> 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/workflows/daylight/daylight-info/green-star.md).

# Green Star

## What is Daylight in Green Star?

Daylight in Green Star focuses on delivering well-lit spaces that provide high levels of visual comfort to building occupants. Points are awarded when project teams can demonstrate that a specified proportion of a nominated area receives high daylight levels. 

## Compliance Using Daylight Factor

Daylight Factor can be used as follows:

> *"High Levels of daylight are deemed to have daylight factors above 2.0% for all spaces, except living rooms and dining rooms in residential primary spaces, where the threshold is a 1.5% daylight factor."*

When calculating the Daylight Factor, Green Star recommends using either a CIE overcast sky or a CIE uniform sky, and the grid is either at the finished floor level or 720mm above FFL.

## Compliance Using Daylight Autonomy

Daylight Autonomy can be used as follows:

> *"High Levels of daylight are deemed to have at least 160 lux due to daylight during 80% of the nominated hours."*

Green Star recommends that simulations must be completed for at least every hour during the Nominated Hours.

{% hint style="info" %}
The project team must demonstrate that the software used to determine compliance is based on the [Radiance](/support-and-training/other-support/testing-and-verification/radiance-v-5.2.md) simulation engine and that it uses the statistical sky, the daylight coefficients, the Perez All-Weather Sky model, or the annual CIE sky simulation algorithms.
{% endhint %}

## Modelling Daylight for Green Star in Speckel

To meet the requirements of Daylight for Green Star, the Purpose of the [Space](broken://pages/ThMmKt5OlSJ6KmC2TwpQ) must be defined within the model for that Space to be selected for assessment. In this case, the 'Living Spaces' must be defined with a [Purpose](broken://pages/dVGTIfnbNp9Pm2bQvXbl). Once defined, the [Daylight form](https://support-and-docs.gitbook.io/speckel-docs/user-manual/building/simulation/daylight) is used to nominate the [Metric](broken://pages/vLwTpQcI3D3mRAeAW7QT), [Grid](broken://pages/ZmDyt32so5DHQ4fHrKZm), [Surface](broken://pages/yhjFsYcMrvvbRRTuDHBx) and [Simulation Settings](broken://pages/H2o1xCL2NAseSjcTacNB) before running a simulation. For the Metric, inputs must be configured per Green Star's requirements. See your Greenb Star documentation for up-to-date information. 

<figure><img src="/files/E1ooazQZl8EAZGT6o9Gx" alt=""><figcaption></figcaption></figure>


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