this process helps to concentrate the urine and increase the volume of water in the blood. Aldosterone acts via a similar method as it acts to increase the production of 3 types of channels: 1) sodium channels.
This means that a new greenhouse costing $20,000 which has a useful life of 25 years would be depreciated at a rate of 8%, twice the straight line rate, of the undepreciated value each year as compared to taking 4% of the original cost each year as the annual depreciation allowance.
If the shed is a permanent building used for a farming business, it would be a useful life of 20 years. The useful life is based on the purpose of the shed, and the permanency. To best determine the useful life, consult Publication 946 or an accountant.