This deliverable “Definition and selection of KPIs” is part of the ongoing work within the project BIOBUILD in the framework of WP1” Specific climate considerations and building typological classification”. The main aim of BIOBUILD is to accelerate the transition towards a circular and low-carbon construction sector by developing and deploying innovative, bio-based building components and solutions. Performance indicators (PIs) are fundamental to allow the comparison of different technologies solutions that can be used for building applications and evaluate the potential benefits in different aspects. This document collects a number of performance indicators that can be suitable for application from material to system level to quantitatively analyse various aspects of novel materials developed for building applications. The methodological approach followed should lead to the selection of the "key" ones that should be included in the project BIOBUILD. The first step of the KPIs identification was a deep literature review of the performance indicators (PIs) used to evaluate the performance of building components in different aspects. The selection of relevant parameters (KPIs) was then done considering the stakeholder perspective regarding the main objectives of the project. The set of PIs presented in this deliverable represents a proposal of reference parameters intended to guide and support the monitoring of progress across all work packages, ensuring alignment with project objectives. For instance, the development of materials, the demo testing campaigns, building simulations, and environmental evaluation will rely on the PIs and KPIs defined as a basis for performance assessment. The different PI and KPIs will ensure the target of technical, environmental, and economic specifications in the project BIOBUILID. This report is structured as follows: Section 2 reports the list of the performance indicators selected with methodology used. The results of the PIs evaluations and the listed KPIs are reported in Section 3. Conclusions of this report are in Section 4.