@Mark4063 Well it would be taxable in the UK (although rent a room schemes allow £7500(?) of tax free income per year). I very much doubt the IRS are even that generous.
Every state in the US has different occupancy taxes @Mark4063 so your accountant will need to look into it. However, I would assume that if you have 25 guests in a year who each stay 13 days, the income from their stays will be subject to tax.