Buildings are significant permanent structures in the area of a city. Once built, the city immediately benefits from it. Buildings may be sold whenever the owner wishes (but only one building per city may be sold per turn); an amount of gold equal to the building's production point cost is added to the nation's treasury. Most buildings require a maintenance payment every turn, paid from gold taxes. If a civilization is unable to pay the maintenance cost of a building during the update, the building is automatically sold and the proceeds placed in the treasury. When you capture a city from another civilization (or similarly when you lose one), for each building in the city there is a 20% chance that it will be razed by battle; there is also a chance that the winning civilization will gain an advancement from the loser.
Most buildings (and Wonders) multiply production in some way; for instance, a Library increases the research produced by a city by 50%. In all of these cases, the multiplication is based on the raw productivity of the city due to its terrain and due to its specialists.
This table shows the buildings which may be built in a city. For each is given the required advancement, the build cost in production points, the maintenance cost in gold coins, and the building's effect. For some, there is a "variant" effect, activated if the variant field for the building is set in the ruleset file.
| Airport | Radio | 160 | 3 | Air units produced in the city are automatically veteran. Damaged air units spending a full turn in the city are completely restored. Two cities with Airports can airlift one land unit between them per turn; airlifting transports the unit, using all of the unit's remaining movement points (it must have one point left). |
| Aqueduct | Construction | 80 | 2 | Allows a city to grow beyond size 8 (although a Sewer System will be needed to pass size 12). |
| Bank | Banking | 120 | 3 | Requires a Marketplace; a Marketplace and a Bank together double the tax and luxury production of a city. |
| Barracks | None | 40 | 1 | All forms of the Barracks cause newly created land units to be veterans, and damaged land units spending an entire turn in the city are completely restored. The first two forms of Barracks are obsoleted by the advancement that permits the next form. The variant form of Barracks gives these benefits to all units, not just land units. |
| Barracks II | Gunpowder | 40 | 1 | See Barracks. |
| Barracks III | Mobile Warfare | 40 | 1 | See Barracks. |
| Capitalization | The Corporation | * | 0 | Capitalization is not so much as a building, but a concept. When a city is ordered to produce Capitalization, every turn its net production points are convert into taxes and added to the national treasury. Capitalization is never complete, but may be stopped at any time. |
| Cathedral | Monotheism | 120 | 3 | Makes 3 unhappy citizens content. With the Theology advancement, makes one additional unhappy citizen content; with knowledge of Communism, makes one fewer unhappy citizens content. |
| City Walls | Masonry | 80 | 0 | City Walls make it easier to defend a city. They triple the defense strength of units against ground and helicopter units (other than Howitzer). They also prevent the loss of citizen when a defending unit is destroyed. The variant form of City Walls has the same defensive effect against sea units. |
| Coastal Defense | Metallurgy | 80 | 1 | Only allowed in coastal cities. Increases defense strength of units within the city by 200% when attacked by sea units. |
| Colosseum | Construction | 100 | 4 | Represents entertainment facilities of many kinds, making three unhappy citizens content. The Electricity advancement increases this to four. |
| Courthouse | Code of Laws | 80 | 1 | Reduces the corruption in a city by 50%. Halves the distance to the capital for the purpose of calculation the cost to an enemy of instigating a revolt. Under Democracy, also makes one unhappy citizen content. |
| Factory | Industrialization | 200 | 4 | Increases production points generated by a city by 50% (which will contribute substantially to pollution). |
| Granary | Pottery | 60 | 1 | When a city with a Granary adds a population point, the food storage is reduced to half full instead of being emptied. When a city with a Granary loses a population point due to famine, the food storage is refilled to half full. |
| Harbour | Seafaring | 60 | 1 | Only allowed in coastal cities. Causes all Ocean squares to produce one more food. |
| Hydro Plant | Electronics | 240 | 4 | Increases the production points of a Factory or Manufacturing Plant in the city. A Factory and a Hydro Plant together give a 75% production bonus, and all three together give a 150% bonus. Also cuts the amount of industrial pollution generated by the city in half, if the city lacks a Recycling Center. A city can only build a Hydro Plant if it is next to or on a Mountain or River square. A city can only have one of the electrical plants (Hydro Plant, Power Plant, Nuclear Plant). |
| Library | Writing | 80 | 1 | Increases the research production of a city by 50%. |
| Manufacturing Plant | Robotics | 320 | 6 | Requires a Factory; a Factory and a Manufacturing Plant together double the production points generated by a city (which will contribute greatly to pollution). |
| Marketplace | Currency | 80 | 1 | Increases the tax and luxury production of a city by 50%. |
| Mass Transit | Mass Production | 160 | 4 | Eliminates the population pollution of a city. |
| Nuclear Plant | Nuclear Power | 160 | 2 | Identical in effects to Hydro Plant, but without the limitation of being built near a Mountain or River square. |
| Offshore Platform | Miniaturization | 160 | 3 | Only allowed in coastal cities. Adds one production point to all Ocean squares. |
| Palace | Masonry | 100 | 0 | Makes the city your capital city and the center of your government. Corruption in your cities is usually related to their distance from your Palace. Loss of your capital results in Civil War. |
| Police Station | Communism | 60 | 2 | Reduces the unhappiness caused by military units outside the city by two (for Democracy) or one (for Republic). This building has no effect under other governments. |
| Port Facility | Amphibious Warfare | 80 | 3 | Sea units produced in the city are automatically veteran. Damaged sea units spending a full turn in the city are completely restored. |
| Power Plant | Refining | 160 | 4 | Identical in effects to Nuclear Plant, but without the reduction in industrial pollution. |
| Recycling Center | Recycling | 200 | 2 | Reduces the industrial pollution of a city to one-third. |
| Research Lab | Computers | 160 | 3 | Requires a Library and a University; with them, research production of a city is increased by 150%. |
| SAM Battery | Rocketry | 100 | 2 | Doubles the defense of all units inside a city when attacked by non-nuclear air units and helicopters. |
| SDI Defense | Laser | 200 | 4 | Protects a city and its environs (the 5x5 square area centered on a city) from attack by Nuclear missile; such an attack results only in the destruction of the missile. Doubles defense of units in the city against attack by Cruise Missiles. |
| Sewer System | Sanitation | 120 | 2 | Allows a city to grow beyond size 12. |
| Stock Exchange | Economics | 160 | 4 | Requires a Marketplace and a Bank; with them, boosts tax and luxury production of a city by 150%. |
| Super Highways | Automobile | 160 | 3 | Increases trade points of all squares with roads or railroads by 50%. |
| Supermarket | Refrigeration | 120 | 3 | Increases the food production of all irrigated squares by an additional 50%. |
| Temple | Ceremonial Burial | 40 | 1 | Makes one unhappy citizen content. Both Mysticism and the Oracle Wonder double this effect; with both, it makes four citizens content. |
| University | University | 160 | 3 | Requires a Library; with the Library, increases research production by 100%. |