Powers and Perils

Construction Rules

Derived from an article on GURPS Pre-industrial Architecture by Matt Riggsby, converted from the "death by detail" GURPS measurements. :)

Unlike GURPS (which narrowed it all down to the square yard or cubic yard, including window and door spots, these rules are provided as an easy means to get a thumbnail cost and time for construction. The GM is free to add a "fudge factor" to account for other stuff.

Labor Costs

Bearer 1SC/month
Thatcher 15CC/month
Quarryman 15CC/month
Lumberjack 2SC/month
Brickmaker 25CC/month
Carpenter 4SC/month
Mason 5SC/month
Architect 2GC/month

Construction/Engineering Task Modifier Tables

Site Quality Labor Modifier #E
Wide Open and Level .75
Some brush, gentle slope 1
Rolling Land 1.25
Thick Vegetation 1.5
Ruins or Demolished Structures 2
Congested Urban Area 2.5
Swamp 3
Mountainous Rainforest 4
Underwater 5
Hellish 7

Equipment Quality Labor Multiplier #E
Everything they want and then some .7
The supervisors Wish List .8
State of the art .9
Well Equipped 1
Foreman read catalogues and sighed 1.2
Moderately Equipped 1.5
Minimally Equipped 2
Little mechanical assistance* 2.5
No mechanical assistance* 3.5
Mostly "field expedient" tools 5

*Mechanical assistance includes things like winches, cranes, or animal power, when required for the task at hand.

Environmental Conditions Labor Multiplier #E
Indoors .9
Shirtsleeve comfort 1
Heavy Clothing 1.1
Very Hot 1.25
Very Cold 1.5
Very Cold, with protective gear 2
Very Hot, with protective gear 2.5

Crew Quality Labor Multiplier #E
Elite Military Engineers .4
Military Engineers .6
Top Notch professionals .8
Professionals 1
Unskilled laborers with good leaders 1.2
High spirited amateurs 1.5
Spoiled and lazy union 2
Co-opted Peasants 3
Slaves/Prisoners 4
Disgruntled Slaves/Prisoners 5



Thatching is made from reeds, grasses, or long leaves bound or woven together to form larger and more durable bundles or mats. Thatch tends to replace dried earth in buildings in wet regions and 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 the preferred roofing material for domestic architecture, since it is cheaper and easier to install than other materials.


Wood is probably the most versatile of building materials, stronger and more durable than thatch and earth, lighter and easier to work than brick and stone.


There are two kinds of earthen materials: piled earth and hard earth. Piled earth is simply dirt dug out of the ground heaped up in a mound or wall. Piled earth is good for improvised fortifications but little else. Hard earth, including rammed earth, sun-dried mud brick, and wattle-and-daub (dried mud over reeds or grass) is the preferred material for many small buildings at low cultural levels. However, both forms 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.


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. Brick, in the form of flat ceramic roofing tiles or brick arches and vaults, may be used as a roofing material.


Strong and durable, stone is the preferred material for public buildings and fortifications. While it is mostly seen as a wall material, stone may be used as a roofing material, usually in the form of sheets of slate, gypsum, or other rock with sharp cleavage planes.


With barbarian cultures, the only "mortar" available was wet clay, which could be used to smooth surfaces and hold mud bricks together more firmly. For more advanced cultures however, limestone and other calcareous minerals could be heated to yield powdered lime, the basic ingredient of plasters and mortars.


Materials are rarely found where they are needed, so transport is an important consideration, and can often be costly. The labor necessary to move materials around on the building site is included in the building labor figures, but additional labor may be necessary to get the materials there.

Transport by water is far more efficient than transport by land. Prices will, of course, vary wildly, but long-distance shipment of materials over sea can cost as little as 0.3BB per ton per strategic hex if the builder intends to fill the entire hold of a ship. Poor weather, piracy, and duties can increase this somewhat. Shipment by boat or raft up rivers and canals is also relatively inexpensive, with the price increasing to perhaps three or four times that.

Shipment by land is the most expensive. Moving materials by oxcart will cost in the neighborhood of 5BB to 8BB per ton per strategic hex, which can increase tremendously if the cart has to travel over poor roads or through bad weather.

Material Costs

The costs of the following materials are based on the cost of labor to produce them, given the rates of production in Matt's GURPS document. All quantities have been pro-rated and simplified for ease of use. All prices assume materials are on the owner's land -- if the raw materials are on another's land increase costs by 50-100%, not including transportation costs.

sf=square feet, cf=cubic feet

Thatch100sf3BB800#6h4" bundles
Pine Lumber100sf7BB140#9h1/2" thick
Oak Lumber100sf8BB180#10h1/2" thick
Mud Brick50cf4BB4,800#5h200 blocks
Fired Brick50cf*18BB6,000#10h1500 bricks
Stone Rubble50cf8BB5,000#15h
Ashlar Stone50cf7CC7,500#125h
Mortar5cf*5BB675# 3h
*includes cost of firewood needed to fire the material

Construction Costs

The costs of the following structures are based on the labor costs, plus the above material costs. All structures below are 10'x10' in size. Stone and brick structures include an additional 10% of foundation.

For the times below, the second number includes the time to produce/gather the construction materials, if not done beforehand.

Wood Frame15BB9h/14hUses 50sf of soft wood
Thatched Frame 2CC12h/20h4" thick
Pine-faced Frame35BB10h/33h4" thick
Oak-faced Frame 4CC10h/35h4" thick
Mud Brick Wall 15BB6h/11h6" thick, 1 story limit
Mortared Brick Wall5CC17h/27h6" thick
Unmortared Rubble* 75BB25h/50h18" thick, 2 story limit
Unmortared Ashlar 1SC15h/130h6" thick, 4 story limit
Mortared Rubble 25BB8h/25h6" thick
Mortared Ashlar 11CC19h/135h6" thick
Ground Clearing, open4BB10h1,000 sf
", rough 4BB10h500 sf
", forested 4BB10h100 sf
Excavation 13BB37h1,000 cf
*Price and time for 1 story -- QUADRUPLE time and cost for two stories and DOUBLE thickness.

For roofs take the ground area of the building and add 50% to determine the actual area. This applies to thatched or wooden roofs. For Mortared brick (clay shingles) or mortared ashlar, use HALF the determined area.

For ground floors, use wood frame as noted, fired brick at 1/3 cost and time, or mortared stone at 1/6th cost and time. Upper-level floors use wood frame, fired brick or mortared stone as noted.

These costs are all base, no frills costs -- time (and labor costs) will increase with any decoration or higher quality materials.

EXAMPLE - A peasant house, a 15x20 pine wood faced frame with thatched roof and wooden first and second floors (upper floor is considered 1/2 a story).

Walls 15x15 (end) x2, + 15x20 (side) x2 = 1050 sf = 10.5 panels.
Floors 15x20, x2 = 600sf = 6 panels
Roof 15x20, +50% = 450sf = 4.5 panels

Total framed wood is 16.5 panels, or 577BB (58CC). Time is 165 hours.
Total framed thatch is 4.5 panels, or 9CC. Time is 54 hours.

This house will cost 67CC to construct if built with materials on the owner's land, or from 1GC to 13SC to construct if materials need to be brought in. Total time is 219 man hours (10h per day, this is about 22 man days). If you have to cut and prepare your own materials, the time is 635 man hours, or 64 days.

EXAMPLE - A Noble manor, 50' by 30' by 2 story, of mortared ashlar walls and roof. inner walls are oak-faced frame (guessed with two running the width of the house, 1 running the length.

Walls 30x20x2 (ends) + 50x20x2 (sides) = 3200sf = 32 panels MA
Roof 50x30 x 0.5 = 750sf = 7.5 panels MA
Internal walls 30x10x2x2 + 50x10x2 = 2200sf = 22 panels FW.
ground floor 50x30/6 = 250sf = 2.5 MA
second floor 50x30 = 1500sf = 15 panels framed wood

The manor will cost 462CC (stone) + 148CC (wood) = 610CC, or 61SC. This is a base price and probably should be multiplied by a few times for decoration. Time to create this manor is 1168 man hours (117 man days) if the materials are already available, 6965 hours (697 man days) from scratch.

Burton Choinski