Pilot Assessments of the Smart Readiness Indicator of Buildings

Eight countries are currently assessing the SRI of 1,200 buildings within the EU LIFE project SRI-ENACT. To date, the highest number of assessments have been completed in Bulgaria. This article presents the interim results and conclusions of these assessments.

Keywords: SRI, smart readiness indicator, Bulgaria, buildings, SRI-ENACT

SRI Assessment Framework

The term ‘smartness’ as it pertains to a building refers to its ability to sense, interpret, communicate and respond in an efficient manner to changing conditions related to the operation of technical building systems, the external environment (including energy grids), and the demands of the building’s occupants [1].

By 30 June 2027, the European Commission will introduce a common EU scheme for rating the smart readiness of non-residential buildings with an effective rated output of heating systems, air-conditioning systems, systems for combined space heating and ventilation, or systems for combined air-conditioning and ventilation of over 290 kW[2]. In the meantime, the Commission recommends that Member States commence a non-binding test phase of the SRI.

In order to enhance awareness of the advantages associated with smart buildings and to facilitate the implementation of the SRI framework at the EU and Member State levels, the EU LIFE Programme has provided support for a series of initiatives, including the SRI-ENACT project (12.2022 – 05.2025), which covers Austria, Bulgaria, Croatia, the Czech Republic, Greece, Latvia, Romania, and Spain. SRI-ENACT is coordinated by SingularLogic, with the Bulgarian partner being the Black Sea Energy Research Centre. The main project activities include the development of a web-based SRI Toolkit, the SRI assessment of 1,200 buildings across the EU (of which 130 are located in Bulgaria), and the co-creation of national SRI frameworks (policy, financing, etc.).

In April 2024, the Bulgarian Government notified the European Commission that it had initiated a non-binding test phase of SRI, based on the 130 SRI assessments conducted as part of the SRI-ENACT project.

Approach

In Bulgaria, the SRI assessments are conducted by 13 certified energy auditors who have additionally completed the SRI training course provided by SRI-ENACT. The audit results were verified by the SRI-ENACT team and, where necessary, updated in accordance with their feedback.

The assessments were made using the web-based SRI Toolkit.The toolkit is based on Regulation (EU) 2020/2155 on SRI Methodology and includes a catalogue of 54 prescribed smart technologies/services for the control of the nine Technical Building Systems (TBS), namely: heating, cooling, ventilation, hot water, lighting, dynamic building envelope, electricity, electrical vehicle charging, monitoring and control.

In order to simplify the process of data collection, only buildings possessing an EPB certificate were assessed in all of the project countries. These buildings exhibit a higher degree of “smartness” than the country average, due to the fact that the measures previously prescribed by EPB auditors are taken into account.

By mid-August 2024, a total of 44 buildings across almost all climatic subzones in Bulgaria had been assessed and their disaggregation by functional type is shown in Figure 1.

Figure 1. SRI assessed buildings by type in Bulgaria by mid-August 2024

Interim findings and lessons learnt from the SRI assessments in Bulgaria

In order to ensure the representativeness of the interim findings, the functional groups of buildings lacking data and those comprising fewer than four buildings have been excluded from the subsequent analyses.

Figure 2 depicts the average SRI score of the buildings in Bulgaria in comparison to the scores of buildings in the other countries, as assessed with the SRI-ENACT toolkit.

Figure 2. Comparison of the average SRI per country, based on the SRI-ENACT toolkit statistics by mid-August 2024 (in brackets is the number of buildings assessed)

The average SRI for Bulgaria is approximately 33%, which is the highest among all countries.

Figure 3 illustrates the average SRI score for each functional type of building.

Figure 3. Average SRI of 40 assessed buildings by type in Bulgaria, mid-August 2024

The relatively high average SRI level is largely attributable to the utilisation of renewable energy sources in the buildings sector. In Bulgaria, due to the availability of incentives, EPB auditors often prescribe measures such as PV systems with inverters that transmit control and monitoring signals from the grid, electric vehicle charging stations, high-efficiency heat pump systems for heating, cooling, ventilation and hot water, and, in some cases, the integration of existing building technical systems’ monitoring and control into a single building automation and control system (BACS)/building management system (BMS), etc.

Conversely, the SRI-ENACT interim results in Bulgaria provide insight into the "grey" areas in the existing legal and regulatory framework, as well as on the capabilities and practices of the EPB auditors, namely:

·         The absence of specific legal and regulatory requirements and incentives for the application of intelligent technologies for management of technical building systems (TBS) in new and renovated buildings constitutes a substantial impediment to their adoption.

·         The Building Management System (BMS/BACS) is not yet a mandatory component of the measures prescribed in the energy efficiency audits, nor is it a standard feature of investment projects for new and renovated buildings.

·         Technical building systems (TBS), such as electric vehicle (EV) chargers, dynamic building envelope and building automatic control systems, which operate with signals from external or local power grids, are also not legally binding parts of TBS and are therefore absent in the majority of buildings

·         It has hitherto been the practice of EPB auditors in the buildings sector to specify energy efficiency (EE) measures in the following manner:

o   The heat and/or the cold sources are evaluated based on a single technical criterion, namely the energy performance during the winter and/or summer seasons. Requirements for the functional level of management of the energy source for heating/cooling supply are not specified.

o   Buildings’ heat transmission and distribution systems – the specifications for pumps and fans are limited to capacity, without requirements for integrated flexible management that can adapt to the changing demands of heating, cooling and hot water.

·         The EPB auditors are unable to obtain the requisite feedback concerning the implementation of the prescribed EE measures, as well as the levels of functional perfection of the installed TBS and their potential integration into a building system for intelligent monitoring and control.

·         In the present circumstances, it would be advisable, the SRI auditors to collect data on the spot when as-built documentation is available for renovated buildings. Nevertheless, in the absence of such information, the time required for inspection may be significantly extended.

·         In the majority of investment projects, the chapter Automation and control or BMS/BACS is not assigned.

·         It would be appropriate to introduce regulatory minimum SRI levels for new and renovated non-residential buildings.

·         In light of the interdisciplinary nature of the concept of a 'smart' building, it is evident that the detailed catalogue of 54 intelligent control technologies for TBS management, the wireless data transfer, and the remote TBS control should be the subject of specific training for professional EPB auditors, MEP design engineers, facility managers, building owners, and all other users of the SRI-ENACT toolkit.

·         The online SRI-ENACT Toolkit has been met with considerable acceptance by SRI auditors and other users.

·         It is not always the case that a building with high energy efficiency class (nZEB, A) will have a high SRI. This is, because the TBS are not always built-up or set-up for intelligent operation, and the methodology for SRI evaluation also considers the needs of the building’s users and the power grid.

Typical examples

(1) New office building in operation from 2019 exhibits both a high SRI and a considerable potential for further improvement (Figure 4).

(2) Renovated office building with a low SRI and potential for its improvement (Figure 5).

Figure 4. The Office Buildng-2 Garitage Park, Sofia, Bulgaria. BREEAM certified; four similar buildings integrated in one BMS/BACS. SRI 57.1%

Figure 5. Office building, Vidin, Bulgaria. Good levels of EE for heating and cooling, PV system, but low levels of control and monitoring. SRI 16.6%

Next steps

Upon the conclusion and outcomes of the SRI assessment of a total of 1,200 pilot buildings in eight European countries, SRI-ENACT would reveal the regulatory and procedural possibilities for integrating this new assessment into the existing practices for EPB audits. Moreover, the successful completion of the large-scale pilot assessments will provide evidence of the effective implementation of SRI, thus enabling the creation of tailored national practices and financing schemes for SRI improvement. Furthermore, it will deliver policy and regulatory recommendations for the replication and wider uptake of the SRI-ENACT project tools and outcomes.