Le Societe de l'Elephante Blanc
Presents



by Matt Riggsby
(fongg@crsa.bu.edu and wombat@sirius.com)

• Vehicles and Architecture

• Rooms
• Surfaces
• Other Building Components
• Components from Vehicles
• Roofs
• Structure
• Material Descriptions
• Height and Width
• Variant Structural Materials
• Fortified Walls
• Fortification Variations
• Frames
• Excavation
• Exotic Buildings
• Windows and Vision
• Building Time and Labor
• Composite Buildings
• Floors and Pavements
• Bridges
• Land

• Damage to Buildings
• Fire
• Weathering and Natural Disasters
• Repair and Restoration

• Homes
• Churches and Sacred Buildings
• Fortifications
• Public Buildings

Rooms

This section outlines various kinds of plain and special-purpose building spaces. Players familiar with GURPS Vehicles may notice that the volumes given are far larger than corresponding spaces for vehicular components. This is because space inside a vehicle, even a large one like an aircraft carrier, is far more limited than in a building. Anyone believing that the numbers below are unrealistically large should take a tape measure to their own home and workplace.

The rooms below are mostly based on a standard ceiling height of ten feet. This is a tolerably accurate figure for modern homes and offices if one takes into account spaces between a ceiling and the next floor up, but it is by no means a universal height. Many large buildings, from castles to skyscrapers, have an average story height of ten to fourteen feet, with lower floors having even higher ceilings. Most people are used to such dimensions, so while an architect might be tempted to save some money and build lower ceilings, anyone working or living in the building will be extremely uncomfortable.

Plain Rooms
These are basic, unfurnished rooms, equipped with finished floors, windows as appropriate, doors, lighting fixtures (torch and candle holders to TL 4, gas lamps or candles at TL 5, electric lights of various kinds at TL 6+), electrical power outlets (starting late TL 5), and phone, cable, or other informational outlets as appropriate to the TL (a very late TL 5 house might have a single phone hookup, while a TL 8 home could have multi-purpose data line drops in every room). Given appropriate furniture, they may be used as bedrooms, offices, living rooms, libraries, dining rooms, or for any other use that does not require special fixtures. The rooms below are based on a cost of approximately $4 per square foot of floor space, and the GM may use that as a basic figure for calculating the cost of corridors or rooms of other sizes.

Type	Cost	Vol.	Comments
Closet	$25	60	Built-in closets are uncommon before TL 5
Small Room	$200	490	About 7 feet square. Appropriate for a servant's bedroom, small office, or small storage room.
Medium Room	$700	1700	About 13 feet square. Average bedroom, den or smalldining room, mid-size office.
Large Room	$1400	4000	About 20 feet square. Large living room, bed room, or office, small private library or conference room.
Public Room	$2800	8000	Just under 30 feet square. Two-car garage, reception area for a small office building, seating in a small restaurant.

See example.

Kitchens
Cabinets or storage jars/baskets, a hearth, fireplace, or stove, a sink (given sufficient size and attachment to a plumbing system), and permanent equipment such as cutting or grinding boards. At TL 5, most kitchens include an icebox. At TL 6, most kitchens include an electric refrigerator. At TL 7, given sufficient size, most kitchens add an automatic dishwasher and a microwave oven. Very high-tech societies (TL 10+) may have automatic food synthesis equipment. For kitchens of other sizes, the GM may wish to calculate a cost of $12 to $15 per square foot of floor space.

Type	Cost	Vol.	Comments
Tiny	$150	200	A small heat source and minimal food storage, roughly equivalent to the kitchen of a low-end studio apartment.
Small	$1700	1300	Sufficient cooking and storage area for a family of four or five.
Medium	$3800	2800	A gourmet or large family home kitchen or a kitchen for a very small fast food restaurant.
Large	$7000	5000	Kitchen for a small restaurant or large household, such as a castle.

Bathrooms
Sinks, toilets, tubs, and other hygienic fixtures. In relatively wealthy areas, these may be found inside buildings as early as TL 2, attached to early plumbing systems, although latrines and bathing fixtures tend to be placed in different rooms. High-tech bathrooms may include ultra-sonic vibratory showers, robotic makeup appliances, or automatic hair and nail grooming devices, and seem the logical location for privately owned autodocs. For bathrooms of other sizes, the GM may wish to calculate a cost of $12 to $15 per square foot of floor space.

Type	Cost	Vol.	Comments
Tiny	$150	100	A single fixture, such as a toilet or shower stall.
Small	$300	360	A half-bath (toilet, sink, and shower stall).
Medium	$1100	1000	A full bathroom, including a bathtub, toilet, and sink.
Large	$2200	1600	A lavish bathroom, perhaps including two sinks and a bath large enough for two.

Surgery
A room with cases for instruments and expendables (bandages, silk thread, etc.), washing-up facilities (actually in an adjoining room), copious power outlets (at TL 6+), easily cleaned surfaces, and bright, easily adjustable overhead lights. This is a full operating theater, far better equipped than the "operating rooms" of GURPS Vehicles, which are more akin to the densely packed emergency care facilities of ambulances. The GM may rule that the medical equipment in Vehicles is sufficient only for trauma care and minor surgery (appendectomies, tonsillectomies), and full surgeries are necessary for limb transplants and other major operations. A surgery has enough room for a full surgical team of six to eight people to work around the table. In a pinch, two patients can be placed side-by-side for transplant operations. An operating theater costs at least $100,000 and takes at least 5000 cf.

Laboratory
A small chemical, biological, or physical laboratory with work benches, appropriate equipment, and (at TL 7+) computer facilities. Such a laboratory is sufficient for performing small-scale research appropriate to the TL by a team of up to 8 people working comfortably or up to 16 in very cramped conditions, although some fields of study will require extensive extra equipment. For example, high-energy particle physics will need multi-million dollar, miles-long particle colliders. 5000 cf., $200,000.

Workshop
A small workshop outfitted for a particular type of work (use with Mechanic skill, Electronics, etc.). This is essentially the same as a vehicular workshop (p. V66), except it can be used by a crew of up to five, and like the Surgery, the GM may declare than particularly complex work can only be performed with a stationary workshop. 3000 cf., $22,000.

Auditorium
Rows of seats facing a stage or projection screen. Audience seating takes up 6 to 8 square feet of floor space, or at least 80 cf. per seat (mostly because of high ceilings; a mid-size movie theater could easily take up 160 cf. per seat) and costs $40 per seat. A small stage (fifteen by thirty feet) will cost about $2500 and take up 9000 cf. A highly reflective fabric projection screen costs about $.25 per square foot, although a simple white-painted wall works nearly as well.

Drydock/Vehicle Repair Garage (TL 5)
Like a workshop, but designed for extensive repairs on a vehicle. Such a garage may be found in well-equipped auto repair establishments. Includes diagnostic equipment, a full range of tools, and, where appropriate, hydraulic, magnetic, or antigrav lifts. A drydock substitutes pumping and cradle equipment for a lift. Takes 2.5 times the volume of the largest vehicle to be fixed, costs $20/cf.

Clean Room (TL 6)
Any type of enclosed space at TL 6+ may be made into a "clean room," rooms with exceptionally clean air. Airlocks and a slight overpressure keep outside air from mixing with the air of the clean room, and special filters reduce the number of dust particles in the air. Clean rooms are invaluable in work on computer chips, nanotech devices, and some genetic engineering. Clean rooms cost an additional $7.5/cf. at TL 6, $5/cf. at TL 7, $2/cf. at TL8, $.5/cf. at TL9, and $.25/cf. at TL 10+.

Surfaces

Hydraulic Cement (TL 1)
While common mortars and paints are waterproof enough to withstand most weather conditions, they can't stand up to sustained immersion. However, special ingredients can be added to make a structure completely watertight. At low TLs, mortar is mixed with ingredients like pulverized brick. At higher TLs, rubber compounds and plastic coatings protect against water cheaply and effectively. This kind of mortar, called hydraulic cement, is used to coat surfaces of wells, cisterns, river bridge supports, swimming pools, and other structures meant to hold or resist water. Hydraulic cement costs $.05 per square foot.

Video Wall (TL 7)
The successor to projection screens, a video wall is a giant television-like screen, which can be used to show any video signal the user desires. At TL 7, video walls take the form of giant "Diamond-Vision" and similar TV-like screens, costing around $100 and taking up three cubic feet per square foot of viewing area. At TL8, video walls cost $80 per square foot of area and become a few centimeters thick, taking up effectively no volume. Cost drops by half for every TL above 8. As prices drop, whole rooms can have video wall coverings on walls, floors, and ceilings, creating a whole video environment (although holographic projectors can create an illusion of space more effectively), and buildings can be encased by video walls, allowing them to change their appearance.

Programmable Buildings (TL 11)
One of the primary domestic uses of bioplastic is in variable-geometry architecture. Any room can be made programmable at a cost of $7 per square foot of surface area ($2 if it is already in a polycarbon structure). A programmable room can spawn its own furniture and other fixtures, making regular furniture irrelevant. The occupant could "turn on" a bed at night (making it larger or smaller, depending on how much company he had), changing it into a desk and chair the next morning, calling up a tub if he wanted to take a bath or a sink to brush his teeth. A programmable room can take advantage of information, power, and water/sewage hookups to bring up faucets, phones, stovetops, and other fixtures anywhere in the room the user desires, shrinking them away once they are no longer in use. Combined with video walls, this can give the occupant complete control over both the look and feel of his room. An entire polycarbon structure may be made programmable for an extra $2/sf. Such a building can change to any shape the user wishes as long as it does not grow beyond double or shrink to less than 10% of its original volume or uproot itself from its foundation. In such a building, a floor of office space could shrink to nothing, while the lobby could turn into a bar or and auditorium, or a family garage could disappear when the occupying vehicle is gone, opening the living room up into a tennis court or meeting space for the neighborhood association.

Other Building Components

Stairs
A stairway may be built as a structure with an area equal to its width times the sum of its height and length. Stairs may be made from wood, brick, ashlar, concrete, metal or polycarbon. Brick, stone, and concrete stairs must have at least two levels of reenforcement.
See example.

Heavy Doors
Doors made with heavy-duty materials and strong locks (see the section on Damage to Buildings for more detail on door DR and HT). A door's HT can be increased for $.75 per sf per point of HT. DR increases by 1 per 8 points of increased HT, maximum DR 10+(TL*2).
See example.

Drawbridge
A door hinged at the bottom rather than at the side, the drawbridge is designed to open out over a ditch, forming a bridge when open. A drawbridge also includes a counterweight mechanism allowing easy raising and lowering. The average drawbridge can be raised or lowered in about 10 seconds. At TL 6+, a drawbridge may be driven by a motor at a 20% increase in cost, so it does not require someone to raise and lower it. The lifting mechanisms cost $10 and take up 1 cubic foot per square foot of door area if the lifting mechanism is placed indoors.

Portcullis
A heavy gate which may be dropped into a doorway from above as a last-ditch effort to prevent either escape or invasion. In low-tech buildings, the portcullis is mounted above a doorway (the wall surrounding the doorway must be at least twice as high as the doorway itself) along with winching mechanisms to drag the portcullis back up after it has been dropped. Once dropped, the sharpened points in the bottom dig into the ground, making the gate extremely hard to lift even for someone working the integral winch mechanism (a portcullis can be drawn back up at a rate of 1 foot per second). Anyone standing under the portcullis will surely be severely injured if he cannot dodge out of the way (treat as being fallen on by an object weighing 50 lb./square foot, damage is impaling). The additional mechanisms cost $2 per square foot of gate area and take up space immediately adjacent to the portcullis with a volume in cubic feet equal to half the gate's area in square feet. At TL 5+, the portcullis usually takes the form of a flexible shutter that can be unrolled over a storefront or door (takes effectively no volume) and locked for added security. At TL 6+, it may be motor-driven for a 20% increase in cost. This won't make it drop any faster, but shopkeepers in urban areas, who would otherwise have to lift and lower heavy metal shutters daily, find it a great convenience. A portcullis initially has DR 2, HT 10, but may be strengthened as a regular door.

Secret Doors
Doorways and their latching mechanisms may be hidden by skillful painting or decoration. The architect may designate how the latch is operated (false book in a bookshelf, signal from a remote control, etc.). The purpose for hiding a door may not be for duplicity so much as simply not wanting to break up the design of a room with an extraneous door (see the set of the Kenneth Brannaugh production of Hamlet for some good examples). A doorway may be hidden for $15 per square foot of door area (most doors are about 20 feet square). For silent hinges and latches (people in the room must make a Hearing roll at -2 to hear the door open), double cost.

Heating Systems
The earliest heating arrangements, as old as architecture itself, consisted of a stone or dirt hearth and a hole in the ceiling to let out smoke. Smoky and inefficient, the simple hearth remained remarkably common until well into TL 4, probably because of its relative cheapness. Stone, brick, concrete, and metal buildings may add fireplaces for $75 each (fireplaces are included in TL 5- kitchens). Such a fireplace can heat a room of up to about 1500 cubic feet, consuming four cubic feet of wood (about 100 lb.) a day. Buildings made of flammable materials must add a non-flammable chimney before they can have a fireplace rather than a hearth.

An expensive but more comfortable alternative is to build a hypocaust floor. A hypocaust consists of a tile false floor suspended a few inches over the real floor by small pillars. Air is heated in an external furnace and circulated in the empty space, heating the tiles and thereby the rest of the room. Sophisticated Roman designs vented the hot air through a series of hollow pillars, heating the walls as well. While largely known as a Roman technique, similar systems (running heated air through tubes under a stone or tile platform) are used extensively in peasant homes in China. A hypocaust takes up .5 cf. for every square foot of floor space to be heated plus a furnace taking up 2% of the total volume to be heated. Calculate the cost as though the volume were a brick structure (this is an appropriate place to use the cube root of volume squared times six method rather than calculating actual surface area).

TL 5 sees the invention of iron stoves and increased use of coal. TL 5 heating equipment is far more efficient, consuming half as much wood or tenth as much coal. A small iron stove costs $150 and includes an exhaust pipe, so attachment to an external chimney is not necessary.

TL 6+ buildings are heated by a variety of heating systems, ranging from wall heaters to heat pumps. The chart below shows how much a heater costs and how much room it takes up per cubic foot of space to be heated. Volume includes venting as well as the actual furnace and fans. Heating costs depend on a number of factors, including the building's insulation, basic energy costs, and external temperatures, but at TL 7, heating costs of $1 per month for every 200 to 250 cf. heated are not unreasonable for an average winter in a temperate zone.

TL	Vol.	Cost
6	0.015	$2
7	0.01	$1.5
8	0.0075	$1
9	0.005	$.75
10	0.0025	$.5
11+	0.001	$.25

Cooling Systems (TL 3)
Early cooling systems used strategic placement of walls and courtyards to shade work areas as long as possible and create breezes during the hottest part of the day, controlling temperatures in a few confined outdoor areas. However, during the Middle Ages, a few societies began to experiment with methods of altering indoor temperatures. Breeze-catchers could redirect winds through building interiors, and rooms lined with moistened cloths used evaporation to keep ambient temperatures down. Rulers of the Medieval Muslim empire were able to store ice, carried down from the mountains during the winter, in well-insulated basements until the summer, using that to cool rooms as well. However, cooling techniques remained primitive until TL 6, when freon and other compressor-driven air conditioners were developed and distributed commercially.

The chart below shows how much a cooling unit costs and how much room it takes up per cubic foot of space to be cooled. Operating an electric air conditioner costs 25% to 50% more than heating in a temperate zone.

TL	Vol.	Cost
3-5	0.075	$10
6	0.05	$4
7	0.025	$2
8	0.015	$1.5
9	0.0075	$1
10	0.005	$.75
11+	0.0025	$.25

Waterwheels (TL 2)
This includes all water-driven power sources from ancient water-powered grain mills to modern hydroelectric plants. Initially used to grind grain in China and the Roman empire, water power was used in every industry from cloth-making to arms manufacture by the end of the Middle Ages. In the years before the introduction of steam power, manufacturing mills would have strings of waterwheels that stretched across entire rivers. While steam power briefly eclipsed water power, water again became a vital source of energy with the introduction of hydroelectric dams.

Water wheels from TL 2 to well into TL 5 produce mechanical power which is used directly on site. The GM should feel free to set cost and volume requirements for the additional gear needed (grindstones, trip hammers, etc.), but most devices will cost and take the same volume as the water wheel itself. Most ancient and Medieval mills had a regular power output of 2 or 3 KW, more than enough to grind grain into flour for a small village. The strength of the materials involved limit individual mills at TL 4 or less to an output of 40KW. However, there's nothing to stop a builder from building a string of mills along a river. Rather than building single large wheels, builders usually constructed strings of wheels across or along a waterway. At TL 5, water wheels may produce electrical instead of mechanical power at double cost but no increase to volume. All waterwheels at TL 6+ produce electrical power. The earliest hydroelectric dam, built late in the nineteenth century, produced a mere 12.5 KW, but cheap, reliable hydro power caught on quickly. Less than sixty years later, Hoover dam was built, producing 2080 MW at its peak capacity.

The weights, volumes, and costs are per KW of output. A waterwheel should be rated for a maximum power output, although the GM may reduce its actual power output to reflect fluctuations in water supply. The volumes provided below assume an external waterwheel. The wheel itself is ten times the volume given if it is placed inside the structure at TL4-, or five times at TL 5. At TL 6+, the entire assembly has the volume given. Like other power systems, waterwheel machinery requires access space.

Weights are provided for use with GURPS Vehicles. Waterwheels must be stationary to gain power, but they can find occasional use mounted in a vehicle. For example, boat mills were an important resource during the Middle Ages. Mill boats anchored in mid-stream can rise and fall with the river itself, keeping the wheel at a fixed depth and avoiding the problems that fluctuating water levels cause landlocked mills. If the wheel is set between the hulls of a catamaran or the piers of a bridge, the constriction of flow even increases the mill's efficiency slightly.

TL	Weight	Vol.	Cost
2-4	400	5	$1800
5	200	2.5	$900
6	100	1.25	$350
7+	40	.5	$150

Elevator (TL 6)
The elevator is a late TL 5/early TL 6 invention. Most modern elevators consist of a car riding up and down on fixed tracks, pulled by a set of strong cables. The cable runs up to a powerful motor at the top of the elevator shaft, then back down to a heavy counterweight, counterbalancing the weight of the car and, to some extent, the passengers. While the relatively low-tech counterweight makes the elevator efficient, it wasn't until 1857 that the elevator was made safe as well. If the car slips too quickly, a set of brakes will lock it in place. Even in the earliest modern elevators, the brakes were sufficiently strong and quickly deployed to keep the elevator from slipping more than a foot even if all the cables were cut. Small elevators, serving buildings of 10 stories or less, move relatively slowly, taking from 5 to 10 seconds between floors (longer if they are in poor repair), while express elevators in tall buildings can take as little as 1 second per floor. An elevator costs $.75 per pound of lifting capacity plus $.1 per foot of shaft. Most passenger elevators have a weight limit of 1000 to 2000 pounds. To find an elevator's volume, multiply the elevator's floor area (thirty to fifty square feet in most commercial elevators) by the height of the shaft and add ten percent.

Extremely high-tech elevators may be able to go sideways as well as up and down. Such an elevator would be less efficient, since it could not depend on a cable and counterweight system. Rather, it would have to mount its own motor and move around the building under its own power without the aid of the counterweight. As a result, the architect should consult GURPS Vehicles. An appropriate vehicle would be a small tracked vehicle powered by electrical contact or beamed power.

Escalators/Slidewalks (TL 6)
Similar devices for moving people, the elevator and slidewalk (also called a people mover) take an endless belt and attach it to a motor to move people and goods along. A slidewalk simply attaches a series of interlocking plates to a chain. An escalator is slightly more complex, using a series of wedge-shaped steps which are propped up on rails or the moving chain on the "up" or "down" leg of their trip. Both are two to three feet wide. Most slidewalks move at a Speed of 3, while escalators move at a Speed of 1 or 2. Both cost $8 and take up four cubic feet per foot of length. For escalators, be sure to calculate their cost and volume from the length of the actual lifting surface (square root of length squared plus height squared).

Surveillance Cameras (TL 7)
Video cameras connected to remote monitors for active security or recorders for later review. The average camera covers an effective arc of about thirty degrees and an effective range of 50 feet (farther than that and the image won't have enough detail to be useful). At TL 7, cameras are black and white. At TL 8, they are widely available in color, and at TL 9 they become holographic. Each camera costs $100. Add $25 for a motor (the camera scans an arc or full circle if its mounting permits) or $100 for full remote control (a monitor can move the camera to any angle and zoom in and out).

Smarthouse (TL8)
In TL 8, computer systems become inexpensive enough to integrate them into house design. The basic smarthouse takes care of a wide variety of household tasks. It can act as an answering machine, forwarding calls and taking messages, regulate temperatures on a room by room basis, remotely lock and unlock doors, tell the time and give wake-up calls, start coffee-makers and other food-preparation appliances, run sprinklers when the lawn needs watering, and turn lights off and on at staggered intervals when the residents are away. In larger buildings, a smarthouse system can run elevators and turn lights on and off for entire floors as well. A smarthouse system is a Complexity 1 program for a small building (1000 square feet of floor space, enough for a small house), Complexity 2 for up to 10,000 square feet of floor space, Complexity 3 for up to 100,000 square feet, and so on. The program costs $1000 x Complexity. The smarthouse program does not provide more than rudimentary security. For more than the simplest burglar alarms, use the smarthouse program in conjunction with the Internal Security program (p. CY66).

Force Domes (TL 11)
An important peacetime use of force screen technology is the atmosphere-sealing dome. Load-bearing force fields have hideous power consumption levels and prohibitive costs, but a force dome can at least quickly seal off an area and allow the establishment of a breathable atmosphere, letting the architect build buildings within that space. For purposes of resistance to weapons, treat as a force lock (p. V69), only without the auxiliary door. Force domes are also a reasonably good insulator, so they can be used to establish habitable environments in a variety of settings, from deep space asteroids to the innermost planets of a solar system. While they are called "domes" here, they can be configured in any simple geometric shape the architect desires, even in small sizes as windows and doors. As episodes of Star Trek: The Next Generation have pointed out, they can also be used for fire control, sealing off small areas and letting the fire consume all the available oxygen. Force domes cost $50, take up .003 cf., and consume .1 KW per square foot of surface area of the volume to be enclosed. Multiply cost, volume, and power requirements by the atmosphere differential (minimum 1). For example, a dome in deep space supports 1 atmosphere of pressure from inside. An underwater dome under 15 atmospheres of pressure would have to support fourteen atmospheres (fifteen minus one for the pressure from inside). Halve cost and volume for every TL after 11.

Floor Projectors (TL 13)
A space-saving device related to tractor beams, gravity webs, and artificial gravity. Sensors track the movement of people in a room, a computer interprets those movements, and a number of tiny gravity projectors act on the person, allowing him to treat any surface as a floor. Someone can hurl himself at a wall and find himself lying on it, then get up and walk to the ceiling. Proximity sensors will also "catch" furniture and other objects, turning on localized gravity for anything that comes within an inch or so of the surface. The room's occupant can have a desk on the floor, a bed on the wall, and toss old laundry into a corner of the ceiling. $1 and .0001 cf. per cf. of room volume, consuming .035 KW per cf. of coverage.

Luxury Fittings
Wall-to-wall carpeting, optically refined lines, stained glass windows, crystal chandeliers, and the like. This is the sort of thing that an architect can spend as much or as little on as he wants and has no quantifiable game effect. Luxury fittings will increase the cost of a moderately luxurious home by 25% to 50%, or an extremely elaborate building like a Gothic cathedral by two or three times.

Components From GURPS Vehicles

A great many components from GURPS Vehicles can be used in buildings without modification. For example, a land-based anti-aircraft battery may mount a number of guns constructed with the weaponry rules, DEW systems might be equipped with large radars, or a power generation station may have at its heart a very, very large power plant from p. V82-87. Cost and volume for these components are the same as in Vehicles. Weight is the same as well, but irrelevant.

Components which can be installed in buildings as they are written in GURPS Vehicles include: armaments and mountings (chapters 3 and 9), communications systems, searchlights, all sensors, targeting systems, radar/ladar detectors and radio jammers, computers, winches and cranes, autodocs and other computer-assisted medical equipment, teleport projectors, fuel electrolysis systems, screen generators, environmental systems, artificial gravity, all power systems, and force field generators. It is theoretically possible but practically useless to build some systems, such as stealth systems, into a building. The GM may allow special armor types (laser reflective, chameleon systems, etc.) to be layered over a building, but it is likely to be prohibitively expensive.

Roofs

Many buildings have flat roofs, with a surface area equal to the footprint of the top story. However, for structural or stylistic reasons, an architect may choose a different shape. A roof does not need to be the same material as the rest of the building. In fact, it often is not. For example, stone and brick buildings often have wooden or, at lower TLs, thatched roofs. A building may even have multiple roofs. The Gothic cathedrals of Europe have a stone ceiling formed by the vaulted roof, covered by a second wooden, lead-surfaced peaked roof.

Flat Roofs
The simplest type of roof, but not necessarily the best. Below TL 5, flat roofs must be flexible materials, wood or thatch, but they may be fortified with up to six inches of any material. At those TLs, flat wooden or thatch ceilings wider than thirty feet in their narrowest dimension are rare, since such ceilings achieve that width by long beams which can span that far. If available beams can't span that width, such a ceiling cannot be supported. However, wider ceilings can be supported at intervals by frame "walls" on which the ends of beams may rest. Internal walls outlining individual rooms may also support such broad roofs. At higher TLs, flat roofs may be reinforced concrete, metal, or polycarbon. Wood ceilings still need support at intervals at higher TLs, but other ceilings can be arbitrarily wide.

Peaked Roofs
A peaked roof is shaped like an upside-down V. Such a roof must have a sufficient slope for the beams to lean against each other for some kind of support. The height of the peaked section must be at least a quarter of the distance from the peak to the edge of the roof (this is an angle of about 15 degrees). Many roofs are much steeper. Particularly snowy or rainy climates will have sharply peaked roofs to shed precipitation more efficiently. The area of a peaked roof is (h^2+w^2)l*2, where h is the height of the peaked section, w is the horizontal distance from the edge of the roof to the peak, and l is the length of the roofed section. Below TL 5, a peaked roof with a slope of 45 degrees or less must be made of wood, thatching, or a flexible material although they may be fortified with up to six inches of any other material. Peaked roofs may be made of metal at TL 5+, reinforced concrete at TL6+, and polycarbon at TL8+. Roofs with steeper slopes may be made of any material. Don't forget to add w*h square feet to the surface area of the ends of the building to represent the wall space filling in the V of the peak.

Cones
A conical roof may be made of any material, but it is subject to the same limitations as a peaked roof. The area of the roof is (pi*hr^2)/3, where r is the radius of the cone and h is the height of the cone.

Arched Roofs (TL 2)
An arched roof is shaped like half of a hollow cylinder, an arch projected through a third dimension. An arched roof may be made from any material. The area of an arched roof is pi*rl, where r is equal to the radius of the arch and l is the length of the vaulted space. Truly semicircular arched vaults are not universal, so the GM may arbitrarily adjust the area downward by as much as 25% or upward by 200%.

Domes (TL 3)
Like an arched roof, this roof may be made from any material. The surface area is pi*2r, where r is equal to the radius of the dome. The GM may adjust the area of a dome as he would the area of an arched roof.

Structure

Once the building is mapped out and the surface area calculated, the architect may choose a structural material, which will comprise the bulk of the building. As already mentioned, it might be simpler to use the GURPS Vehicles formula to find the building's surface area, but it is more accurate to calculate the building's actual surface area. For the simplest buildings, the architect may simply calculate the building's perimeter and multiply by its height, then add the surface area of the roof and floor. Various factors may complicate this. A building may have upper stories smaller than the lower ones, or they may be made of composite materials (for example, stone buildings with wooden roofs or tile floors). It is also very difficult to build roofs out of certain materials (see the section on roofs below), so the top of the building may be of an unusual shape. Nevertheless, it should be possible to calculate the surface area of the building with a little simple geometry. Once the surface area is calculated and the material determined, multiply the structure's surface area by the cost of the appropriate material for the appropriate TL, modified as appropriate for alternate materials.

TL	Wood	Packed Earth	Rubble	Ashlar	Brick	Concrete	Flexible	Metal	Polycarbon
0	$.5	$.15	$.75	$.9	-	-	$.1	-	-
1	$.5	$.15	$.7	$.9	$.8	-	$.075	-	-
2	$.4	$.125	$.6	$.8	$.75	$.775	$.05	-	-
3	$.375	$.1	$.5	$.7	$.6	$.65	$.04	-	-
4	$.35	$.075	$.3	$.6	$.5	$.55	$.04	$10	-
5	$.3	$.05	$.3	$.5	$.4	$.45	$.025	$9	-
6	$.7	$.15	$.6	$1	$.9	$.95	$.06	$8	-
7	$3	$.75	$2.5	$5.5	$5	$5.25	$.25	$7.5	-
8	$3	$.75	$2.5	$5.25	$4.75	$5	$.2	$7	$6.5
9	$3	$.75	$2.5	$5	$4.5	$4.75	$.1	$6	$6
10	$3	$.75	$2.5	$5	$4	$4.75	$.1	$5	$5.5
11	$3	$.75	$2.5	$5	$4	$4.75	$.1	$4	$5
12	$3	$.75	$2.5	$5	$4	$4.75	$.1	$3	$4.5
13+	$3	$.75	$2.5	$5	$4	$4.75	$.1	$3	$4

Unusual environments can increase building costs. For building in water, as with river bridges or piers, triple building costs. For building underwater (possible only at TL 6+), add 300% to cost plus an additional 100% for every TL atmospheres of pressure or part thereof. For other exotic environments (zero-gravity, the surface of a partially-terraformed planet), increase costs by at least 200% if the builder's society has not yet perfected building techniques for that environment. For example, the first colonists on Mars or the moon would face such a penalty, but their descendants fifty years later would not.

These costs assume relatively easy access to the desired material. The GM should feel free to adjust costs upwards for materials in short supply. Desert areas and asteroid bases are unlikely to have stands of trees ready to hand, and wood would be an extremely expensive material in such areas. The architects of the Classical Greek temples were very particular about where their marble came from, and it has been estimated that half of the cost of such buildings could have been eaten up simply in getting the stone from its often remote source to the building site.
See example.

Material Descriptions

Wood
Wood is probably the most versatile of natural building materials, stronger and more durable than earth, lighter and easier to work than brick and stone. Buildings may be made entirely of wood, and even buildings made mostly of other materials still often incorporate wooden structural members, particularly as floors and framework for roofing. Nevertheless, wood has its own limitations. First, it is flammable (see the rules on fire on p. V184). Second, it is not always available. Arid regions and areas in environmental distress are often very short of wood. GMs may adjust the cost of wooden buildings up as much as desired to reflect poor wood supplies. At TL 7 and beyond, fiberglass and cheap textured plastics are available for the same price as wooden buildings.

Packed Earth
Rammed earth, sod, sun-baked brick, and other hardened-earth materials which have not been fired. Packed earth is the preferred material for many small buildings at low TLs, particularly in dry areas such as the American Southwest and around the Mediterranean. In fact, a great many homes in both regions were made from dried earth until the 20th century and some earthen building are still being built and occupied. Arguably, the material is not used beyond TL 5, and modern areas where it is in use (remote areas of the American Southwest and the Eastern Mediterranean among others) simply haven't caught up. The great advantage of earthen buildings is that materials for them are cheap and plentiful. They are also largely fireproof, although they may incorporate flammable roofing or structural members. However, earthen materials have two important structural drawbacks. First, they require frequent maintenance in wet environments. In very wet environments, such as swamps and anywhere with regular heavy rains, earthen materials are almost impossible to use. Earthen materials are sometimes painted to protect them from moisture and may need repair or even partial replacement after sustained rain. Second, earth is not a great weight-bearing material. It is difficult to build a multi-storied structure from earthen materials, although earthen materials can be used as facings over a wooden framework.

Brick
Fired brick, cinder blocks. Brick (distinct from mud brick) is made from a mud and straw mixture baked at a high temperature, turning it into a hard ceramic which is far more resistant to the elements. While the basic materials are usually cheap and plentiful, brick is significantly more expensive than earthen materials because its manufacture requires a significant amount of wood and skilled labor. Brick, in the form of flat ceramic roofing tiles or brick arches and vaults, may be used as a roofing material.

Stone (Ashlar and Rubble)
"Rubble" is unshaped stone, piled up with minimal regard for fitting individual stones together. "Ashlar" refers to carefully shaped, squared-off stones placed in even rows by skilled masons. Strong and durable, stone is the preferred material for early public buildings and fortifications. Unfortunately, the very qualities that make it desirable for architectural use also make it extremely expensive and difficult to work with. A cubic yard of good building stone weighs in the neighborhood of two and a half tons, and moving large quantities of it can get very expensive. To minimize costs, ashlar masonry is often used as a protective facing for less durable materials, such as rubble or packed earth. After TL 5, stone is largely replaced by concrete, although particularly elegant buildings may boast stone facades.

Concrete
Concrete was initially a Roman invention, a mixture of rubble and a large quantity of mortar. It was ugly, but it allowed very rapid construction. Builders could construct wooden forms, pour in the concrete mixture, and let it set. The concrete could then be faced with another, less unsightly facade. While formulas have changed considerably (sand replaces rocks in modern concrete), the same basic techniques have been used for concrete construction ever since. In late TL 5 and TL 6, builders developed methods of reinforcing concrete with metal rods. Reinforced concrete now forms the core of most modern roadways and skyscrapers.

Metal
Historically, all-metal buildings have been vanishingly rare. However, all-metal buildings may appear in unusual environments such as undersea and space colonies. At TL4 and 5, this will be cast iron or bronze. At TL6+, steel, aluminum, and inexpensive alloys will be predominant.

Flexible
Cloth, leather, plastic tarps, and other thin, flexible materials on light frameworks of more rigid materials. They are, essentially, tents, although high-tech versions can be used in instantly-erected emergency shelters. Flexible buildings may be as tall as the designer desires, but they may not have more than one story.. Buildings from flexible materials may easily be broken down and put back up elsewhere, so unlike other buildings their weight becomes relevant. A flexible building may be taken down and wrapped up into a package weighing (5/TL) pounds per cf. of volume when set up and taking up 1 cf. per 20+(2*TL) pounds when packed up. They take about 1 hour per 1000 cf. of final volume to set up or take down. While flexible structures may be moved around more or less at will, features of that building should be treated separately at the GM's discretion. For example, just putting a tent around a sink or bathtub won't make the plumbing fixtures any more mobile. Flexible materials are flammable through TL 8, but are effectively fireproof thereafter.

Polycarbon
This is a catch-all category for light, rigid, advanced materials, many of which may actually be inorganic. While more expensive than conventional materials, polycarbon materials can be used to construct a building rapidly. At high TLs, polycarbon-based materials may be full of nano-robots who can change the building's shape. Polycarbons are flammable (albeit just barely) until TL 11.

Height and Width

With the development of modern materials, ceilings can span just about any width. However, low-tech materials may require special construction methods if they are to span broad areas. Wider ceilings must take advantage of various vaulting techniques which allow the architect to piece together smaller parts into a stable structure. See the section on Roofs below.

A building's height is limited by economics as much as by technology. Taller buildings need more labor to move materials and more material for a stronger structure, and as a result become more expensive. For buildings over 10 feet tall, increase the structure cost by 1% for every (TL squared)/10 feet of height, or part thereof, beyond 10 feet (minimum 1% per foot). That is, add 1% to the structure's cost for every foot of height beyond 10 feet for buildings at TLs 0 to 3, 1% for every 1.6 feet at TL 4, 1% for every 2.5 feet at TL 5, 1% for every 3.6 feet at TL 6, and so on. For the mathematically inclined, add (height-10)*.1/TL^2% to the structural cost. Some materials are very poor at bearing weight. Increase the cost modifier by half for concrete (but not reinforced concrete), double it for unmortared rubble, and triple it for packed earth. Reduce it by 20% for reenforced concrete and polycarbon. In other gravity environments, multiply the percentage cost increase by the local gravity.

However, beyond increased labor costs, technology imposes no limits on building height. Major cities of the Roman Empire (TL 2) were filled with apartment buildings as much as 100 feet tall, if not taller. Clearly, taller buildings were possible. The tallest monuments of antiquity and the Middle Ages (the Pyramids, the larger Gothic cathedrals) easily topped 100 yards. However, such buildings were exorbitantly expensive. The early skyscrapers of late TL 5/early TL 6 matched that height, while the tallest buildings of TL 7 reach around 400 yards. Doubtless, as materials improve, techniques become more sophisticated, and population pressures increase, buildings at TL 8 and beyond will grow taller still.

Variant Structural Materials

Thatch
In dry areas, the low-tech building material of choice is mud brick. In wet areas, it is thatch. Thatching is made from reeds, grasses, or long leaves bound or woven together to form larger and more durable bundles or mats. Even if it is not the primary building material, it is used for roofing in all but the coldest climates. It is cheap and easy to find and produce in appropriate climates but it is a poor structural material because it will support no weight. Rather, it must be attached to a wooden framework. Thatch is flammable but, contrary to popular belief, will not go alight at the first touch of flame. Well-maintained thatching is tied tightly enough that oxygen has difficulty reaching the inner portions of the bundle. As a result, while frayed, poorly maintained thatching will burn quickly (like a bundle of paper), good thatching burns as though it were wood. Thatched structures cost 10% less than wooden structures and are somewhat less durable (see the section on damage to buildings below).

Unmortared Rubble
The costs for stone constructions assume that the stones are mortared together. However, for rapid construction, the mortar may be left out. Many old farms are bounded by unmortared rubble walls, constructed by farmers piling field stones out of the way. Unmortared rubble costs 10% less than regular rubble and, like thatching, is somewhat less durable than the related material. Unmortared ashlar constructions are possible (the temples of Classical Greece used no mortar), but cost the same.

Reinforced Concrete (TL 6)
Late in the nineteenth century, architects began to build iron and, later, steel frameworks filled in with concrete. These structures proved enormously strong and flexible, and so the skyscraper was born. Reinforced concrete, for these purposes, is any composite of metal and concrete, the most common material for large buildings for TL 6 and 7. It is rather more durable than plain concrete and is far better for building large buildings. Reinforced concrete costs 15% more than regular concrete at TL 6, 10% more at TL 7 and 8, and 5% more at TL 9+.

Inflatables (TL 8)
At TL 6, emergency equipment makers began to produce inflatable rafts with pressurized gas cylinders attached. All the user needs to do is pull a handle, and the raft inflates itself in seconds. At TL 8, this technology can be applied to "buildings." A compressed gas cylinder pumps gas into strategically placed compartmentalized "ribs", quickly erecting the building. A building made from flexible materials may be made inflatable for a (100/TL)% increase in cost and 20% increase in weight. They can inflate themselves to full volume in about thirty seconds. Triple inflation speed in a vacuum. At TL 10+, the gas cylinders are actually two-way gas pumps, so they can deflate and repackage the building in about two minutes.

Fortified Walls

Buildings are not armored as vehicles are. Since it is relatively easy to build thick walls, DRs could soon reach unrealistically high levels. While fortification adds some DR, its primary benefit is in adding to the building's HT. A layer of fortification costs the same as a building structure and corresponds to an inch-thick layer of material. Not all sides of a building need be fortified, nor must they be fortified equally. A freestanding fortification wall, like a castle's curtain wall, can consist of nothing but fortification. Simply multiply the nominal surface area of the wall (wall perimeter time height) by its thickness in inches. For example, a small fortified outpost, fifty by fifty feet square, twelve feet tall (total surface area (50*4)*12 = 2400 square feet), and four feet thick (48 inches), made from rubble at TL 3 costs $.5*2400*48 = $57,600. Fortifications are subject to cost increases as the result of their height.

A building may have composite fortifications, made out of layers of different materials, nor does the fortification have to be made of the same material as the building it protects. In fact, most fortifications were composed of a very hard, very expensive outer layer with a core of rubble or earth. It would also be possible to build a relatively cheap castle by putting up a wooden building and surrounding it with a stone shell.

Individual rooms, which might be used as safes, prison cells, or strongrooms, may be fortified separately. Simply determine the surface area of the room itself (or at least the area of walls to be fortified) and calculate the cost to fortify that area with the desired material. The fortification's HT is added to that of the already-existing walls.

For all-over heavy-duty walls, the builder can double the building's cost to double the thickness of interior walls, essentially adding a layer of fortification to every room, triple cost to triple wall thickness, and so on. This is called reinforcement. The architect may add layers of reinforcement for reasons other than protection against weapons. For example, thicker walls might reflect added insulation, soundproofing, or structural reinforcement to protect against thieves, earthquakes, or other hazards. Packed earth structures should have at least three or four levels just to protect them from everyday wear and tear. Buildings built in high-pressure environments should add one level of reinforcement for every two atmospheres of pressure difference between inside and outside. Underwater pressure on Earth is equal to about 1 atmosphere for every 33 feet of depth. An architect may add up to twelve layers of reinforcement without penalty to the building's overall size. However, after that point, the GM may require him to refigure the building's volume to reflect the fact that the walls are over a foot thick.

See example.

Fortification Variations

These are techniques used in some ancient and medieval fortifications. It is questionable whether or not the modifications were as effective as they are represented here, and they were never widespread, so the GM should feel free not to allow them in his campaign or allow them only in particular places.

Embossing (TL 2)
One construction technique designed to protect stone walls from siege engines is to install projecting stone bosses deeply anchored into the wall. When a boss is struck, it transmits the force deeper into the wall, reducing damage to the surface. On a 1 in 6, an attack by a siege engine or a low-velocity cannon (TL 3 and 4 cannon, but not higher-tech weapons) strikes a boss and damage is halved. A wall must be faced with at least a half-yard thickness of ashlar, although it need not be stone throughout. Embossing increases cost for the entire wall (not just the facing) by 20%. Embossed walls are also somewhat easier to climb (+2 to Climbing skill).

Cribwork (TL 2)
A scheme occasionally used to reduce collateral damage to stone or stone-faced fortification walls is to introduce thick wooden ties or brick masonry within the structure of the wall, usually in horizontal courses at intervals of around six feet. Walls thus divided are more resistant to collapse. Cribworking does not increase wall HT, but it does increase story HT by 5%. While cribworked walls may have wood in their construction, fire does no additional damage; most of the wood is surrounded by stone and mortar where it is difficult for oxygen to get at it, and most architects are careful to choose woods already charred or somewhat resistant to burning. To be cribworked, a wall must be faced with at least a foot of ashlar. Cribwork increases total cost for the wall by 30%.

Frames

The above types of construction assume more or less solid walls. If the architect wants an open but defined space (as with a bandstand, the ancient Greek tomb of Philip, etc.), he may build a frame around the space for one fifth of the cost of a full structure. A frame building may be made with wood, brick, ashlar, concrete, metal, or polycarbon. Frame buildings do not have walls, only widely spaced pillars, thereby providing little or no cover or protection, and they may not themselves hold room. However, complete roofs can be built over them, and if a frame building is sufficiently large a whole building can be built within it. For half of regular construction cost, the frame can be fully load-bearing. That is, an entire structure may be built within and on top of it. This can have many uses. For example, a reinforced concrete or metal structure built across a river or the space between two hills could have a paved "roof" serving as a bridge, or an office building could have an open plaza or marketplace under it. If a frame is directly attacked, it has one fifth the story HT of a regular structure for regular frames, or half regular HT for a load-bearing frame.
See example.

Excavation

For cellars and underground installations, a builder will need to excavate. Unlike above-ground structures, the cost for excavations is calculated from the volume excavated, not the surface area of the space. The costs below are per cubic foot of excavation. The GM should also determine if the site is composed primarily of earth or of rock. Since dirt and rubble must be drawn up and carried away, excavation costs are increased according to their depth just as the costs of tall buildings are increased according to their height (+1% for every TL^2/10 feet after the first ten). Low-tech excavation relies on picks, shovels, and muscle power. In addition to those tools, low-tech miners would light fires and throw cold water on the heated rock. The rapid temperature changes would make rock faces crack, making them much easier to excavate. TL 5 sees the application of explosives to digging, and TL 6 sees the introduction of steam shovels and other power equipment. Higher TLs will probably see the advent of digging and blasting tools related to energy weapons.

Material	TL	0-1	2-3	4-5	6-7	8-9	10-11	12+
Dirt		$.1	$.05	$.04	$.02	$.01	$.0075	$.0025
Stone		$.6	$.175	$.12	$.075	$.03	$.025	$.015

Digging in dirt or loose stone requires "shoring up," building in structural reinforcement to keep the whole thing from crashing down. This is equivalent to building a structure into the excavated space. Any material except packed earth may be used for shoring up an excavation. Excavations in firm earth can be shored up with a frame structure (see above) and a solid roof. Loose earth or sand, however, require a full structure. Tunneling through solid rock requires no shoring up

Exotic Buildings

Tree Houses
Low-tech builders (and ten-year-old boys and their fathers) can use trees as the basis for a lightweight building, building in platforms for floors and roofs, and perhaps even walls, but relying on the structure of the tree to support the building as a whole. However, the size of such a building is limited to the size of the tree, and the placement of branches will limit where the builder can place rooms. Building into and around a tree can reduce the cost of a wooden or thatch building by 25%.

Fantasy and high-tech settings have more exotic "tree" houses, buildings that grow themselves. A fantasy tree house is "built" by constant magical tending, shaping the tree's growth from the time it is a seedling. The GM may make the appropriate spell either an Enchantment or Plant spell. It requires one hour of tending per day (energy cost 1) to tend the tree. By the time a tree is 10 years old, it is large enough to act as a building. Thereafter, the tree may be treated as a thatched building with a volume of 50 cubic feet per year of growth. The tender may indicate where rooms are and what shapes they have. The branches and leaves grow to form enclosed hollows, equivalent to thatched walls, and grows branches and hollows to form convenient steps and ladders. If the tree is naturally fruit- or nut-bearing, it will grow abundant clusters of its produce in easily-reached locations. For twice the base energy cost, the tree becomes semi-intelligent and semi-animate. It can twitch sheets of leaves out of the way to act as doors and windows, and rustle its leaves and creak branches to warn residents of intruders.

At TL 9, it becomes possible to genetically engineer plants to grow room-sized pods, even whole houses. The architect may design any wooden building, but may not include such electronic components as video walls or even power outlets, although conduits can easily be left in the walls for power and information lines. Cost to design and engineer a prototype "seed" is $5 per cubic foot of building volume. For a 10% increase in cost, the house can be equipped with one of each: filters to produce distilled water from moisture pulled through its roots, nutritious sap, and equally nutritious fruit and other produce. Once the seed is initially designed, copies can be made for 1% of the initial cost. Growing time is 1 day for 10 cubic feet of final volume. Finishing cost (for installing power cables, lighting fixtures, etc.) is $.1 per square foot of floor space.

Floating Buildings
Most properly, floating buildings (cloud cities, raft towns, etc.) should be designed with GURPS Vehicles. For example, levitating high-tech buildings, such as the floating cities in Larry Niven's Ringworld, should be built with contragravity or super-science levitation (p. V41). However, fantasy "castles in the sky" require a somewhat different enchantment than the one given for magical flying vehicles. Making a magically levitating building takes a spell similar to the one used to create a flying vehicle, but the energy cost is 40 per cubic foot of building. When the spell is cast, the building rises to an altitude determined by the caster at Speed 3, taking with it a chunk of dirt and rock with a diameter 10% greater than the building itself, and with a thickness equal to 10% of the building's height. Once it reaches its designated altitude, it will remain in that spot relative to the ground. The enchantment is broken only when the building is destroyed.

Windows and Vision

Buildings may have the same visibility classes as vehicles (see p. V25), although they have slightly different meanings. Good visibility is appropriate to a modern glass-sided skyscraper or glass-fronted shop. Every room with an outside wall will be completely exposed to the outside, barring interior obstacles (desks, cubicle partitions, etc.) and differing light levels. Most homes qualify as having Fair visibility. One can see in or out from most places in most rooms, but the corners of rooms with exterior walls and areas under windowsills are obscured from outside view. Warehouses and factories tend to have Poor or No visibility. Their windows are few, small, and often covered with frosted glass, letting in light but blocking vision.

Most low-tech buildings have far poorer visibility than modern buildings. Before TL 5, glass was prohibitively expensive, and windows were covered with a variety of shutters which let in some light and air while keeping out bad weather and, incidentally, blocking vision. Packed earth buildings may have no better than Poor visibility. Up to TL 2, stone, brick, and concrete buildings may have Poor visibility at best. At TL 3 and 4, they may have Fair visibility only at triple the regular structural cost. This represents "Gothic" vaulted construction and similar techniques that opened up building walls at an enormous cost in fine masonry. Wooden and thatched buildings may have Fair visibility up to TL 2, but they will be extremely open to the weather. At TL 3 and 4, they may install glass windows for an additional cost of $0.1 per sf of the building's surface area.

Buildings with opaque walls and Poor or worse visibility may have arrow slits, sometimes called loopholes. An arrow slit is an extremely narrow window which allows an archer (or gunner) to fire out of the building in relative safety. In buildings with thick walls, the slit must be narrow at one face of the wall (usually the outside), and wide at the inside. The archer can get very close to the slit and maneuver around it, gaining a broad arc of fire. An arrow slit may be any height (one to two yards was common), and may be as narrow as two inches. A character at the window has a sixty to ninety degree arc of fire, but may only be targeted from the outside by someone in the archer's line of fire that turn, and then only at an appropriate penalty for target size. The GM may declare an additional -2 penalty for difficulty seeing the target.


Building Time and Labor

In a pinch, it may become necessary to figure out how long it will take to build a building. For buildings at TL 5 or less, divide total building cost by 20. This indicates the number of man-days it will take. For TL 6 and above, divide the cost of the building by twice the TL squared (that is, 2*TL^2, not (2*TL)^2) to get the number of man-days necessary. Particular materials take less time to put up. Divide the time by two for concrete and polycarbon buildings.

To get the actual building time, divide the number of man-days by the number of people working. The GM is free to set labor availability as he will. Typically, a house will be built by a crew of less than twenty, while very large buildings (Gothic cathedrals, skyscrapers) may have construction crews of up to two hundred and massive civil engineering projects (the Pyramids, Hoover dam) over a thousand. It is very realistic for the GM to pro-rate construction, having the architect spend his funding in increments ("You spent $50,000 this month, and they finished the second floor...").

This presumes a crew with an average skill of 12. For thatch and wooden buildings, the appropriate skill is Carpentry. For stone and brick/mud brick buildings, the appropriate skill is Masonry, although up to ten percent of the crew may have Carpentry or Blacksmith instead. A number of carpenters are to build scaffolding and wooden forms for arches, while smiths are needed to tend tools and produce clamps and nails. At TL 6+, up to ninety percent of the building crew (one hundred percent for concrete and polycarbon buildings) should have Professional Skill: Construction Worker (P/A). At low TLs, a sizable portion of the workers on large building projects were unskilled (in GURPS terms, working from default), merely providing strong backs to haul and lift. For every point of average skill below 12, increase building time by 20% and reduce cost by 2% (unskilled workers come cheaper). The minimum average skill is 7. If the GM allows the builder to use a more skilled workforce, increase cost by 5% and reduce building time by 2% for every point of building skill above 12.

At TL 10, almost all building labor is automated. The robobuilder, a variant of the robofac, can be programmed with specifications and put up a building with minimal human oversight. A robobuilder can perform TL squared man-days of labor in 24 hours, and can operate for 5 days on an E cell. Dropped into an empty environment, it can dig tunnels, quarry stone, and otherwise make its own raw materials. Provided proper programming, a robobuilder can build buildings working completely from nothing, although it will work with one-quarter efficiency, and it cannot create completely new materials from nothing. For example, it cannot build wooden buildings on an airless asteroid. A robobuilder has 50% greater cost, volume, and weight than a minifac. By TL 13, buildings are built so quickly that they may appear to grow out of the ground in days or hours.

See example.

Composite Buildings

It is possible to make a building from several different materials. For example, a building may be built with a brick lower level and a wooden upper level. In general, any material may be used to build on top of another as long as it is not "stronger" than the material below it. The hierarchy of "strength," in decreasing order, is as follows:

• Stone, brick, concrete, polycarbon, metal
• Unmortared rubble
• Mud brick
• Wood
• Flexible