You can deduct only a part of the repairs allocated based on square footage used for office over overall square footage. You cannot deduct the expense for the entire house
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Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases.
Whether the replacement will be considered repair or improvement will depend on whether the replacement adds to the value of your home, prolong its useful life, or adapt it to new uses(in which case it is improvements) or the replacement is to fix failed septic system in order to keep it in running condition(in which case it is repairs).
So If the repair or improvement is simply maintaining the status quo, then it will betreated as a deductible expense but if it creates something new, then it will have to be capitalized and depreciated.
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