40d:How do I increase the value of a room

Wall and Floor quality

Material

Digging a room within a layer consisting of obsidian or flux will inherently give it a higher value than a room built inside a mundane stone such as granite or gabbro. Additionally, veins or clusters of precious minerals (whether ores or gems) which pass through the room can provide a dramatic boost in value.

Engraving

Room quality can be increased by smoothing and engraving the walls and the floor. Stone can be smoothed by any skilled dwarf without decreasing quality, but always engrave with more skillful Dwarves as unskilled Dwarves will permanently prevent you from putting a nice engraving there.

Construction

Constructing floors in a room using high-value building components (such as aluminum or platinum bars, or perhaps soap made from megabeast fat) can dramatically increase the value of a room if its location is important but valuable stones do not occur in the region. Note that constructed floors cannot be engraved, and constructing a floor on top of an existing engraving will destroy the engraving, resulting in the usual consequences of art defacement.

Furniture

Lever

Trap levers can be linked to a support and up to 10 mechanisms can be placed on both the lever and support to increase the room value if you create the Link Support to Trigger job on the lever 10 times before the first link is completed. If desired the lever can then be triggered and the support rebuilt to add unlimited mechanisms to the lever.

The support will also add the value of the material used to make the support plus the architecture skill of the dwarf that built it.

Weapon Trap

Weapon Traps can be built in the room to allow you to add valuable artifact weapons to the room's value.

Cages

Cages seem to add the value of the animals occupying them to the room value, and you can store unlimited amounts of animals in one cage.

Other items

Coffins not set to burial are not considered rooms and so can be built in other rooms without decreasing that room's value. This takes up space, but you do have to put the coffins somewhere anyways. You might as well get value from them.