Multi-use homestead outbuilding

So I've been tinkering with a design for a multi-use outbuilding. Thinking way too much I suspect.

In the past we built several goat shelters, a chicken pen, a chicken tractor, along with milking stanchions for goats and another for a cow. We also planned the design for our pole barn. I never did get around to building a greenhouse, but I did finally finish my grape arbor.

So I'm trying to combine things I've learned from experience with things I've learned from others, and create something new. Or at least interesting. I'm not sure if I've succeeded at either, but I've at least kept myself entertained and occupied through this long winter.

Below is what I came up with. This is a first pass. Suggestions and constructive criticism are always welcome. Also, if I ever build it, it could use a catchy name.

--

Design:

The structure will be a long, narrow outbuilding composed of five square compartments or pens aligned in a row, running along an east/west axis. Each pen will have an interior space a little over 5 feet on a side, giving about 25 square feet of floor space. Each pen will have a 32-inch "doorway" in the center of the south wall. One pen should be able to provide shelter for up to six standard sized goats, or up to a dozen chickens, assuming they are given adequate run or pasture space.

click image to enlarge

Each of the five pens will serve a particular role in a given year, and functions will shift each year, giving a five-year rotation. The five functions are: Goat shelter, chicken coop, compost finishing, greenhouse, and woodshed.

The lower portion of the pens will be three courses of standard 8'x16' concrete blocks, but double the usual thickness (i.e. 2 blocks side by side or 16 inches thick). Standard dimensional lumber will be used to create a simple framework for the upper part of the structure.

The upper walls and roofing material will vary by function, as follows:

click images to enlarge

Goat shelter: The walls will be made of stacked straw bales. The roofing will consist of corrugated metal attached to lightweight (2x2) wooden frames. The roof will be designed with a slight slope for water runoff. It will overhang the straw bales slightly in all directions.

Chicken pen: The chicken pen, like the goat shelter will have straw bale walls and corrugated metal roofing on lightweight frames. However, movable nesting boxes will be inserted into the north wall in place of one of the straw bales. The nest boxes will be constructed to match the typical dimensions of the bales. A wood-framed door covered with chicken wire will be used to close the pen at night. Branches or rods can have both ends stuck into the straw bales to act as perches for the chickens at night.

Finishing compost: The compost area will consist of the remains of the goat bedding from 2 years prior, the chicken litter from the prior year, and rotting straw bales used for walls in previous years. Any excess rotted straw bales will be laid around the outside of the structure to act as insulation (and additional compost/mulch). This area would have minimal roof and wall coverings beyond those shared with neighboring pens.

Greenhouse: The roof, walls, and door of the greenhouse will be glazed with lightweight, durable material (polycarbonate maybe?) attached to lightweight frames. However, the rear (north) wall of the greenhouse will be painted plywood. Just inside the plywood, on top of the double-thick block walls will be 55-gallon rain barrels. They will be used to store rainwater. The barrels will supply water for the goats, chickens, and plants in the greenhouse. The warmer environment of the greenhouse will reduce the chance of the water freezing, and the thermal mass of the water will reduce temperature extremes within the greenhouse. The concrete block side walls should be entirely enclosed within the greenhouse, allowing for more shelf space. The concrete block could also be used as bench supports for shelving that extends the length or width of the greenhouse.

Woodshed: The woodshed area will have lightweight covering of whatever material is available, to keep rain off the stored wood. If extra glazing material is available to be used for this area, it would minimize the possibility of casting shade onto the greenhouse. However, caution should be used to make sure the stored wood is not subjected to excessive humidity.

Functional Rotation:

Each spring, the functions of each pen will shift one pen to the west, as follows:

Year 1: |  goats   | chickens | compost  |greenhouse| woodshed |
Year 2: | chickens | compost  |greenhouse| woodshed |  goats   |
Year 3: | compost  |greenhouse| woodshed |   goats  | chickens |
Year 4: |greenhouse| woodshed |  goats   | chickens | compost  |
Year 5: | woodshed |  goats   | chickens | compost  |greenhouse|

The upper portions of the pens would need to be taken down and moved as needed, which explains the emphasis on lightweight materials. However, the actual amount of work should not be great, since two of the pens have straw bale walls, which, if rotting, can simply be knocked down in place. The compost area has essentially no walls. The remaining roof panels and wall panels should be built in such a way that they can be moved easily. The rain barrels can be emptied for moving. The rotation should happen in spring, when rainwater should be plentiful.

The rotation is designed to cut down on incidence termites in the wood storage area, manure-borne parasites, while keeping a constant supply of fresh, rich soil for the greenhouse, and hopefully cutting down on all types of pests and pathogens.

The logic of the rotation is as follows:

The goat pen will build up a certain amount of bedding and manure over the course of a season, especially in winter. By moving the chickens into the goat area, the will scratch the bedding somewhat, encouraging the composting process, while at the same time adding fresh material in the form of droppings and litter. In the third year, this material, along with old straw bales, will finish composting, while still providing plenty of mulching material for the gardens. In the fourth year, the finished compost can be spread to the gardens and used with greenhouse plantings. The fifth year will be something of a "fallow" year, acting only as a dry place to store firewood through the winter.

In the warmer months, when no firewood storage is required, the pen could be set up as a milking area for the goats. In the winter, the milking station could be moved to the warmer greenhouse area.

By keeping the chickens and goats side-by-side four years out of five, the fencing needs are simplified. The chickens and goats would not be restricted from entering each other's pens during the day. Flexible stock panels could be used to channel the goats and chickens to pasture areas.

--