Lowtech Graph lists low-tech options for every need of a home. Here you can compare them, find tutorials to build them, and link them together into a circular system. Why low-tech?
Solar gain avoidance / shading (summer)
Stops solar heat arriving in the first place. The summer half of a pair with passive solar gain, and distinct from active cooling, which removes heat that has already got in.
Adjustable brise-soleil / shutters (east-west): Movable shades, louvres or shutters on east and west windows. The low morning and evening sun comes in sideways, under any roof overhang, so these are angled or
Deciduous vegetation shading: Trees shade in summer leaf and admit sun once bare in winter; slow to establish, zero embodied carbon.
DIY shade-sail window screen: A piece of shade cloth cut and hemmed to size, hung on hooks outside a window or glass door. It stops the sun before it reaches the glass, so the heat stays out
Cool (high-reflectance) roof surface: A light, reflective surface on the roof. It bounces most of the sunlight back to the sky instead of soaking it up, so less heat reaches the rooms below. It can
Attic radiant barrier: A shiny foil fixed under the roof, facing an air gap. It turns back the heat that a hot roof radiates downward, so less reaches the insulation and the rooms. It
Vented roof / attic assembly: Vents low at the eaves and high at the ridge, so air flows through the roof space. The moving air carries away heat that builds up under the roof, and the damp