Dual key apartments

[peterwn]

I have only just heard of these - two apartments (or condo) with a single entrance, vestibule with separate entrances to two units, generally a larger one and a smaller one, both on the same title. Occupants would need two keys if ordinary locks are used. This suggests the common entrance could be trivially maison keyed so occupants need one key only. Seems however such blocks are masterkeyed for emergency access by the superintendent, Fire Department and for routine checking of fire alarms.

This would imply a masterkey system with groups of three locks with one maison keyed as indicated above. This arrangement would chew up differs but this would not be an issue for modest sized buildings. Are such systems used in practice or are occupants expected to carry two separate keys (together with a key or swipe card for the building entrance).

[Sinifar]

We do it a lot. Normally it is an up and down duplex. Use a couple of close keys like 374 xx which would work out to 37413 say for a "master" and the two tenants have the common key of 374 -- and their units are 374 57 and 374 39. That would work well and they don't need another key for the common doors. It is simple masterkeying... IF you need more, then the master could be 37 xxx and your first x could be say 2 -- which gives you about 65 keys to work with. BY having the "37" as common you reduce the number of phantom keys which could work.... Every common pin after that further reduces the chances of phantom keys working.

Sinifar

[peterwn]

We do it a lot. Normally it is an up and down duplex. Use a couple of close keys like 374 xx which would work out to 37413 say for a "master" and the two tenants have the common key of 374 -- and their units are 374 57 and 374 39. That would work well and they don't need another key for the common doors. It is simple masterkeying... IF you need more, then the master could be 37 xxx and your first x could be say 2 -- which gives you about 65 keys to work with. BY having the "37" as common you reduce the number of phantom keys which could work.... Every common pin after that further reduces the chances of phantom keys working.

Sinifar

Assume 32 apartment 'pairs' and two pins constant and three with a wafer each. The ;'common' doors would have two extra wafers. Therefore while each sub-apartment key will not open any other sub-apartment door, it is inevitable that some sub-apartment keys will operate 'common' doors of one or more other apartment pairs. The system could be laid out to avoid this, but maximum capacity would be significantly less than 32 apartment pairs.

[jimu57]

Is this the same as cross keying? I have a situation with an office that has an entrance and 4 offices that need their keys to operate the entrance door.

jim

[Evan]

Is this the same as cross keying? I have a situation with an office that has an entrance and 4 offices that need their keys to operate the entrance door.

jim

Jim,

What is being discussed above is a particularly complicated example of Maison keying.

It is a form of cross keying where usually every key in the keying system will operate a commonly used cylinder, e.g. the front door on an apartment building is operated by all of the keys to the individual apartment doors.

The situation described by peterwn and sinifar is an example of trying to adapt improperly selected hardware to a new pattern of access after the fact. If the condos/apartments described had been equipped with Master Ring Cylinder locksets the keying described would have been much more easily and securely accomplished.

In your situation Jim, where you have four individual offices in a suite with a common entry door, the easiest way to accomplish that is to use key changes with as many identical bittings as possible, only having to place multiple master pins in only one chamber of the common entry door. The entire master keying system is usually designed around any special keying needs like cross keyed or special purpose cylinders.

Is your system already established or is this new work ?

How many levels of master keys are involved ?

If cross keying is done incorrectly it can create a headache of key interchange especially in existing keying systems, so it can be very difficult or impossible to add such locks to an existing keying system without having to rekey many more than the five cylinders you need to work together in a group for that one office suite.

~~ Evan

[jimu57]

Hi Evan

Thanks for your posting. In fact, all the posts explained a lot to me.

The system is in office building that a friend of mine owns. His business is in it as well as other offices that are leased and 4 studio apartments. There is also a small manufacturing business in the back side of his building which he is part owner of. He does own the entire building.

His office is a new renovation. The contractor had the lever entrance locks with 6 pin Schlage kik cylinders supplied and master keyed from a locksmith in another state. There is not a single locksmith in the county I live it. A very rural small town is where this building is. My buddy needs to add/change entrance levers in other areas of the building. I could not get the pinning info from the locksmith that set up the system. I took apart all cylinders and documented how they were all pinned. The one thing I didnt like was that the locksmith used the first 2 positions to load with #2 master wafers. These chambers get more wear than the ones near the rear. Plus the logic he used for mastering jumped around. There are master pins where they are not needed, opening it up for ghost keys.

There is 3 offices in the manufacturing area that are mastered but to a different system.

In one section there is an aluminum frame door that is off the street. Inside that, there are 2 doors that need to be keyed different and one those is cross keyed for 4 change keys inside the office.

Right now, there is 24 doors , 4 to a cross keyed entrance, 3 in another area with a master key, but part of that area has a door that is mastered to his office master.

I have defined new keys that will do everything that is needed. ! master key for the entire building. 2 areas that are cross keyed.

Personally, I would like to have a unique key for each outer perimeter doors (8 of them with 4 different bittings) and leave his office cross key as it. This would require employees to have 2 keys. 1 for the exterior doors (off of the street) and their office key which would operate a door to the office area that is cross keyed. If I do that, might as well do away with cross keying. It will work with his building layout. In fact, one section that has lease offices and apartments have a common entrance into the part of the building. Either cross key OR everyone will have a entrance door key. A single master key would access every door in the building.

Since cross keying is partly to eliminate a person having to carry 2 keys, I understand its purpose. But I see so many problems in my situation. With no cross keying, there would be a office/apartment given to the tenant/employee, and a door key for the are they have access to. Not trying to get out of a complicated system. Just trying to think of what is most secure and not burden people with having 2 keys.

Somebody shoot me down.
jim