Both properties, which are about 2ft apart, are on the narrow strip of land on Sandbanks and will have views of the beach and Poole Bay on one side and Poole Harbour on the other.
Adrian Dunford, from estate agents Tailor Made which is handling the sale, said: “Although it will be for sale for £4m they will have to pass an informal interview. Mr Faull wants to know his neighbours are people he can get on with.”
Mr Faull said: “We’re not being too prescriptive, really we’re just looking for someone fairly normal who would like to live a relatively relaxed life in Sandbanks.
“It would be nice if they had kids, of any age, and a dog – mainly because I find dog owners are generally fairly unselfish people.
“I guess we’re looking for someone as close to us as possible so we have things in common. A self-made entrepreneur rather than having inherited wealth as we’re likely to have more in common.
“Those things would be preferable but it’s not necessary. For us it’s important that we get neighbours that will become friends over time, do neighbourly things like take in packages from Amazon.