Of course players will take over property. They'll probably want to improve it too. I'm quite experienced with this by now. Happened in every campaign I have been the DM in. In my case it takes surprisingly little effort to manage.
The building, town
You probably have a map already. Hand over a copy to the players. Done. They probably want to rename it.
Fixing, expanding, improving
You can mostly just wing it. Buildings cost in the thousands of gp and takes months to fix. And good quality is a lot more expensive than a quick-fix. And getting stuff done quickly also costs extra.
But if major expansions are considered, or you deal with an entire castle, then "Fortresses, temples & strongholds" is convenient to read. Seems 5E compatible to me.
Let the players mark all changes on their own map, and ask for an update afterwards.
Traps & weapons
The players will likely want to protect their property with traps. And it wouldn't be the first time a ballista gets mounted on top of a farmhouse in D&D. As a DM you only need to check the costs and delivery times of that.
Costs of everything
The construction workers and craftsmen will want to get paid (partly) up front. Players will demand payment after completion. Do some haggling, and then tell the players that you as a DM cannot be bothered to keep track: So while you guys roleplay that some payment is done on completion, the full cost gets deducted from the character sheets immediately - to avoid bookkeeping. Again, no burden on the DM.
Inventory
Managing the inventory (i.e. furniture, chests with stuff, decorations) should be done by the players. It's a nightmare for any DM to keep track.
Personnel
In the game, personnel (i.e. the butler, the guards) can be treated as inventory. Top tip: Don't do that in real life, it's quite unethical.
Plot hooks
If you make anything - even a penny - disappear from their house, catching the thieves and retrieving their stuff is now priority #1. You can use that as a plot hook or side-quest, but players will see it as the new main quest.