## 2 Background
### Smart Readiness Indicator  
Smartness concerning a building can be referred to as a building's ability to sense, interpret, communicate, and actively respond efficiently to ever-changing environments concerning three main aspects: technical operation of the building, external factors like grids and the building occupants [23]. Smart buildings are a result of digitalization efforts made toward how energy is generated, transmitted, and utilized with regard to buildings [24]. Smart buildings are part of the larger scheme which includes the synergies among the energy, Information, and Communication Technology (ICT) industries. This synergy has allowed for the development of smart grids being connected with smart buildings as well as with renewable energy generation sources. It has also allowed buildings to become better equipped with fluctuating demand while also becoming prosumers in cases of low demand. In this new paradigm, smart buildings need to perform at an optimum level to meet the demand and still be energy efficient. For this purpose, many indicators and metrics have been developed to judge a building's performance from different aspects. Many sustainability rating systems have been developed to judge a building's performance. From a holistic point of view, there are three major categories of this type of rating system. Cumulative Energy Demand (CED) systems only focus on energy consumption criteria. A good example of CED is the Energy Performance Certificate (EPC), which is internationally standardized and was introduced under the European standard of EN 15217 [25]. The purpose of EPC is to standardize regulations and encourage people to improve the energy performance of buildings. In the EU, Finland uses EPC as a legally mandatory rating scheme for buildings. In EPC, the value for E is calculated by evaluating factors like outer walls, doors, windows, roofs, floors, heating systems, domestic water systems, ventilation systems, lighting, cooling systems, additional electrical heating systems, and other systems affecting building energy usage [26]. The second type of sustainability rating system is Life Cycle Analysis (LCA), which has a focus on environmental factors like emissions only [27]. Total Quality Assessment (TQA) is a multi-criteria system that focuses not only on the economic but also the environmental and social factors [28]. A good example of TQA is Green Public Procurement (GPP), which was introduced as a result of guidelines for TQA by the European Commission. GPP is not necessarily a rating system; rather, it gives sustainable and environment-friendly suggestions related to material procurement for buildings [29]. The GPP system is based on two versions: one is the core, which offers a much easier implementation of the methodology. And the comprehensive one offers an extensive implementation of the methodology. Another scheme under TQA is the Building Research Establishment Environmental Assessment Method (BREEAM), which was established in the UK. It is a certification scheme. BREEAM is based on extensive life-cycle sustainability performance criteria for buildings including land use, material use, and pollution [30]. The main objective of BREEAM is to reduce life-cycle impact, recognize environmental benefits, and encourage the demand and value of energy-efficient buildings. Another example of a sustainable rating system is LCA, and the International Common Carbon Metric by the United Nations Environment Program's Sustainable Buildings and Climate Initiative (UNEP-SBCI) is the most popular. It aims to assess emissions related to buildings. Moving forward from sustainability rating systems, there are various rating systems for buildings that do not just focus on one parameter and fall into multiple categories. The Smart Readiness Indicator (SRI) is one such rating system. The SRI primarily focuses on the technical aspects of a smart building.