# Search criteria

To optimize the sustainability advice the API is able to process a search criteria function next to target energylabel.

#### Search criteria - "search\_criteria"

The search criteria used for the sustainability advice. The different criteria can yield different results. 

* Syntax: 'search\_criteria' 
* Required: No
* Values: Integer, 1 to 4
* Default: 3 
* Description: 
  * 1 = lowest investment costs 
  * 2 = lowest energy costs 
  * 3 = highest return on investment
  * 4 = lowest BENG2 score (highest energy label)

**User input-based result selection**

The final result is based on the user-defined criterion, along with any set restrictions, such as maximum investment or target energy label.

* **Max investment**: Filters results where the total investment required is below the set limit.
* **Target label**: Filters results where the energy label meets or exceeds the target value.
* **Strict target label**: If "energylabel\_strict": 1, only results exactly matching the target label are returned.
* **Criterion-based selection**: After filtering, the criterion determines the final result.

Criteria options:

* **1: Lowest investment cost** - Result with the lowest total investment required. This results in measures which will generate just enough BENG2 improvements to meet the target energy label .
* **2: Lowest energy cost** - Result with the lowest annual energy expenses focusing on measures which reduce the monthly energy bill the most.
* **3: Highest return on investment** - Returns the result with the highest financial benefit within the energy label range.
* **4: Lowest BENG2 score** - Property with the lowest BENG2 score, indicating the best energy performance.