> For the complete documentation index, see [llms.txt](https://docs.betterbuilding.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.betterbuilding.io/user-guide/elements/add-a-material.md).
# Add a Material
A material describes the properties of a building component that influence its thermal, moisture and optical performance. It’s a key element in simulating and analysing how a building design will perform in terms of energy use, moisture management, daylighting and carbon impact.
## Add a Material
To add a material, click the '+' button. This opens up the material layers panel. A material layer is simply a group of materials, which can include either supplier-provided or generic options. Supplier materials have been reviewed by Better Building to confirm they meet the minimum compliance requirements of relevant building codes. Our generic materials reflect typical data for each region, helping you build with confidence when specific products aren’t being used.
In the example below, a membrane material layer is selected, and the generic material 'Class 4 – Vapour Permeable Membrane – 3.9 µg/N.s' is chosen. Once added, the material appears on the internal side of your Wall, Roof or Floor System.
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