Structures and Appropriate Technology

A structure is the most expensive and least flexible thing you will put on the land. A swale can be re-cut, a bed can be moved, a crop can be changed next season. A shed on a bad foundation, or a store on the wrong side of the slope, is a mistake you live with for twenty years. So structures come last in the design, after water, access, zones and the fertility plan are settled, and each one is built only when something already on the farm needs it.

Materials, and what the land already pays for

Timber, stone, clay, straw, sand and gravel. Everything a small structure needs can come off the site or from a short haul, and each has one honest weakness rather than a hidden one. Timber moves as it dries and rots where it stays wet. Stone is heavy to move and poor in tension. Clay and straw are cheap and want a roof that keeps the water out. None of them needs a manufacturing supply chain to repair.

Salvage sits between the two. Reclaimed windows, roofing sheets, timber and hardware cost time and transport rather than manufacture, which on a cash-poor farm is the right trade. Salvage also carries costs the price tag hides: storage while you wait for the rest of the job, mismatched dimensions, and no rated performance. A salvaged beam of unknown species and unknown history is not a structural member until somebody competent has looked at it.

Thermal performance without jargon

Heat moves three ways and each has a different fix. It conducts through solid material, so you slow it with insulation or with mass. It moves by convection in air, so you stop it with draught proofing and a continuous envelope. It radiates from warm surfaces to cold ones, so you manage it with shading and with surfaces that face the sun.

Mass and insulation do opposite jobs. A thick stone or earth wall takes hours to warm and hours to cool, which flattens the day's temperature swings and suits a store, an animal house or a dwelling used every evening. Insulation slows the flow, which suits anything you want held near one temperature.

Orientation does most of the work before any material is chosen. A south wall collects useful heat from late morning to mid-afternoon in winter and can be shaded to nothing in summer by an overhang or a deciduous tree. The Roman writers sized buildings to purpose in exactly this way.

Cato's rule for scale is one line worth carrying: "let your buildings be proportioned to your estate, and your estate to your buildings." Varro makes the case from the other end, that a steading built too large is "eaten up by the expense of maintenance," while one built too small loses the harvest for want of a granary.

Appropriate technology is a constraint, not a mood

Any tool, machine or system on the farm has to pass one test: can the household maintain it, repair it, and power it through a bad year without a supply line from somewhere else?

By that test a good scythe beats a string trimmer, because it can be sharpened on the farm and needs no fuel. A hand pump beats an electric one if the grid is not guaranteed. A chainsaw is a fine tool on a farm with a fuel budget and a source of parts, and a liability on a farm with neither. Photovoltaic panels are worth having on a site with good sun, and only if you know what the household will do when the inverter fails, because there is no local repair.

Every tool you cannot fix is a small open loop, and a farm with too many open loops is not autonomous however much of its own food it grows. Which level of technology is right is a local answer that depends on skills, cash and what the neighbours can do.

Siting and the order of building

Water first, access second, structures third. Every structure sits on ground that drains, on the contour route you already marked, and where the winter sun reaches it. A foundation on wet ground fails, and a store on the low side of the slope takes the runoff from above it.

The order that works on a small holding is store, tool shed, animal housing, then the house. The store comes first, because grain, seed, tools and preserved food need a dry, cool, defended place before anything else multiplies, and a bad store wastes a whole year's harvest in a way no other mistake does.