I’m the Zoning Administrator and I’m having a disagreement with our Planning Commission, the following is from our zoning ordinance:
Accessory buildings may be placed on a vacant lot or parcel if it is contiguous to a principal use lot with an existing residential building on the residential lot. The lot or parcel must be owned by and deeded to the same owner(s) as long as the accessory building or use continues.
Where more than one (1) vacant lot is considered a contiguous parcel to a principle use or residential lot with a residential building, only one (1) contiguous parcel shall be used for the construction of an accessory building.
Our issue is in a platted subdivision. A person owns a lot with a residence on it. He also owns three contiguous lots. The Planning Commissioner says they may put an accessory building on any one of or all the contiguous lots as they are all one parcel. I say he may build an accessory building on only one of the lots.
Contiguous means "touching," "in actual contact." So if you have the four lots situated in a row: 1, 2, 3, and 4. Then lots 1 and 2 are contiguous. Lots 3 and 4 are contiguous. But lots 1 and 3 are not, lots 2 and 4 are not. If the principle use is on lot 1, then only lot 2 is contiguous. If the principle use is on lot 4, then only lot 3 is contiguous. Only the contiguous lots are where the accessory could be built. If the principle use is on lot 2, then both lots 1 and 3 are contiguous (and which lot the accessory is built on would be the applicant's choice). If the principle use is on lot 3, then both lots 2 and 4 are contiguous (and which lot the accessory is built on would be the applicant's choice).
As to if the four lots are one parcel or not will depend on how the zoning ordinance defines "parcel."
The part of the zoning ordinance quoted in your question is saying that the two lots must be kept together and sold as a single unit. In other words one cannot build the accessory building to the principle use (house) and later sell the accessory building without also selling the lot where the principle use is located, all to the same person.
So if the principle use (house) is on lot 1, and the accessory is on lot 2 -- then lots one and two must always stay together. But lot 3 or 4 can be sold to someone else. If the principle use (house) is on lot 1, and the accessory is on lot 3 -- the zoning ordinance only requires lots 1 and 3 to be kept together. But lot 2 might be sold to someone else, but that creates two separate parcels with a gap in-between. It appears that is what the authors of this part of the zoning ordinance are trying to avoid.
I chose a simple example of explaining this, four lots all in a row. But it might also be four lots so that they all touch at a corner (contiguous) (in a square arrangement) where lots 1 and 3 might be contiguous, and even if lot 2 or 4 are sold, lots 1 and 3 still touch. If that is the case, obviously that entirely changes the answer and thinking given above.
On a slightly different note: In the first instance the zoning administrator is responsible for interpreting and applying the zoning ordinance. If the zoning administrator wishes to discuss it, or converse, that is an ordinance interpretation case that goes before the zoning board of appeals. It does not get discussed or placed on the planning commission agenda. If the planning commission (not one member, but an action of the majority of the planning commission) does not agree with what the zoning administrator ruled they can appeal the zoning administrator's decision to the zoning board of appeals.