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?
One of 2 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
What your site needs
A north-facing window/room lacking other daylighting options, with space for the mirror assembly
A mirror on a motorised mount that follows the sun and reflects its light into a north-facing window. A room that never gets direct sun receives daylight and a little warmth. It is the most complex and fragile daylighting option, with electronics to build and adjust, so it suits a north room with no other way to get light.
5-10 years for the custom electronics (photoresistor, H-bridge driver) and motorized axes, explicitly flagged elsewhere as fragile and needing ongoing calibration
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Motorized heliostat mirror (north-facing daylighting) (This page) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Specialist · Upkeep: Heavy · Change to daily life: None · Works without the grid: No Choose it if you want sunlight in a north-facing room that never gets any.
Daylight-factor window sizing and placement Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: None · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you want enough daylight in every room, planned rather than guessed.
We don’t list sizing or quantities, as the yield of each technique depends on the quality of its build. The catalogue compares options but doesn’t dimension them. Regulatory notes are indicative, with a French example, and need to be confirmed locally.