How to build a self-sufficient town

Question

Other questions have tried to address how big/small towns have to be in order to function, but I'm more interested in approaching it from a different angle: How big would a town have to be to support a given population?

Firstly, let me just clarify that by "town" I really just mean a place where people live, and not implying any arbitrary population cutoffs (as opposed to a village or a city).

For the purposes of this question, let's assume medieval era farming techniques and knowledge. Let's also assume that the town in question can do trade, but trade is infrequent enough (or the town poor enough) that while they could get the occasional tools or a new seed stock, they cannot rely on trade for essential things like supplementing their food supplies.

Given this, and assuming a reasonable variety of crops given the era, how large a plot could a farmer farm? (For bonus points, how much food, and what kinds, would he be producing here?) How much could that be increased by hired hands? For self-sufficiency, how many people would be needed to support this farmer (blacksmiths to make/repair his tools, carpenters to build his house, etc.)? How would this scale if we add a second farmer and plot? That is, do we have to have twice the number of blacksmiths and carpenters, or can a single "set" support multiple farmers?

I hope this one's not growing too broad; the gist is that I'm trying to find a way to determine population size based on the number of farms/farmers, or going the other way to find out how many farms/farmers I'd need to have, given a specific population. And, consequently, what the physical size of the town would be, including said farms.

Answer 1

In Medieval Europe there was a method of land ownership called Open Field or Strip Farming. In this method each home was "given" several strips of the large field on which to grow their own produce. In return they had to pay levies to the Lord of the Manor (who actually owned the land).

Because each tenant was responsible for their own food and because of the large amount of cooperation involved (different residents would supply different pieces of equipment such as the plough/oxen etc) This is probably one of the best solutions you're going to find. while not as efficient as the large scale industrial farms we have today they can be operated on a much smaller scale.

Theoretically all you need is a large enough population to provide the aforementioned equipment and animals and the village could be self sufficient. Of course once you start needing repairs/blacksmiths/food which cannot be grown the size of the village must increase.

The example I gave in the link above cites Elton in Cambridgeshire (UK).

The village of Elton, Cambridgeshire is representative of a medieval open-field manor in England. The manor, whose Lord was an abbot from a nearby monastery, had 13 "hides" of arable land of six virgates each. The acreage of a hide and virgate varied, but at Elton a hide was 144 acres (58 ha). A virgate was 24 acres (10 ha). Thus, the total of arable land amounted to 1,872 acres (758 ha). The abbot's demesne land consisted of three hides plus 16 acres (6.5 ha) of meadow and 3 acres (1 ha) of pasture. The remainder of the land was cultivated by 113 tenants who lived in a village on the manor. Counting spouses, children, and other dependents, plus landless people the total population resident in the manor village was probably 500 to 600.

My suggestion would be that if the village is a satellite to a larger town where supplies not made in the village could be bought from (and an insightful Lord who was willing to take responsibility for purchasing the equipment) the threshold for being self sustaining (at least as far as food was concerned) could be much much lower.

Answer 2

I am going to assume you're talking about a settlement in Europe during the Middle Ages. They would have old world crops, including things like cabbage, wheat, and kale. Corn, tomatoes, and potatoes would never show up in Europe until the Columbian Exchange happened. You can see what they ate here.

According to S. John Ross, in his web article called "Medieval Demographics Made Easy," the average population density was 30 per square mile. This is an average, but it will give you the sense of size a settlement of a given size needs to sustain itself.

Looking at the definition of an Acre, it's the amount of land a farmer could plough in one day. This being said, you should check out the article here. It has some numbers which talk about the Domesday Survey, which give you a good idea of how much people produced on their farms. As you can see in the article, there are some problems, but the above resources can give you a good idea of how large a settlement should be for a given population.

It appears most farmers farmed in a group of other farmers on plots of land around 120 acres. You could have 10-12 people working that land, so you could expect a farmer to easily maintain 12 acres of land. It's a lot of assumptions, but it will give you a good starting point.

Answer 3

Other answers talk about food which is certainly relevant, but as the question suggests there are other needs for self sufficiency. For example if we are looking at ploughing you are going to need to have harness for the animals ( and to get useful working lives out of them it should be well fitted ) and the equipment will need to be made either from metal or from a mixture of wood and metal, which means you need to have the resources and skills available to make them or you need to have trade routes to bring them in.

If you are looking at local resources rather than trade you probably need at least a blacksmith, a potter and a carpenter in your town. The value of the work of these individuals in your world will dictate how easy or otherwise it is for them to make a living but it is logical to suggest that there would be a minimum size of location that it would be economic for them to set up shop in terms of turnover. Of course it is not impossible for someone to be a blacksmith-farmer or a carpenter-farmer and there are many tasks that are going to be performed collectively, but if you want to have a truly independent town then they are either going to want to have these skills resident or to have travelling artisans who pass through every season or two and pick up the last few months worth of work.

In terms of work rate it is hard to judge, partly because the quality of the work affects the amount that is required and the speed with which it can be performed. How long it takes to build a plough or a house or a chair is very a much piece-of-string type of question but if you are interested in the techniques used historically a book called The Doctrine Of Handy Works is basically a very early DIY manual and contains a lot of interesting information on these topics.

If you don't have the trade routes you are also going to need supplies for your artisans to work with - certainly you will need building materials in any case, but without trade to bring in iron or clay you would need to be able to produce those in the local area and if you are smelting or firing them you will probably also need charcoal, so being in reach of forest would be helpful. This might indicate a forestry economy as well- woodcutters would be another likely trade. Building materials are quite flexible, but worth consideration because whether you have mud, brick, wicker, wood or dry stone available will strongly affect the architectural style of your town.

If you have livestock around you will also need people to look after them and, around working animals, to train them. Ensuring they are fed and kept healthy also requires land and expertise. Again these tasks might well be thought of as farming, but specialisation is an efficiency and with maintenance tasks like farriery and equine dentistry, you might expect that a town would have sufficient work for specialists in these fields.

Answer 4

Climate (adequate rain? too cold? too hot? too windy?), soil fertility, geography (rivers? with fish? flooding? tsunamis? seacoast? mountains?), local resources (wood, coal, iron-ore, etc), will all impact your settlement sizes.