The building designer skill is used in the construction of certain buildings; the corresponding labor is architecture. Building designer has no influence on the speed with which such buildings are constructed; its only effect is to influence the quality of designed buildings.
 Using architecture
When building structures that require architecture, it is the architect who carries the building materials to the site and clears it of debris. The architect's time spent on each building can be minimized by placing appropriate stockpiles near the selected location and by designating debris for dumping in advance. The building is then built in two stages: the first performed by the architect, and the second by a mason (if the building built from stone, stone blocks, or glass blocks), a carpenter (if it is built from logs or wood blocks), or a metalsmith (if it is built from metal bars or blocks).
 Building quality
Building designer skill influences the quality of "designed" buildings (those listed below). The total quality of the building is determined by the skill of the architect and the skill of the builder (mason/etc.). The game assigns two values that can be viewed with the building list. When determining the overall value of the building, these two values are simply added together to form an overall value multiplier ranging from 2 to 24.
Buildings that do not involve an architect do not have any quality (aside from "built" furniture -- tables, statues, doors, etc.).
Building quality has only two effects in-game: high-quality buildings can occasionally trigger a happy thought in dwarves who notice them, and higher-quality buildings will boost your fort's overall architectural wealth (as displayed in the "created wealth" section of the status screen). The first effect can also be achieved by liberally installing high-quality furniture, however, and the second effect is minimal unless you make your buildings out of high-value materials (such as platinum or artifact components).
Destroying a masterwork structure (whether via cave-in or building destroyer) will give an unhappy thought to its designer and/or builder (depending on whether the design or construction are masterful), though dismantling it will not.
 Buildings requiring architecture
- Archery targets
- Paved roads
- Screw pumps
- Trade depots
- Water wheels
 Training the building designer skill
The fastest way to train this skill is to designate a large quantity of supports or archery targets for construction in a freshly mined room (that is, still filled with stones) and use burrow restrictions to prevent any Masons from entering the room - the architect will pick up each stone, design the building, and then move on to the next one. Since the buildings never actually get constructed, removing them takes no time, allowing downtime to be minimized. Be certain to enable each trainee's Architecture labor using View (v) > Preferences (p) > Labor (l) > Other Jobs.
Alternatively, build supports out of metal bars and blocks. This will train a dwarf in Metalsmithing too.