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?
Clerestory windows / light shelves
Passive
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 design allowing a raised roof section or elevated window band
High windows set near the ceiling, or a reflective shelf fixed partway up a window. The light enters high or bounces off the shelf onto the ceiling, and from there reaches deep into the room. The back of the room gets daylight without the glare and heat of a big window at eye level.
Build it
Nothing separate is built here: this is a choice about how the home is designed or used.
Cost
Medium
Upkeep
None
Skill to build
None
Lifespan
Matches glazing/roof-penetration lifespan (a design element using standard glazing units)
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Clerestory windows / light shelves (This page) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: None · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you want daylight deep into a room, without glare.
Solar / light tubes Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Basic · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you want daylight in a room with no outside wall.
Sources
EN 17037:2018+A1:2021 "Daylight in buildings", clause 5.1 (daylight provision assessed over the depth of the room, which is what a clerestory or light shelf extends). Standard, not freely available
Limitations of this page
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.