Art is a non-depreciable asset and gains value over the years. How is this value determined? For assets that depreciate there is a depreciation schedule. Is there a similar schedule for non-depreciable assets?

Thanks

No there is not.

You just keep it on your balance sheet at the purchase price (historical cost) and when you sell it, you reap the profits. It is the same with Land.

If you want, you can indicate in your notes the Fair Market Value of the non-depreciable property in your opinion.