IMO the biggest reason to put the antenna as far from the house as is reasonable is all the RFI from devices inside the house. Almost everything electrical these days will make some noise on HF. It would be a good idea to place the antenna at various distances from the house, then tune around and see how much RFI there is. Make sure all the TVs, computers, LED lights, phone chargers, etc. are turned on when you do the tests. I would also use at least one counterpoise (i.e., radial) wire laying on the ground for the tests.