This article is for the PC version of Stellaris only.
Construction is the general term for the act of building structures away from a planet' surface, other than spaceports. Constructions are built by ships specialized for this kind of task. Each construction has prerequisites that have to be met before it can be build.
Constructions are primarily built using minerals and impose a steady drain on an empire's income of energy credits. Over-extension of constructions beyond the empire's ability to pay for them is tempting, since station-constructing is a major source of an empire's power and minerals, but it can also spiral it into potentially game-ruining debt.
Construction ships are civilian vessels specializing in constructions and the sole means of an empire to construct stellar emplacements in space. Though they seem small next to a battleship or cruiser, in absolute human terms, these are huge ships that have a small living quarters and a huge cargo bay that holds materials and an army of robotic workers.
Every empire (not pre-sentients and primitives) starts the game able to build construction ships. No additional research is required. Construction ships are defenseless against aggressors and will seek to escape confrontations from hostile forces by default. They can be fitted with better engines and defenses, but lack any offensive capabilities. With the exception of Frontier Outposts and Wormhole Stations, construction can only be done within the borders of your empire.
Outposts and Orbital Stations
The most common job for construction ships is to build mining stations around planets that generate the two major resources in the games' economy: energy credits and minerals. These stations will be the earliest priorities in the game for construction. Some anomalies, when successfully investigated, reveal resources at a celestial object that previously lacked them. Each mining station costs 90 minerals to construct. In addition, they require 1 energy credit per month to maintain unless built on top of an energy source. Both these numbers can be increased or decreased by various other factors like certain technologies that increase all round production.
Mining stations built around planets or asteroids that are discovered to have reserves of special strategic resources will automatically harvest those resources once they have been discovered. Mining stations that are built around habitable planets will cease operation if the planet is ever colonized, their purpose being usurped by the population below. Mining stations aren't entirely defenseless. They have a hull robust enough to prevent easy immediate destruction from small fleets of warships, allowing a rescue mission to be sent. They also have a basic set of weapons at their disposal to fend off smaller detachments of attackers, but they are easily destroyed by large fleets of capital ships.
Research stations can be built around planets, stars and asteroids that generate the materials necessary for the advancement of science and technology. Planets can produce the research materials for each of the fields of science - physics, society and engineering. Some anomalies, when successfully investigated, reveal scientific potential at a celestial object that previously lacked it. Each research station costs 1 energy credit per month to maintain and 90 minerals to construct. Both these numbers are subject to bonuses and penalties.
Research stations built around planets or asteroids that are discovered to have reserves of special strategic resources will automatically harvest those resources once they have been discovered. Research stations that are built around habitable planets will cease operation if the planet is ever colonized, their purpose being usurped by the population below. Just as mining stations, research stations can defend themselves against smaller attacks but will be quickly defeated against stronger ones.
Frontier outposts are built around stars to extend the empire's borders. They can be built around any star not already claimed by another empire. These outposts are especially useful for rich fringe systems that cannot be colonized or which the empire has not colonized yet. They are seen as an aggressive action by neighboring empires. They cost 200 minerals and (30 base + distance) influence, subject to bonuses and penalties. They also cost 1 influence and 3 energy credits per month to maintain. A frontier outpost will also gather any resources on the star it orbits; there is no need to build outposts on nearby stars and construct mining stations or research stations to harvest the desired resources in return. Frontier outpost can prove very valuable, allowing for expansion without colonizing and claiming parts of space where the incredibly valuable strategic resources can be found.
Wormhole stations are a special kind of space station available to players who chose for the wormhole travel option while creating an empire. A wormhole station costs 75 minerals and has a monthly upkeep of just 0.25 energy. They allow for fleets with wormhole modulators to travel between star systems. Having large amounts of wormhole stations is vital for an wormhole empire's infrastructure.
- Main article: Military station
There are three levels of defense platform that can be built in the empire's star systems: the defense platform, defense station and fortress. The larger ones able to exert more power and destructive energies than the smaller ones, but come with an even larger construction cost and upkeep. As implied, defense platforms are intended to defend important planets and systems against invaders. They are mostly immobile, but have a wide range of weaponry that makes a well-placed defense platform a sensible and cost-effective security measure for those locations that are far from a major fleet or crucial in the functioning of an empire.
- Main article: Megastructures
Megastructures are enormous building projects that require large amounts of resources, but also provide enormous benefits. The construction options for the various megastructures are unlocked by selecting the relevant ascension perks.