how to do depreciation when house changed to second business?

wrote in message news: snipped-for-privacy@i30g2000yqd.googlegroups.com... Suppose you are depreciating your house because you use it partly for business. The basis for depreciation is the smaller of what you paid for or FMV of the building. Say the basis is 100k and you've depreciated 20k. Now you change to a second business, or change the entire home to a rental. What is the basis for the second business depreciation? I'm thinking it is 80k, because the cost basis of the buildings is now sort of 80k, and besides this way it will be impossible to depreciate more than 100k. =======The basis would NOT change. If you had already depreciated 20K, your accumulated depreciation would be 20K. If you had been depreciating 20% of the house, you would now depreciate 100% until the total accumulated depreciation reached 100K.