Have you ever noticed how the low angle of the rising and setting sun can really heat up your house? Living in the Sonoran desert, it’s hard to avoid noticing when your house starts to heat up before 8 am!
However, trying to block that sun can be tricky due to the angle. While trees provide shade overhead, that low sun is going to slip right under them. It’s the same with porches on the east and west side of the house - the sun will sneak under those porches early in the morning and in the evening.
So what can you do?
In my case, my solution was to design a multi-purpose shade house that runs across the back of the house. It contains my plant propagation area, outdoor shower and the hen yard with two built-in compost piles. The idea was that the structure itself, along with some trellised grape vines (deciduous in winter), would help keep the sun from hitting the east side of my house in the morning, preventing that early morning heat gain that’s so undesirable in the summer months.
I tried to address as many permaculture principles as possible in creating this project. The following principles really stand out:
- Observe and Interact – I observed that the low rising sun was prematurely heating up the mass of my house early in the day and transferring that heat inside. In the hot desert summer, this was costing me money on extra electrical usage.
- Catch and Store Energy – In the summer, I want to deflect the sun’s energy away from the house (to save on the amount of electricity I use cooling my house). In the winter, I want to capture that sun for passive solar gain. Deciduous vines are perfect for this.
- Obtain a yield – Eggs, grapes and compost are all generated in various parts of the shade house. Plus I save money on electricity and water because the shower greywater waters my grapes.
- Integrate Rather Than Segregate (also known as “Stacking functions”) – This design is a fairly decent application of “stacking functions” whereby each individual element in the system supports several functions and each function is supported by several elements. While the ultimate goal of the project was to passively shade the eastern façade of my house and save money on electricity, the shade house in its entirety does more than that. The combination of the structure and plantings does shade this façade in summer and still lets light through in the winter. The plantings are watered by the outdoor shower. The floors of both the henyard and propagation area are infiltration basins that collect rainwater runoff from the roof and compost woody mulch in place. The two compost bins in the henyard receive kitchen and yard waste and are turned by the hens. That compost is used in a potting soil mix for the plants grown out in the propagation area and also as top dressing for the vegetable beds.