There are many challenges that come with this feature, but I think they can be overcome... and this is how I would intend to do it.
The first challenge, is the limited number of houses on the map. Obviously you want to combat the situation of too many houses becoming "Claimed" and blocking loot spawn access to other players.
My solution: Only clans can claim in-world houses. A clan must contain perhaps 3 or more players before they have the option to claim a house. Also, only one house can be claimed per clan. The idea is obviously to make it harder to claim a house, increase the utilization of claimed houses... and in this way encourage players to team up and work together.
The second problem is loot spawning: For balance reasons, loot would no longer spawn in a house while it is "claimed"
3rd challenge: Raiding
Raiding houses would be similar to bases. Every house door would be locked to non-clan members and require breaking through by base raiders. Perhaps "lock Kits" could be added to further secure storage... and require raiders to utilize "Lock-pick kits" to open
4th challenge: Building and storage
Obviously you're going to want to use the house... Dressers, fridges, closets would act like storage crates. In addition, small other items could be built and placed... such as crates, gnomes, power generators, etc
The front and back yard could also allow item placement for things such as tents, camping tables, etc
5th Challenge: Fortification
Because doors can only do so much, there has to be some of upgrading and building of defense. So within the house property, create special building parts for Home fortification. Outside, these things would include things such as gates, walls, and upgrades such as metal, barbed wire, etc... Inside, upgrades would be window bars, shutters.... metal doors, etc.
6th challenge: Vehicle storage.
Claimed houses (with garages) would be able to store vehicles (Number depends on size, 1,2-car garage?) Anything blocking the garage (like junk cars) of a claimed house would despawn so you have room to park and players could manually open the garage door just like base gates.
7th Challenge: Going further with upgrades: The Bomb Shelter
I propose a new ultra-rare crafting guide: The Bomb Shelter
The bomb shelter would add a special, underground bunker beneath the house. House models would need to be updated to provide a downstairs accessway once the upgrade is performed. Maybe all houses have a door to the shelter, and the upgrade guide opens up access. Or perhaps hidden stairs is placed in the back yard. This would add an extra internal layer to your fortified house, increasing security and raid difficulty.
Other Upgrades could include things such as powering your house with a generator.... to get things like lights, fridges and stovetop working. This would be very cool once features like cooking, and food spoiling are added and expanded upon.
8th Challenge: Cleaning house
Because most houses in miscreated are pretty nasty... maybe as part of the upgrade process could be a "cleanup process" Either manually, or perhaps automatically... the longer a player claims a house... the nicer and cleaner it gets.
9th Challenge: Decay
Lets say.... 2 weeks of inactivity unlocks a house and makes it claimable, along with all contents?
10 challenge: Family Dog
For goodness sakes, let us find a pet dog who we can "tame" and "claim", and leave in our house to bark at nosy players and help defend our caste!
That's all basically it.... a scattershot of ideas and thoughts into how houses could work if players were allowed to control them. I've got to think that by the time the game is done, there will be enough houses that with the proper restrictions and difficulty associated with doing so.... we could enable house claiming, which is a heavily requested feature in the community.