Covers long-term housing, architecture, and building constructions. For traveling accommodations and equipment, check Expedition Gear.

In some ultra-tech societies, construction remains much as it has been since TL6, with the only changes being electronics and appliances. Other possibilities are more exotic, including buildings composed entirely of nanomachines or force fields.

Houses, apartments, hotel rooms, and passenger ship cabins may include a voice-activated computer system that controls climate, domestic appliances, security, and communications. The system is programmed to respond to the occupants’ voiceprints. Cheaper apartments tie into the landlord’s main building computer, which provides similar services, but with less security. Very cheap tenements can be prone to malfunctions…

Media wallpaper permits the illusion of vast space to be created. Most ceilings, and usually at least one wall, may be used as a giant-sized computer or video screen.

An entire town or city may be enclosed by a transparent dome. A low-tech version for a terrestrial habitat could be wire-reinforced shatterproof glass, mist-plated with aluminum to cut sun glare while still letting in light. From the outside it would appear like a giant mirror; from the inside it would be almost invisible. A dome about two miles wide and a mile high would weigh about 4,000 tons. With TL11^ superscience, force field domes are also possible – see Under the Screen (p. 72).

Large, manufactured habitats are usually built using titanium, aluminum, and steel mined from moons or processed from asteroids. Gravity can be simulated by rotation, and power drawn from solar collectors or reactors. A thick shell of slag left over from mining and ore-processing operations can provide radiation shielding.

These are the largest and most expensive space habitats. They are giant cylinders (or paired cylinders) a few miles wide and several miles long, rotating to simulate Earth-normal gravity. Inside is a complete environment with park and urban landscapes. An O’Neill cylinder can house a few million people. Large populations may be supported by additional agricultural habitats.

Smaller than the O’Neill cylinder, but still very large. A typical torus is shaped like a bicycle wheel, with gravity and landscaping on the floor of the outer rim. The spokes are elevators that lead to a central microgravity hub. A typical model houses 10,000 to 100,000 people. Radiation shielding is a major expense.

This is a sphere of any size, with smaller cylinders attached around it. The central sphere rotates; the cylinders do not. The sphere is simple to build, but the rotation only simulates gravity in a strip around its equator. This can be inconvenient without superscience artificial gravity.

Instead of using an asteroid as raw material, it can be completely or partially hollowed out, with people living in tunnels inside. A large asteroid such as Ceres could support billions of inhabitants.

These genetically-engineered trees (or living machines resembling trees) are adapted to space conditions and planted on comets. They grow to enormous size in microgravity. Their leaves serve as solar collectors, and their bodies house cities.

If microgravity is tolerated or TL10^ contragrav generators (p. 223) are used, space habitats could be thousands of miles across without exceeding material strength limits. A large asteroid or moon might be dismantled into dozens or hundreds of continent-sized habitats.

If manufactured using carbon nanocomposites and diamondoid, the largest enclosed space station that is structurally sound while rotating to simulate Earthlike gravity would be a cylinder 550 miles in diameter and 2,750 miles long. It could comfortably house 75 billion people.

At TL 10, an intelligent house (above) can have a sapient brain that handles everything from doing the dishes to tutoring the children. It is smart enough to anticipate the owner’s desires, which may be good or bad. When someone says a house or apartment has personality, they may mean exactly that.

Within the house, domestic products can be made of smart, self-repairing materials. Living carpets may clean themselves. Beds, tables, and chairs may assume different shapes, textures, and colors to fit the occasion, or be absorbed into the walls and floor when not in use. Artifacts and interior partitions may change color with a word to the house computer.

These houses give a +2 (quality) bonus to Housekeeping skill. A typical three-bedroom home is $100,000.

Contragravity generators let unmodified humans live nearly anywhere in Earthlike comfort. Floating buildings, or even cities, are possible, usually with multiply-redundant power plants in case of failure. With TL11+ biotechnology, the cities might even be alive! A less extravagant dwelling is the contragrav houseboat, which can be tethered just above the trees – or above the clouds.

Contragravity lets mineral-rich high-G worlds be settled without having to worry about exoskeletons or creating variant humans. Artificial-gravity generators can supply normal gravity to asteroids and small moons, and sprawling orbital cities can be constructed without worrying about providing spin.

Holotech projectors can create illusionary partitions and art images; redecoration is as easy as changing programs. Any room in the home or apartment might seem to be floating in starry space, or hidden in a tropical jungle. Scented air conditioning and realistic audio effects can complete the illusion.

An entire star can be partially or completely enclosed. Societies might build them in systems lacking habitable planets, or to collect power for major industrial projects like large-scale antimatter construction. (A sun-like star has an output of around 4¥1026 watts). These projects generally require self-replicating machines (p. 92) to build. All of these structures could also enclose larger or smaller bodies – a ring or sphere around a small red dwarf star would be easier to build. Stellar structures are generally so large that the curvature of the horizon would be invisible; standing on the inside of a Dyson sphere would be like standing on a flat surface with a large bowl overhead. Common examples are:

A loose array of light sails and solar energy collectors which beam energy to other habitats. It would require the mass of a large asteroid to be dismantled and used to manufacture solar collectors. This type of Dyson sphere could be built as part of a project to power lightsail-equipped starships.

A shell of energy collection platforms and habitats orbiting independently around a star. The star would be dimmed, but possibly still visible through gaps in the shell, although the whole sphere would shine very brightly on infrared. It requires dismantling a number of planets.

A solid shell around a star, with the inner side sculpted into continents, oceans, etc. with a surface area of over 600 million Earths. It would be a microgravity environment unless artificial gravity generators were used. Building it requires dismantling a solar system and using exotic materials. Multiple, layered spheres are also possible.

This is a solid ring around a star, with the inner side sculpted into continents, oceans, etc., rotating for gravity. A typical ringworld has an area of 20,000 Earths. The rotational stresses involved require superscience building materials. It is also unstable: a space drive or tractor-beam anchoring system is needed to keep the ringworld from drifting into its sun. Variations such as giant disks or tangled tubes are also possible.

Biotech developments may make it economical (though not always fashionable!) to grow living houses with warm fleshy walls, cell-like membranes for doors, and extrudable furniture. A living house thrives on human waste products and other garbage. It may also have security features that let it digest intruders; a classic cinematic plot has such a house being sabotaged so that it devours the occupants. At TL11, a typical three-bedroom home drops to $50,000. LC3.

By generating a low-power barrier screen (p. 191) over a city, planners can dispense with solid domes or underground dwellings – and won’t have to worry about bad weather, either. Or a homesteader can buy a smaller field generator and power plant and set up on the asteroid of his choice. Of course, if the field goes down, he’s in trouble – unless he has a backup generator on. With a powerful force screen and an antigrav generator, a research station could be built deep within a gas giant’s crushing atmosphere, or hovering within a star. The engineering problems would be immense, but think of the view!

At TL12, houses are often filled with utility fog (pp. 70- 71) that replaces some or all solid interiors.

Advanced houses may be made almost entirely of structural force shields (p. 192). They might be filled with utility fog, or use internal force field projections, tractor beams, and gravitic fields for furnishings, overlaid with holoprojections as necessary.

If the forces that created our universe were purely physical, it might be possible to replicate or at least model them artificially, possibly with a high-energy particle accelerator. This is playing God on a grand scale.

If a “new universe” were created, it might occupy its own separate space, usually with some anchor point in our own space that allows its creators to visit or observe it. A telegate (pp. 233-234) could anchor it to a specific point in our own universe. Sometimes a volume of normal space is “pinched off” to become the pocket universe.

The physical laws in such a pocket universe could be similar or different. Time might pass more quickly or slowly there (at least from our perspective). A pocket universe is generally smaller than our own; it might range from microscopic to the size of a galaxy. Most vary in size from a room to a solar system. It is usually stable, although some pocket universes may expand or contract over time. Its size may be a function of its age (if such universes expand) or the amount of energy that was used to create it.

Pocket universes with normal physics might provide the ultimate hiding places from any mundane form of detection, or just extra rooms in a house. The most common example of a pocket universe is an object that is bigger on the inside that it is outside – often a building, vehicle, or container.

Extradimensional sensors, weapons, communicators, or drives that require interaction with the outside are rarely usable from within the pocket dimension unless they themselves work across dimensions (GM’s option). The GM may also rule that certain systems, such as matter transmitters or parachronic conveyers, can operate even if stored extradimensionally. It may be possible to create dimensional “windows” that allow weapons, sensors, communicators, etc. to direct their emissions into real space; these are points of vulnerability, however, and can be targeted by anyone seeking access to the extradimensional room.

A typical pocket universe is a bubble several yards across. The lower half contains a small total-conversion power plant, life support, gravity generators, and the equipment which originally created and now maintains the pocket.

The upper hemisphere can be furnished as the owner desires, perhaps incorporating a suite of rooms, a laboratory, even soil and a garden. Using this technology, what looks like a small shuttle could have the capacity of a dreadnought, or a phone booth could conceal a palace. Entry requires access to a special extradimensional teleporter, such as a telegate (pp. 233-234) fixed to its coordinates.

Pocket universes require specialized, expensive hardware to create. If normal space is “pinched off” into a pocket universe, cost scales with size: find the universe’s Size Modifier (see p. B550), add 10, and multiply by $10 million; minimum cost is $10 million. For example, a sphere 100 yards in radius would be 200 yards across (SM +12) and get +2 SM due to its shape, for a final SM +14. It would cost $240 million to create. The equipment used to pinch off the pocket universe weighs one ton per $10 million cost. Cost and weight include an appropriate total conversion reactor or other exotic power supply. LC2.

When a pocket universe is created, the “other side” will also need a dimensional aperture or anchor (basically a wormhole). This has the same statistics as a normal-range telegate (pp. 233-234), but is 10 times the cost. If damaged or powered down, the contents of the pocket dimension are inaccessible. The destruction of the dimensional interface may result in the components (and anyone in them) being totally lost. The GM may rule that interfaces for sensors and other systems that require windows are 100 times normal cost.