land can be treated as part of home sale under certain conditions. you do not meet the occupancy requirement so no home sale exclusion is available. because you probably did not elect with the 2020,2021 and 2022 returns to capitalize the interest and taxes thus those cost do not add to your tax basis. you can make the election for 2023 IRC 266. Turbotax does not have the election which must be included with each annual 1040 return. Therefore, you will have to male in the 2023 return unless you want to forego the benefit.
your cost basis is what you paid + costs of improvements + closing costs on purchase. sales expense would include closing costs on sale.
here's what the IRS says about other costs
Constructing assets. If you build property or have assets built for you, your expenses for this construction are part of your basis. Some of these expenses include the following costs.
Land.
Labor and materials.
Architect's fees.
Building permit charges.
Payments to contractors.
Payments for rental equipment.
Inspection fees.
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A literal interpretation would suggest if actual building of the home never started, these costs would not add to basis
