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?

Rainscreen cladding with drainage gap

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.

Outer boards or panels fixed with a ventilated gap between them and the wall behind. Rain that gets past the boards runs down the gap and dries in the moving air, instead of soaking into the structure. The walls stay dry and last much longer.

Cost

Medium

Upkeep

Occasional

Skill to build

Basic

Lifespan

Cladding material-dependent (see naturally durable or treated cladding); the drainage-gap detailing itself doesn't wear out separately

Embodied carbon

Medium

Space / material use

Low

Output timing

None

Skill to repair

Basic

Regulation (FR example)

Changing the external appearance of an existing building normally requires a prior declaration (declaration prealable) at the mairie; stricter rules and an architect consultation apply within a protected or heritage perimeter.

Inputs

none

Outputs

• Reduced fabric deterioration

Compare the 2 ways to meet this need

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

• Rainscreen cladding with drainage gap (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: Light · Change to daily life: None · Works without the grid: Yes
  Choose it if your walls face driving rain and you want them to stay dry and last longer.
• Generous roof overhangs
  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 the cheapest rain protection there is, designed into the roof.

Sources

• Building America Solution Center, "Drainage Plane Behind Exterior Wall Cladding" (PNNL / US DOE)

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.