Geralt has his own home to renovate in The Witcher 3: Blood and Wine, and it requires you to progress through "The Beast of Toussaint" until the Duchess kindly hands you a deed and key to the Corvo Bianco property (the same property where you killed the Bruxa vampire). This begins the "No Place Like Home" side quest, where you can spend your Crowns to renovate the property. Below, you'll find every upgrade, what it does, and how much it costs so you can see whether it's worth your coin or not!
No Place Like Home Walkthrough (The Witcher 3)
When you arrive at Corvo Bianco, you will meet your Majordomo, who will show off your new home. After the long tour, you can speak with the Majordomo to ask about renovating, where you are provided with these options:
Let's do some work on the house. Yeah, give her a good sprucing up. (5,000 Crowns)
The grounds – be nice to improve those. Need an armor repair table. (1,000 Crowns) Could use a grindstone to sharpen my swords. (1,000 Crowns)
You will need to purchase all three of these upgrades (7,000 Crowns) in order to progress the "No Place Like Home" side quest. Once these upgrades have been purchased, meditate for 72 hours and then your renovations will be complete.
You can return to the Majordomo, who will ask you to search the cellar, and you can use Aard on the loose brick wall to reveal a laboratory. This is where you can transform mutagens from monsters and upgrade them. You can also interact with the workbench on the right to gain an additional charge for bombs and potions!
All Corvo Bianco Upgrades (& What They Do)
After completing the objectives mentioned above, you can return to the Majordomo and purchase further upgrades:
Increases Vitality by +1,000 points for 120 minutes.
Order another weapon rack.
Adds 2 weapon racks to Corvo Bianco.
I need more armor stands.
Adds 2 armor stands to Corvo Bianco.
Let's see to the guest room.
Updates visuals of the upstairs bedroom.
Roach deserves a roomier stable.
Roach's Stamina is increased by 100% for 60 minutes.
Herbs in the garden – that's what I want.
Grows Blue Lotus Flowers, Nazairi Basil, and Winter Cherry.
It will cost you 14,000 Crowns to fully upgrade your Corvo Bianco house, and doing so will allow you to complete the "No Place Like Home" quest. Now, Corvo Bianco is entirely yours, and you can decorate it with paintings, armor stands, and weapon racks, and you can even play Gwent with the Majordomo and choose what deck he uses, but there's no card to be won.
The bed and stables upgrades require you to sleep in your bed to see their effects kick in. You can also read a book from the library to get a 5% bonus to XP in combat for 60 minutes.
Source: Game Rant