Tonypbwatlanta,
Colorado's constitution does not allow landlocked parcels; easement access rights can be obtained through court for physically landlocked parcels. How does Georgia handle a landlocked parcel under its constitution, statutes, and case law?
If it cannot obtain access, it doesn't have a H&BU independent of this single surrounding property owner. The "market value" definition falls apart.
You have a
monopsony situation.
Now for the hard part:
I'm quoting from my recent report -- but nowhere as severe as your situation (mine was a simpler question of how much the neighbor would pay for the one adjacent city lot of the 5 congruent city lots).
"Plottage value to the neighbor cannot be calculated in a monopsony situation (I'm paraphrased from Gary Taylor MAI teaching AI's 530 Advanced Sales and Cost Course). A monopsony is an "oligopsony limited to one buyer", where an oligopsony is "a market situation in which each of a few buyers exerts a disproportionate influence on the market." (I'm missing my footnote). One buyer has disproportionate bargaining power -- whose plottage premium, if any, will vary greatly based on their highest and best use, financial situation, motivations, and personal goals desires, rather than a fixed calculable market price. This does not negate the possibility that the neighbor may pay only market value for the one lot, because there may be no motivation to pay any premium at all. The one lot then sells for less than contiguous multiple lots.
You could try a larger-parcel before-after approach, but that is predicated upon a market situation.
You may have to do some type of sensitivity before and after value to calculate how much highest and best use (like additional buildable area) that the monopsonist will gain by acquiring the subject parcel. This could derive a residual land value that the monopsonist might pay.
However, if the institution doesn't want to bargain with the landowner or the landowner is unrealistic, the institution could wait. Wait until the owner is weakened or wait until it can obtain a Treasurer's Deed when the taxes are eventually unpaid? Then value could be small.
In one of the biographies of a skyscraper in NY, the last owners on the block held-out for ridiculous plottage value versus the "as is" improved market value. The skyscraper developer assembling the block offered 2 or 3 times the "as is" market value -- but when they couldn't agree on the sale price, the skyscraper developer built around the last parcel.
Too much depends on the business or estate motivations of the landowner and the adjacent parcel, not market value for the bundle of rights. You are left with an "investment value" to the monopsonist.
You may have some type of crippled "value in use" to the subject landowner because they only get a few twigs from the bundle of rights. . . . . maybe it was on youtube (?), some stubborn guy who owned such a mini-lot refused to sell it to the adjacent or surrounding developer. He got a court order that made it clear that the developer could not trespass on the air-rights without penalties. They couldn't swing a crane boom over the stubborn guy's lot. How much cost in crane time did that take-away from that development's value (how's that for an externality adjustment!)? The stubborn guy showed up everyday and sat and watched with a video camera so that the mocking construction crew did not trespass. It was great fun to watch! The journalist did not answer how the stubborn guy got access to his lot without trespass himself.
Let us know how you finally handle this?!
Tim