a couple people carry two keys instead, that would be better. Generally speaking, you'd want to implement the smallest system (fewest levels of masters and fewest change keys per master) that would meet your current needs and allow for a reasonable amount of future growth.

If you do want to implement a high order master system, I'd suggest you look into locks with 6 pins instead of 5. Adding a pin doesn't change any of the math I mentioned above, but it increases the total keyspace of the system, which means even though you may have 8 keys operate a given cylinder, that's a much smaller percentage of the total number of keys that can possibly exist, reducing the odds that someone else might carry a key that opens your lock. As an added benefit, 6 pin locks are generally targeted more for commercial applications, which means they'll tend to be a higher overall quality than a 5 pin lock you could get from the local big box store. Schlage makes their classic "obverse" series in a 6 pin format (the EZ code for that keyway is SC4, compared to the ubiquitous SC1 which is the 5 pin version you see everywhere), but they also make a line called Everest which is 6 pins by default and of very good quality with tight tolerances, which would lend itself well to master keying. It's a bit more expensive, but you can sometimes find good deals on eBay and it uses the standard Schlage pinning specs, which means if you already have a pin kit it'll work just fine on it.

I (and maybe my wife) will hold the grand master that will open all our properties. I will have a master key for my personal residence that I will give to my kids (when they get older) that will only give them access to my house and no other properties.

This is where my terminology might be bad... There will be a master key for my full time rental. That will be given to my tenants. No change keys after that. This way the grand master that I hold, will open both the full time rental and my house, but the tenant of the rental will not be able to open my house.

My vacation rental will have a master key that will open all the doors to that property. That will be given to my family. Then it will have a sub-master that will be given to my manager. That opens all the doors plus their supply closet, but not any outbuildings. After that, there will be only 1 change key to be given to the renter. That will only open the entry doors.

so basically only 3 master keys, 1 sub-master and 1 change key in the whole system. According to the program I used, I will have a maximum of one master pin per stack if any. I think only a few locks will have multiple stacks with one master pin. I'm taking away from this conversation that the less master pins the better and the less stacks with master pins the better.

The bite numbers I posted will not be used. That's just what my program generated. I will have it re-generate a new set of key bites.

I don't know if I can do a 6 pin lock. I'm going to have all the locks at my personal riddance and vacation rental be electronic locks eventually. None of those Shlage electronic Z-wave locks have 6 pin cylinders. Eventually, after all those locks are converted to the electronic locks, the keys will just be there as a backup type system.

Maybe I'm making this more complicated and should just isolate each property so they have their own set of keys. I would still make a master key system for the vacation rental as there will always be 3 levels of access (full, partial, and limited). Then again, I'm having fun learning all this too

[dcf1999]

I uploaded the PDF file that the program created with all the key bites, cylinder pinning, etc... Hopefully this is easier than me trying to explain it.

Obviously the key bites and pinning will be changed. The numbers were just randomly generated. I can change the parameters on how it creates all the pinning / bites as well.

https://drive.google.com/open?id=1p068k-WHw7oE6SyB5OypMgQFPC1am_yZ

It just gives you a better idea on the system I want to create.

This program, along with your replies are helping me better understand and appreciate the master keying system. It's easier for me to understand how it works when I have diagram with the pinning and key bites drawn out.

[dcf1999]

OK. so let me know if I'm thinking of this correctly. Lets say my tenant on my yearly rental moves out and I need to re-key the lock.

According to the PDF file I attached of the randomly generated master system, the tenant's key for the house is 30182. My Grand Master key is 30186. I'd want to keep as few master pins in each stack and as few stacks as possible with master pins. I could literally re-key it to 30166, 30386, 30586, 32186, etc... Any of those combinations would only have 1 stack with 1 master pin, wouldn't cross-key with any other lock in the system, and create no phantoms correct?

Sorry for all the questions and I really appreciate everyone's help.

[demux]

the tenant's key for the house is 30182. My Grand Master key is 30186.

I'd suggest you reverse that. You want the master key to have at least one higher cut than any of the change keys in the system. Doing it as you proposed would allow your tenant, if they were clever enough, to file down the 2 cut in the last position of their key into a 6 cut and thereby have your key.

I could literally re-key it to 30166, 30386, 30586, 32186, etc... Any of those combinations would only have 1 stack with 1 master pin, wouldn't cross-key with any other lock in the system, and create no phantoms correct?

What you are describing is more or less a rotating constant master system. These types of systems are generally used in large master systems where you need a large number of change keys per master, but can be used in smaller systems as well. They're just a bit trickier to do right, you have to really watch the bittings to make sure you don't introduce unintended interchanges.