|This article is about the current version of DF.|
Constructions are buildings such as floors, walls, and stairs. They can be made of boulders, logs, blocks, and bars of any solid material—including wood, stone, metal, glass, clay, and even soap—and are accessible in the uild-onstruction menu. One exception is the track stop, found in the construction submenu even though it is a regular building.
Unlike most objects accessed from the uild menu, constructions are treated as inert terrain features when completed, with a few limitations as described below. Additionally, constructions can only be interacted with by loo-ing at them or by pressing - to designate their removal. Using the uery or ask selection will give no information after the construction is completed, but will allow removal, suspension, and an idea of the current status before the construction is complete.
In order to make a construction, a dwarf must have the "Wall/Floor Construction" labor enabled, found under the "Other Jobs" heading.
The construction removal labor is required for removing constructions.
No experience is granted when building or removing constructions.
Constructions and mines
Constructions are similar to mined out formations. However, unlike the walls and floors surrounding mined or channeled spaces, constructed features cannot be smoothed, engraved, or carved into minecart tracks. In order to construct smooth stone walls and floors, blocks need to be used in place of raw stone. Wood, metal, and glass constructions are not considered either rough or smooth, but in the case of wood, building with blocks will increase room value - metal bars have the same value as metal blocks and are thus interchangeable (though blocks may be preferred to simplify resource tracking), and glass can only be used in block form.
Order of construction
Constructions, when equidistant to dwarfVerify, are built in a Last-In-First-Out (LIFO) order. That means that whichever constructions are ordered first will be built last. Also, if there is a large group of constructions being built, and a new set of constructions is ordered, the constructions in progress will be ignored until the new constructions are finished.
The sole exception to LIFO is if you place a single multi-tile order (by using the /} keys, to expand the footprint of the construction), as in the case of a long bridge or walkway over a gap or river. Then, that will be built logically, from connected locations out, but it, as a single "order", will be addressed in sequence according to the rules of LIFO.
Respecting the LIFO order is also necessary to efficiently and correctly construct multi-z-level walls.
Constructions which have not yet been completed are technically Buildings, which permits them to be toppled by building destroyers. Once they are completed, they become map tiles, which are effectively indestructible. Constructions are generally inert, resisting building destroyers, but will be destroyed if magma and water can interact in the square of the construction to form obsidian, or in a cave-in. Building and removing a construction can change the floor it is built upon to a default value, removing things like engravings and the "magma flow" floor above semi-molten rock.
Impact on framerate
Constructions introduce slowdowns from two angles:
- It has to keep track of the original item (though there is a DFHack plugin which will delete the item and flag the construction as "recreate the item from scratch when you deconstruct it"), which means that general item lookups take slightly longer (it's done via binary search, so you'd only notice significant slowdowns each time the item count in your fortress doubles).
- It has to keep track of what the construction is made of, using a separate structure that needs to be looked up for each constructed tile that is visible on the screen. These also use binary searches, though with three values (X+Y+Z coordinates) instead of just one so they're a little bit slower. Typically, you only get noticeable slowdowns when you're building something on the scale of FlareChannel.