Moderate room temperatures in high and low altitudes by using extremely low cost, recycled and widely available 'costales' (plastic mesh corn/rice sacks).
This simple solution can be replicated easily by people with no technical experience or literacy. Costales folded to be between 4-8 layers can be sustained underneath a tin roof with a grid of wire. An aesthetic layer of cloth, reed mats, or wood can seal the insulation from view.
Appropriate Technology Collaborative and University of Michigan Engineering Students 2015.
Led by John Barrie and Monika Goforth
Nueva Santa Catarina Ixhuacan, Solola, Guatemala