What Are The Stellaris Megastructure Requirements?


Ever wonder what the requirements are to build a megastructure? Stellaris megastructures are titanic structures that give an empire specific bonuses. For example, a Dyson Sphere is constructed around a star to tap all its energy for your empire’s use. Unfortunately, any planets in that system turn into frozen wastelands.

You must use a construction ship to build one. Initially you can only have one of each type plus you can only have one per system unless it is a Gateway or Habitat. You must also have any required Perks or Research completed before it can be built. They cannot be built around moons or asteroids.

Detailed Megastructure Requirements

  • Galactic Wonders Ascension Perk must be active for Ring Worlds, Dyson Spheres, and Matter Decompressor. Mega Engineering Technology also must be completely researched before you can build one of these.
  • An Ascension Perk is not needed for Mega Art Installation, Interstellar Assembly, Strategic Coordination Center, Science Nexus, Sentry Array, Habitats, or Gateways. What’s needed is the technology researched by the same name for each megastructure. For example, Habitats require Orbital Habitats Technology to be completely researched.
  • The right DLC needs to be active:
    • Utopia for Dyson Sphere, Habitat, Ring World, Science Nexus, Sentry Array
    • Megacorp for Matter Decompressor, Mega Art Installation, Strategic Coordination Center, Interstellar Assembly
      • Mega Art Installation is unavailable if the empire is a Xenophobe or Fanatic Xenophobe. Also, the final stage of this megastructure won’t be available without the Ancient Relics DLC.
    • No DLC needed for Habitats or Gateways. The Gateway Activation Technology must be completely researched before you can build or reactivate a Gateway.

There are also some things to keep in mind when it comes to requirements. You can only have one megastructure of each type with some exceptions that are discussed later on this page. Generally, you can only build one megastructure per system unless it’s a Gateway or Habitat. Megastructures can’t be built at small planetary bodies like moons or asteroids, and if there are research or mining stations in the system they will generally need to be dismantled first.

For more on how to play Stellaris check out our 101 Beginner’s Tips page.

Where to Build Megastructures

Where to build megastructures depends on what you want to build. Ringworlds and Dyson Spheres need to be built in systems without any habitable planets and there can be no mining or research stations. They must be built in systems with a single star (no black holes). They both render any planetary bodies in the system worthless, either by turning them into frozen wastelands or by pulverizing them.

The exact opposite is true for a Matter Decompressor when it comes to stars, they can only be built around black holes.

A Science Nexus, Sentry Array, Mega Art Installation, Strategic Coordination Center, and Interstellar Assembly must be built at an unhabitable planet. They can’t build at an unsurveyed or habitable planets, at a star of any type, and they can’t be built at an asteroid or moon.

Gateways can’t be built in gravity wells so building one is a little different from the other ones. If you select a construction ship then right click on a planet or star you won’t be able to build one, the tool tip says you can’t build it in a gravity well. Instead, after selecting a construction ship, click on the Build Megastructure icon, choose Gateway, then zoom into the system you want to build it in. The gravity well will be highlighted in red, indicating the Gateway can’t be built in that area. Choose a spot outside the red zone and left click. The Gateway will be built at that spot.

Habitats cannot be built around a star or minor planetary body.

How To Build Megastructures

There are a couple of ways to build megastructures. Probably the easiest way to build one is to select a construction ship, zoom into the system you want to build in, then right-click on the planetary body or star that you want to build at. Select he Build megastructure option that appears on the pop-up, then click on the megastructure you want to build.

Another method, and one that you’ll need to use if building a Gateway, is to select a construction ship, zoom into the system and right-click, then chose build megastructure from the option list that appears. Keep in mind that if building a Gateway you can’t build it in a gravity well, you’ll need to choose a spot outside it, something you can’t do using the method above.

You also need to keep in mind the restrictions for each structure, as outlined previously.

Can Megastructures Be Destroyed?

Short answer is no, except for Habitats. All other megastructures can be captured or ruined but not destroyed unless some type of special event is triggered, like an empire asking you to dismantle one.

Can’t Build Megastructures

These are common reasons why a megastructure can’t be built. Each megastructure has unique requirements, what’s listed below is a general list that applies in most circumstances. A method that usually works is to activate the megastructure build list. The tooltips will usually give you the reason why the megastructure can’t be built.

  • The construction ship you’ve selected cannot travel to the selected system. The path the ship must travel is cut off by a hostile empire, one you’re not at war with but don’t have an open borders treaty with either.
  • They must be constructed at the proper place. Some must be built around a single star while others, like the Matter Decompressor, must be built around a black hole.
  • Except for Gateways and Habitats, they generally can’t be built in a system with another megastructure present.
  • Check to see if there are other stations, like mining or research stations, present in the system. Most megastructures can’t be built if those are present.
  • Most megastructures can’t be built at moons, asteroids or systems with anomalies.
  • Some megastructures can’t be built if habitable worlds are in the system.
  • The DLC that adds the megastructures must be active.
  • The proper research must be completed.
  • Some megastructures require the Galactic Wonders Ascension Perk to be active.

How Many Megastructures Can You Build?

The base limit, without any game mods, is one of each megastructure except for Gateways, Ringworlds and Habitats. Also, generally, only one can be built per system. If you capture an enemy megastructure and repair or restore it or discover one during exploration, it does not count against your limit. You can even build another megastructure in the same system if you need to.

Without mods, the limit can be increased by one with the Master Builder Ascension Perk, and the limit can be increased again by one with the Architectural Renaissance Ambition Edict.

The Master Builder Ascension Perk allows an empire to increase the limit of each type of megastructure by 1. If the limit is currently one then the limit is increased to two for each megastructure. It also increases build speed of a megastructure by 50%. There must be two other Ascension Perks active first before you can choose the Ascension Perk, and one of those needs to be either the Voidborne or Galactic Wonders Ascension Perk.

The Architectural Renaissance Ambition Edict also increases megastructure build speed by 50% and increases the limit by one of each type again. This Edict lasts 12 years.

Rich Gallien

I've always liked board games like chess and PC games, especially space based strategy games, which lead to the creation of this site. I hope you enjoy it as much as I enjoyed creating it and updating it with new games!

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