Anything the club spends money on becomes an asset of the club. The payment for these assets may happen the day they are bought, or may be spread across the life of a loan, or a mortgage.
The club's accounts show the amount written off each year over the expected useful life an asset. So what the club "fixtures and fittings" are written off over 5 to 10 years. So a car costing say £20,000 would be written off over 4 years and would hit the books for £5000 per year. For more substantial assets like the stands or the executive boxes the write-off is done over a longer period of time from 5 up to 50 years depending on how long they think the asset will last.
Because these things are written off of such a long period the figures tend to vary very little on a year by year basis, and there is little that can be done to reduce the costs.
The graph below shows that the costs are generally small, it is believed the rise in 2007 came from the installation of undersoil heating.
It should be expected that the new ground should have caused a big leap in the depreciation. If the view is that the ground will last 50 years then the depreciation should be at around £200,000 a year. This has not been the case, it would be great if anyone had an explanation for this !!
St Mirren - Depreciation