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 / light tubes

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

Roof access for the collector dome, and a vertical run to the ceiling penetration below

Reflective tube channels daylight from a roof-mounted dome into a room with no exterior wall access.

Cost

Medium

Upkeep

None

Skill to build

Basic

Lifespan

20-30 years for the reflective tube and dome (UV degradation of the dome plastic is the main failure mode)

Embodied carbon

Low

Space / material use

Low

Output timing

Weather/time-dependent

Skill to repair

Basic

Inputs

• Solar radiation

Outputs

• Daylight

Compare the 2 ways to meet this need

Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.

• Solar / light tubes (This page)
  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.
• Clerestory windows / light shelves
  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.

Sources

• General solar/light-tube manufacturer durability consensus

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.