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?

Low-grade heat

Gentle warmth below the temperature needed for hot water or cooking: sun through a window, heat given back by a thick wall, warmth from compost or used water. It preheats and tempers, and costs nothing.

Produced by

• South-facing glazing sized for winter gain
• South-facing attached sunspace / solar greenhouse
• Mechanical ventilation with heat recovery (MVHR)
• Active compost pile
• Decentralised single-room heat-recovery ventilators
• Motorized heliostat mirror (north-facing daylighting)
• Slate-clad solar air heater (wall-mounted thermosiphon collector)

Diverted, rerouted by

• Exposed thermal mass (masonry, rammed earth, slab)
• Water-based thermal mass (drum / water wall)

Consumed, transformed by

• Compost-coil water pre-heater
• Ground-coupled hydronic cooling loop (buried pipe + radiator)
• Night-sky radiative cooling