You can extend what your base can do by installing furniture boxes on the building plan. Safes, racks, workbenches, first aid cabinets: all of it is installed through the plan.
How to install furniture
- Buy furniture. Furniture is researched in Larry’s Tree, mostly in the “Furnishings” branch, and bought on the Trade Laptop. Furniture comes as a box: an ordinary item in your bag. It can also be found in loot or taken from someone else’s bag.
- Go to the building plan. The plan hangs on a wall in the house: it is a board with a blueprint. Open it with “Modification”.
- Drag the box into a free place. The places in the plan are split by kind: tables, safes and others. Drag the box from your bag into a matching place.
- The furniture appears at the base. You can use it right after installing it.
A house has only a few furniture places. The bigger the house, the more places it has. Extra buildings give more places: a 
Warehouse holds a lot of storage, a 
Workshop a lot of workbenches. A 
Car Garage can also take extra storage.
What you can install
Storage. Safes and nightstands hold items, racks hold cargo.
Workbenches and production. Each has its own guide: Collecting, Grow Room, Laboratory.
How to protect your base
A base can be hacked and robbed. Here is what to do to make it as hard as possible for a raider.
1. Keep valuables in safes and security cabinets
Not all storage furniture is equally secure. Nightstands and ordinary racks open without a key once the structure is hacked. Safes and security cabinets can’t be opened without a key: a raider will need a 
Master Key.
Nightstands are cheaper and hold just as much, but keep only what you don’t mind losing in them. Money in a bank account can’t be stolen.
2. Put fuses in every structure
Every structure has its own security system: its panel hangs on the wall. 
Electronic Fuses go into its slots, and each one raises the defense level. The higher the defense, the more 
Decoders a raider needs. For example, a Trailer without fuses is hacked with 5 uncommon Decoders, and with every slot holding a legendary fuse it takes 50.
For the base protection and slots of every structure, see the guide Base hacking and defense.
3. Install an Alarm System
An 
Alarm System in a security system slot reports that a hack has started, so you have time to come back. There are three kinds: it alerts only the owner, the owner and the whole clan, or all players at the location.
4. Get a better fence
A fence also has its own security system, and it has to be hacked too. The Farm Fence has no defense, while the Mesh, Metal and Concrete fences are protected and take fuses.
5. Install a First Aid Cabinet
A 
First Aid Cabinet at the base heals you and lets you respawn next to it. If you are killed during a raid, you come back right at the base and can defend it.
6. Repair hacked panels
After a hack, repair the security system panel: fuses aren’t lost in a hack, and the protection is restored.
Why everything needs protecting. An 
Eviction Right is applied to the plot plan and evicts a player, taking away the property on the plot. But for that, a raider has to completely hack every security system at the base. Every well-protected structure makes an eviction more expensive.