Earthship Colony

This used to be a very different idea, but through a few iterations, it moved into the realm of feasible.

Core Concept

Dorms for adults. Every unit is comprised of some number of room and bathrooms. Rooms are all 12x12. The smallest (and most common) unit is 2 rooms, one bath. The idea that and individual or couple has a bedroom and a sitting room. Rent include food and access to facilities (laundry, small kitchen, etc.). For a little more, it includes services, basic housekeeping and a gardener (the units use grey water reclamation, so they all have a small indoor garden.

To manage and expand this will require a whole business, several actually. House keeping, kitchen, construction and utilities. From there, it makes sense to extend kitchen to farming/gardening to bring down the price of fresh fruit and vegetables. And construction can extend to wood working and lumber.

Layout

The main section will only be an acre or two. Some number of units plus all the support buildings. More area will be taken up by gardens and farms. Beyond that, a huge area will be taken up by forests. The forests are mainly to provide lumber, but they can incorporate permaculture to provide food as well.

Employment

The idea is that most people involved both live and work here. It's not a requirement (either direction) but it's the goal. In order for that to be sustainable, there must be exports. Based on the requirements above, the two most logical exports are food and wood products. Both can range from raw to processed goods.

The Maths

The question is how many people do we need in order to make something sustainable.

Lumber

A sustainable forest can produce about 1/2 cord/year. The heart wood can be used for lumber products, the rest can be used in a variety of other ways - composted, wood chips or burned to heat water or produce electricity.

There are several relevant formulas here that need variables filled in. What is the maximum useable lumber production per acre*year? At that level, how much secondary (burnable, etc.) lumber is produced? How much electricity does a cord of wood produce? How much wood/resident*year is required? What is the maximum $/cord (sell as firewood, sell as kiln dried lumber, make into furniture)?

Food

We can grow raw foods and purchase raw foods. Raw foods can be sold or processed. Raw and processed foods can be consumed by residents or sold. The question becomes what is the cheapest way to produce enough healthy, tasty food for residents and what has the best ROI when sold.

Other ROI

Considering my background, it may make sense to incorporate software development, not because it's a per-existing requirement (it's clearly not) but because it has a very high ROI, it will probably beat lumber and food. So we employ enough people to run a small software shop, and that produces enough revenue to cover the services they consume. We can extend this, any business that we can run with a high ROI is advantageous.

Everything

It ends up being a calculus problem, like rocket fuel. Assume we need to provide services to one resident. We need one person managing lumber, woodworking and construction. One person managing kitchen and garden. One person doing housework. And one person managing utilities.

So we need four people. If we have four people, how much money leaves the system per year. Some goes to taxes and some goes to things that must be purchased. How much income can be generated by the person managing the kitchen and the person managing construction. Also, there is (initially) some loss to paying off the investment. Say construction costs $1,000,000, we may be paying 5%/year or $50,000.

With enough data, we should be able to reasonable predict how much profit is produced per resident*employee. But it's a threshold problem. Maybe one kitchen staff can service up to 15 residents, but at the 16th resident, you need 2 kitchen staff. But 2 maybe able to handle more than 30, maybe they can handle 45. Eventually it evens out.

For example, let's say ROI on excess labor in lumber, construction and kitchen is $25/hr or $50000/emp. Utilities are 1emp/20residents, lumber is 1emp/5construction, construction is 1emp/30residents, farm is 1emp/1kitchen, kitchen is 1emp/20residents, housekeeping is 1emp/30residents, management is 1emp/25emp. Overhead is $5000/emp, plus the $50,000 on the investment.

I have to take into account income loss. Util, house keeping and management cannot convert excess labor to revenue.

See sheet. It works out pretty well right around 40 residents.