This is the classic definition of a solution looking for a problem though.
I don't know about "no need for intermediaries" because of course you need someone who creates and maintains this blockchain, since blockchains are not present in nature (perhaps that is a decentralized group of people but the blockchain and its maintainers are then the intermediary between the two parties) so let's focus on the no physical key part.
If the primary benefit of blockchain is that only the registered owner of the house can get access to it, on that blockchain, that's a pretty weak feature and actually pretty shit. I would like my family to also get access to my house, as well as perhaps other people like houseguests or a maid etc. Keys seem to work pretty well, nobody is pounding down the door to buy "smart locks" as far as I can tell.
I'm not saying blockchain won't provide transformative utility, it might, but it probably won't look like what we imagine it will (existing paradigms, but on a blockchain).
Sorry I meant centralized intermediaries, which is what is often meant when referring to blockchain tech. Some other examples of centralized intermediaries are banks, ticket resellers like ticketmaster, deed notaries, etc.
And as for sharing keys with family members, perhaps just list them as sub-members of the owning member on the blockchain. When the owner changes, all previous sub-members lose access too. This can probably be done using a smart contract
You can certainly do it. But then the problem being solved is "keys are bad". Typically in startup lore you want a product to be 10x better than the existing solution to gain mainstream adoption. I have a hard time picturing smart locks to your doors on the blockchain as being 10x better than keys.
I don't know about "no need for intermediaries" because of course you need someone who creates and maintains this blockchain, since blockchains are not present in nature (perhaps that is a decentralized group of people but the blockchain and its maintainers are then the intermediary between the two parties) so let's focus on the no physical key part.
If the primary benefit of blockchain is that only the registered owner of the house can get access to it, on that blockchain, that's a pretty weak feature and actually pretty shit. I would like my family to also get access to my house, as well as perhaps other people like houseguests or a maid etc. Keys seem to work pretty well, nobody is pounding down the door to buy "smart locks" as far as I can tell.
I'm not saying blockchain won't provide transformative utility, it might, but it probably won't look like what we imagine it will (existing paradigms, but on a blockchain).