ALDREN: A Methodological Framework to Support Decision-Making and Investments in Deep Energy Renovation of Non-Residential Buildings

: Since 2002, the Energy Performance of Buildings Directive (EPBD) has set up the path to improve the efﬁciency gains in the EU building sector, including measures that should accelerate the rate of building renovation towards more energy efﬁcient systems. Under the 2010 EPBD, all EU countries have established independent energy performance certiﬁcation systems supported by independent mechanisms of control and veriﬁcation. The EU directive 2018/844 has introduced different novelties and one of these regards the possibility for the Member States, together with the Long-Term Renovation Strategies (LTRS), to introduce an optional Building Renovation Passport Article 2a.1(c), considered as an empowering document that gives more reliable and independent information on the potential for energy savings that is tied up in their buildings. On 14 October 2020, the European Commission launched its Communication and Strategy on the Renovation Wave initiative, intending to double the current Europe’s renovation rate to make the continent carbon neutral by 2050. However, current practices and tools of energy performance assessment and certiﬁcation applied across Europe face several challenges. In this context, the ALDREN project is a methodological framework that aims to support decision-making and investment in deep energy renovation of nonresidential buildings, based on a set of procedures (modules) that consist in the step-by-step implementation of protocols to assess the energy performance, indoor environmental quality, and ﬁnancial value of buildings, before and after the energy renovation. The paper presents the ALDREN overall procedure with a focus on the development of the Building Renovation Passport and its application to an Italian ofﬁce building.


Introduction
Over 3 years ago, a consortium of partners across seven EU countries came together to complete a proposal to the Horizon 2020 research programme, Energy Efficiency call EE- . The objective of this research was overcoming the regulatory and nonregulatory barriers to facilitate the renovation of existing building stocks. In this context, the ALliance for Deep RENovation in buildings (ALDREN) project started in November 2017. The project was led by the French scientific and technical center for building (CSTB) with a consortium of 8 partners: Politecnico di Milano, Danish Technical University, CERTIVEA, REHVA, Instituto Valenciano de la Edification, ENBEE, and VERCO [1].
The ALDREN project aims at implementing the European Common Voluntary Certification Scheme as backbone along the whole deep renovation process. The ALDREN procedure allows achieving higher renovation rates and better renovation quality by overcoming market barriers and preparing the ground for investments.

ALDREN Project: Framework and Tools
The main goal of ALDREN is to encourage investments and accelerate the movement towards a nearly Zero Energy nonresidential building stock across the EU, as targeted by 2050 to meet the Paris Agreement commitments [10]. To reach the European energy and climate objectives, the refurbishment of existing building stocks towards the deep renovation and NZEB levels is to be dramatically accelerated, in terms of both quantity (annual renovation rate) and quality (energy performance and overall quality).
A state-of-the-art review of the barriers for building renovation has revealed a lack of methodologies, which can promote sustainability objectives and assist various stakeholders during the design stage of building renovation/retrofitting projects. To this end, Decision Support System (DSS) or Multicriteria decision-making (MCDM) may help in evaluating and comparing different combined renovation scenarios, thus, promoting the regeneration of the building stock solving multiple-criteria decision problems. MCDM has become popular in energy planning as it enables the decision maker to pay attention to all the criteria available and make the appropriate decision as per the priority of the criteria.
In the latest years, a large spectrum of refurbishment tools and methods has been developed. Gohardani and Björk [11] present a valuable selection of those, highlighting that most of them only address a limited number of refurbishment criteria and they are valid for specific climatic contexts or local energy regulations. A multinational refurbishment, for example, should be considered, in order to capture the major disparities between the nations and to allow comparison and assessment. Besides that, different system approaches have also been developed for the analysis and problem solving in complex situations for sustainable renovations. Checkland and Scholes [12] distinguish between 'hard' and 'soft' systems thinking within the attempt to use system concepts to solve problems. Kamari et al. [13] provide a comprehensive overview on the refurbishment methods, which clearly highlights that developing a new sustainability decision-making support framework in a retrofitting context, is ultimately a very complex (due to different decision maker) and multidisciplinary task (within a sustainable perspective). Kamari, Jensen, Corrao, and Kirkegaard [14] investigated deeply MCDM design methodologies and processes for the building renovation field, and they identified a need for introducing three different decision-making levels to help stakeholders in the renovation process discuss their project "on the same level" and make transparent decisions in a rational order. Furthermore, the same authors introduced three sustainable retrofitting frameworks based on: (1)  Multimethodology for Sustainable Building Renovation (HMSR), to help stakeholders overcome the problem formulated above [15].
In this context, ALDREN's overarching goal is, therefore, to raise confidence in deep energy renovation, answering the needs of key stakeholder groups involved in the renovation implementation chain.
An ALDREN Alliance has been set up to better specify their needs and include them in high quality protocols. Interactions between the ALDREN Consortium and the ALDREN Alliance have also allowed raising awareness on the co-benefits related to deep energy renovation and to the use of harmonized, reliable, and transparent European performance ratings and reporting tools. For this reason, the NZEB has been considered as the main target of ALDREN renovation strategies. The Commission Recommendation (EU) 2016/1318 [16] on guidelines for the promotion of nearly zero-energy buildings [17] has been taken as the main reference for nearly zero office buildings and recommended values for hotel NZEB were the basis for hotel NZEB definition [18].
After the official conclusion of the project (29 September 2020) [19], ALDREN reached the goal to become a modular and a flexible methodological framework based on a set of procedures (modules) that consist in implementing step-by-step operational protocols to assess the energy performance, Indoor Environmental Quality (IEQ, related to health and well-being) and financial value of buildings, before and after the energy renovation. ALDREN protocols rely on simulations and measurements based on best practices and the consistent use of CEN and ISO standards to ensure transparency and quality. AL-DREN standalone modules produce a set of indicators that form consistent and holistic sustainability metrics. Alongside additional information, the indicators are reported in two dedicated and complimentary reporting tools that directly support the EU policies through the implementation of measures defined in the EPBD: The ALDREN European Voluntary Certification (EVC) and the ALDREN Building Renovation Passport (BRP).

The ALDREN EVC
The European Voluntary Certification Scheme (EVCS) has been introduced in Article 11 (9) of the EPBD [20], and within the ALDREN project it is a backbone that supports the implementation of a common EVCS for nonresidential buildings based on CEN-ISO standards. The ALDREN EVC and EVC+ (extended version of the first), developed within the project, can be considered as a snapshot of the building performance, quality, and renovation potential at a given time. It has been created as a common content and template of European certificate, reporting all indicators together with the recommendations for improvement of energy performance towards the NZEB, with the link to more detailed ALDREN Building Renovation Passport (BRP). It is a valuable instrument fully compliant with the requirements on energy performance certificates in EPBD, which provides a sustainability metrics that could be used as eligibility criteria to mobilize private and public investments on deep renovation for existing buildings.

The ALDREN BRP
The ALDREN Building Renovation Passport is a complementary tool to the ALDREN EVC and EVC+, which provides, besides the general recommendations of EVC, a more detailed description of renovation activities in terms of time, costs, and technical performance.
Its dynamicity allows updating the BRP over the time along the renovation path. Principles, target, and users of the ALDREN BRP are synthetized and described in Table 1, clarifying for each of these three points their respective success factors.
The ALDREN BRP has been developed as a complementary tool to the Energy Performance Certificate (EPC), with the aim to increase owners' awareness about the current technical energy performance status of their building, as well as support them for its regular daily operation, coupled with a tailor made renovation roadmap that provides an assessment of three main Key Performance Indicators (KPIs):
Investment costs of ALDREN renovation actions to reach KPI n.1 (€ and €/m 2 ) Harmonized procedure for building data gathering through the time, with a common language in a cost-effective renovation plan.

BUILDING TYPOLOGY ENERGY TARGET
Data sets for nonresidential buildings (hotels/offices). BRP structure suitable also for residential: BuildLog + RenoMap, with different detailed indicators in function of building typology and owner needs.
Follow the ALDREN protocols steps for BRP creation. Collect users will and use it for the RenoMap creation.

OWNER/INVESTOR (O) ALDREN AUDITOR (AA)
Refer to a unique instrument. Comprehension of real current state of the building.
Awareness on the renovation actions feasibility.
Refer to the ALDREN protocols guidance for the BRP creation based on step-by-step procedure. Collect users will for the RenoMap creation.
One of the main important added values reached by the ALDREN BRP is the possibility to have two different versions of it, digital and paper, which facilitate the data comprehension by different possible users. The digital version includes all the data collected and calculated for the BRP procedure application, while the paper one is a portable version to increase the understanding of the core indicator values of the building by the majority of the BRP users regardless of their knowledge background in construction.
The creation of the ALDREN BRP follows a step-by-step procedure, as listed in Table 2. The five main steps are divided into subactivities in which is evident the importance given to the relationship between the owner and the ALDREN auditor. Table 2.
Step-by-step procedure for the ALDREN Building Renovation Passport (BRP). Step

2.2
Collection of all documentation (digital, paper version) from different sources (i.e., existing database or O).

2.3
Population of the selected BuildLog modules with inputs collected for the calculation of the protocols. The main remark to be highlighted in this phase is the nonmandatory fulfillment and compilation of all the modules of the Building Logbook (BuildLog), since the selection depends on the owner's needs, will, and investment.

The ALDREN BRP Structure
The ALDREN BRP refers to travel passport analogy. Thus, the renovation path is considered as a journey on which the travelers (in this case owners or investors) are the main actors deciding the "stops" along the trip according to their will, financial availability, or other boundary conditions. The building owners and investors can choose which renovation actions to take, as well as when, how, and in which order the actions are carried out. The stamps of Figure 1 represent the Renovation "stop" in the travel analogy, which correspond also to the structure modules of the ALDREN BRP. The main remark to be highlighted in this phase is the nonmandatory fulfillment and compilation of all the modules of the Building Logbook (BuildLog), since the selection depends on the owner's needs, will, and investment.

The ALDREN BRP Structure
The ALDREN BRP refers to travel passport analogy. Thus, the renovation path is considered as a journey on which the travelers (in this case owners or investors) are the main actors deciding the "stops" along the trip according to their will, financial availability, or other boundary conditions. The building owners and investors can choose which renovation actions to take, as well as when, how, and in which order the actions are carried out. The stamps of Figure 1 represent the Renovation "stop" in the travel analogy, which correspond also to the structure modules of the ALDREN BRP. The core structure of the passport foresees two main elements: Building Logbook (ALDREN BuildLog) and a tailored Renovation Roadmap (ALDREN RenoMap). The BuildLog informs building owners and managers about the current condition of the building in terms of its technical energy, indoor environmental quality (IEQ), and financial performance status. The RenoMap provides medium-and long-term renovation strategies to reach NZEB target to avoid lock-in effects.
Flexibility and modularity are the main important characteristics of the ALDREN BRP structure. The 8 BRP modules (corresponding to the 8 stamps, as shown in Figure 1) are connected but can be filled independently by an ALDREN auditor according to the renovation requests of the building owners. The digital version of the BRP is an Excel file The core structure of the passport foresees two main elements: Building Logbook (AL-DREN BuildLog) and a tailored Renovation Roadmap (ALDREN RenoMap). The BuildLog informs building owners and managers about the current condition of the building in terms of its technical energy, indoor environmental quality (IEQ), and financial performance status. The RenoMap provides medium-and long-term renovation strategies to reach NZEB target to avoid lock-in effects.
Flexibility and modularity are the main important characteristics of the ALDREN BRP structure. The 8 BRP modules (corresponding to the 8 stamps, as shown in Figure 1) are connected but can be filled independently by an ALDREN auditor according to the renovation requests of the building owners. The digital version of the BRP is an Excel file composed by worksheets, which corresponds to the passport structure (6 sheets for the BuildLog modules and 2 for the RenoMap). In addition, there is the "read me" instruction sheet, which provides quick start guidance to the AA and the legend of the source compliancy of the indicators. Each module has an associated color corresponding to a specific source from which it has been selected or referred. The guidance allows the ALDREN auditor to understand the definition of the items in the modules and the method for calculating the standard values, depending on the reference.
At the end of the project, in order to support the dissemination and use of the ALDREN BRP, a dedicated training for each module has been developed under the BuildUp platform and available also in the project website [1].

ALDREN BuildLog
Data collection, management, and digitalization are core topics for the European Commission. In the latest Communication COM (2020), 662 final on the Renovation Wave [21], it is underlined the importance to introduce a Digital Building Logbooks that will integrate all building related data provided by the upcoming Building Renovation Passports, Smart Readiness Indicators [22], Level(s) [23], and EPCs to ensure compatibility and integration of data throughout the renovation journey.
The comparative analysis, conducted within the ALDREN project, on the in-place initiatives on logbooks highlighted that they are all still facing many barriers for a further implementation or harmonization, such as: Costs implications, privacy and data management, fragmented regional approaches, static nature of the building logbook, administrative burden, and access to information [24].
For those reasons, the final version of the ALDREN BuildLog consists of six different modules (Table 3) with specific subcategories and respective protocols (detailed information can be found in the respective references listed in Table 3) to follow the implementation. The modules are independent from one another while the data are shared among them to optimize the information collection process. The BuildLog could facilitate access to structured information about how the building was originally designed, what changes have been made, and what its actual performance service level and planned maintenance is [25]. Outlines the current state of the building in terms of geometry, location, documentation, certification, technical components, and general information on ownership. ALDREN auditor collects the main information without performing any calculation. Some of the indicators collected will automatically be used in other modules. the value of each indicator refers to the eventual availability of documentation; in positive case, it should be clarified in which format (digital, paper, or other) the indicator is available, eventually specifying the name and repository.
The ALDREN BuildLog can accompany the building manager and/or owner to collect the necessary building data, to have the information on the building's current state. This information is used to evaluate the possible renovation actions to be carried out on the building to reach the NZEB target. The main reference for a harmonized ALDREN NZEB definition at EU level is the Commission Recommendation EU 2016/1318 on guidelines for the promotion of nearly zero-energy buildings [16].

ALDREN RenoMap
As foreseen by the EPBD [20], Building Renovation Passports provides a roadmap for staged renovation over the lifetime of a building, helping owners and investors plan the best timing and scope for interventions. The ALDREN RenoMap aims to be the instrument that can support the ALDREN auditor and the building owner to identify (1) the potential Elementary Renovation Actions (ERAs) to be applied based on the current building conditions and the owner will, and (2) the timeline to follow and the respective costs with the final aim to reach a high/NZEB-compliant performance level. The RenoMap section of the ALDREN BRP is structured into two different modules (Table 4).

N.
Module Name Description

M7 Elementary renovation actions
Identification and definition of a set of Elementary Renovation Actions (ERAs) related to the building specificities and actual potential in order to reach a high/NZEB-compliant performance level. The ALDREN Auditor has to identify the jump from the existing state to the renovated one (defined by levels from 0 to 4).

M8
NZEB roadmap Design of a structured roadmap to support the decision-making process, defining the final timeline that summarizes the periods of renovation action implementation, including both the evaluated primary packages and the remaining ERAs. A first graph (on the bottom left in Figure 2) shows the temporal evolution of the building energy performance until 2050, from the initial stage to the fully renovated stage following the upcoming renovation actions. The energy-performance labels associated with the different building stages are calculated, respectively (second graph on the bottom right in Figure 2). There are three main outcomes of the RenoMap application: 1. The identification of all the ERAs and the associated fully renovated building, which sets a final long-term objective and informs on the potential energy savings; 2. The primary packages evaluation, which provides guidance to the upcoming renovation and supports the short-term decision; 3. The long-term step-by-step timeline, displaying the renovation path for the following years according to replacement periods and opportunities.   The summary depicts the assessment of the building at its initial state, after the intended renovation (current renovation project), and after the full potential renovation, respectively.
A first graph (on the bottom left in Figure 2) shows the temporal evolution of the building energy performance until 2050, from the initial stage to the fully renovated stage following the upcoming renovation actions. The energy-performance labels associated with the different building stages are calculated, respectively (second graph on the bottom right in Figure 2).
There are three main outcomes of the RenoMap application: 1.
The identification of all the ERAs and the associated fully renovated building, which sets a final long-term objective and informs on the potential energy savings; 2.
The primary packages evaluation, which provides guidance to the upcoming renovation and supports the short-term decision; 3.
The long-term step-by-step timeline, displaying the renovation path for the following years according to replacement periods and opportunities. Table 5 summarizes the main tasks of the RenoMap method. Building LOGBOOK Evaluation Table of  ERAs Step-by-step roadmap v0 Step-by-step roadmap v1 6 Processing of renovation strategy Mandatory Identification of primary renovation actions according to obsolescence level, owner will, energy efficiency, and other indicators. Constitution of packages with interacting ERAs.

Strategy guidance
Step-by-step roadmap v2 Step-by-step roadmap v3 Step-by-step roadmap v4 9 Results report for decision support

Mandatory
Choice of the final renovation configuration. Display of outcomes. Viewing on the labels and timeline curves.
Step-by-step roadmap v4 Step-by-step roadmap consolidated version

The ALDREN BRP Application: An Italian Office Pilot Case
The ALDREN BRP procedure was applied to an Italian office building (the pilot case study). The renovation results for the modules selected by the building owner are presented in the following section.

Building Description
The Italian ALDREN pilot is an office building within the Lecco Campus of the Politecnico di Milano university, a few steps from the center of Lecco within the recovered and upgraded area of the former public hospital of the city, in via Ghislanzoni (Figure 3). ERAs. Filling in labels curve on the template of the final renovation roadmap.
Step-by-step roadmap v0 6 Processing of renovation strategy Mandatory Identification of primary renovation actions according to obsolescence level, owner will, energy efficiency, and other indicators. Constitution of packages with interacting ERAs.

Strategy guidance
Step Step-by-step roadmap v3 Step-by-step roadmap v4 9 Results report for decision support

Mandatory
Choice of the final renovation configuration. Display of outcomes. Viewing on the labels and timeline curves.
Step-by-step roadmap v4 Step-by-step roadmap consolidated version

The ALDREN BRP Application: An Italian Office Pilot Case
The ALDREN BRP procedure was applied to an Italian office building (the pilot case study). The renovation results for the modules selected by the building owner are presented in the following section.

Building Description
The Italian ALDREN pilot is an office building within the Lecco Campus of the Politecnico di Milano university, a few steps from the center of Lecco within the recovered and upgraded area of the former public hospital of the city, in via Ghislanzoni (Figure 3). The group of buildings was built in 1990 to form a comb shape. The studied building has two floors above the ground level, and the windows mark a regular rhythm in the façade. An intense refurbishment intervention of the building was carried out in 2014, The group of buildings was built in 1990 to form a comb shape. The studied building has two floors above the ground level, and the windows mark a regular rhythm in the façade. An intense refurbishment intervention of the building was carried out in 2014, which preserved the main structure, improved the envelope performance, upgraded the internal space distribution to fulfill the new functions, and integrated renewable energy sources to reduce its energy consumptions. In addition to the refurbishment intervention that has been put in place, the building was studied in the ALDREN project due to the interest of the building owners on developing its RenoMap to identify the necessary renovation actions to reach the NZEB target. The following tables provide a summary of the building's key features, in terms of construction technologies and system strategies ( Table 6), and boundary climatic conditions (Table 7). According to these data, the nearest Typical Meteorological Year (TMY) for the hourly energy calculation was selected.

Uses layout
Offices: Administration, university offices and meeting rooms.

Envelope
Walls with 70-100 mm layer of polystyrene fiber insulation. Curtain walls made of aluminum profiles with uprights and crossbeams. Internal motorized shading system with vertical sliding. Aluminum windows with thermal break.

Systems
AHU + VAV: All-air systems with partial recirculation Air Handling Units and systems with Variable Air Volume. FCAP: Air-water mixed systems with fancoil and primary air.
REX: Radiators and exhaust air system.

Application of the ALDREN Step-by-Step Approach
The application of the ALDREN BRP to the Italian office building followed the procedure described in Section 2 of the present paper, as outlined in particular in Table 2.

First Contact Interview
An initial meeting was held with the building owner to sign the agreement to apply the ALDREN protocol to the office building. On this occasion, as prescribed by subactivity #1.3, the ALDREN auditor and the owner selected the BRP modules to be successively calculated: M1; M2; M4; M6; M7; and M8.

Data Collection and ALDREN Database Creation
During the data collection step, the ALDREN auditor held different meetings with the facility management staff and the owner to check, revise, and organize all the technical documents necessary for the ALDREN protocol application.
For the measurements of the different indicators required for the M4 protocol, a monitoring campaign started in November 2019 for the duration of one month. It was difficult to collect data on the energy consumption per energy vector, since the plant systems covered the energy demand of more buildings with different functions altogether, and there was no submetering system that allows to derive the data for the single pilot case building.

ALDREN Protocols Calculation and Population of the Selected BuildLog Modules
The calculation software used to draft the energy modeling was TRNSYS 18 [36], a complete, modular, and expansible simulation environment for the transient simulation of thermal systems, including multizone buildings. The following steps were followed to process the data: (i) 3D modeling of the building and identification of thermal zones, (ii) setting of the characteristics related to the building, through the TRNBuild plug-in, (iii) processing and simulation of the data entered, by the use of Simulation Studio plug-in.
The entire model of the building is presented in Figure 4 and it was divided into eleven thermal zones for the calculations.

Data Collection and ALDREN Database Creation
During the data collection step, the ALDREN auditor held different meetings with the facility management staff and the owner to check, revise, and organize all the technical documents necessary for the ALDREN protocol application.
For the measurements of the different indicators required for the M4 protocol, a monitoring campaign started in November 2019 for the duration of one month. It was difficult to collect data on the energy consumption per energy vector, since the plant systems covered the energy demand of more buildings with different functions altogether, and there was no submetering system that allows to derive the data for the single pilot case building.

ALDREN Protocols Calculation and Population of the Selected BuildLog Modules
The calculation software used to draft the energy modeling was TRNSYS 18 [36], a complete, modular, and expansible simulation environment for the transient simulation of thermal systems, including multizone buildings. The following steps were followed to process the data: (i) 3D modeling of the building and identification of thermal zones, (ii) setting of the characteristics related to the building, through the TRNBuild plug-in, (iii) processing and simulation of the data entered, by the use of Simulation Studio plug-in.
The entire model of the building is presented in Figure 4 and it was divided into eleven thermal zones for the calculations. The envelope technologies used for the energy modeling of the office building are defined in Tables 8 and 9. The air tightness/infiltration rate (0.25 1/h) was obtained through on-site measurements.  The envelope technologies used for the energy modeling of the office building are defined in Tables 8 and 9. The air tightness/infiltration rate (0.25 1/h) was obtained through on-site measurements.

ALDREN RenoMap Definition
After the evaluation of the current state of the building in 2020, and considering the refurbishment made during the first renovation in 2014 from the original construction of 1900, the elementary renovation actions were identified with the main goal of improving the internal comfort and reaching the NZEB target, consequently reducing consumptions. All the packages of renovation actions identified were selected combining the owners' needs and the obsolescence level of the building. The packages identified within the RenoMap are summarized in Table 11.  Table 10 lists the general settings considered in the building energy model.

+4
Heat pump replacement Amelioration of PV system 2034-2040 High economy efficiency-potentially immediate

Results
The application of the selected modules (M1; M2; M4; M6; M7; and M8) led to the creation of the ALDREN BRP in both digital and paper versions. Since the results of Modules 2, 4, and 8 are presented in the dedicated following subsections of the present manuscript, for brevity, Figure 5 shows only the cover and the KPIs page of the ALDREN BRP paper version.

Results
The application of the selected modules (M1; M2; M4; M6; M7; and M8) led to the creation of the ALDREN BRP in both digital and paper versions. Since the results of Modules 2, 4, and 8 are presented in the dedicated following subsections of the present manuscript, for brevity, Figure 5 shows only the cover and the KPIs page of the ALDREN BRP paper version. In particular, for the sake of paper comprehension and brevity, the following subsections focus only on the presentation of the core indicators results related to energy (M2), well-being (M4), and renovation actions (M7-M8) to address the three main ALDREN Key Performance Indicators (KPIs).

Key Performance Indicators (KPIs)
The three ALDREN BRP KPIs were evaluated according the ALDREN RenoMap under standard conditions and are summarized in Table 12. In particular, for the sake of paper comprehension and brevity, the following subsections focus only on the presentation of the core indicators results related to energy (M2), well-being (M4), and renovation actions (M7-M8) to address the three main ALDREN Key Performance Indicators (KPIs).

Key Performance Indicators (KPIs)
The three ALDREN BRP KPIs were evaluated according the ALDREN RenoMap under standard conditions and are summarized in Table 12.
The RenoMap packages were identified according to the owners' needs and the obsolescence level of the building. The cost of the renovation actions according to the reference costs from construction companies and market values databases was calculated but was not considered as an impact factor for the study.

Energy Rating and Target (M2)
The application of the relative protocol calculations led to the results on the energy rating and target as represented in Figure 6. The RenoMap packages were identified according to the owners' needs and the ob solescence level of the building. The cost of the renovation actions according to the refer ence costs from construction companies and market values databases was calculated bu was not considered as an impact factor for the study.

Energy Rating and Target (M2)
The application of the relative protocol calculations led to the results on the energ rating and target as represented in Figure 6. The energy rating, according to the M2 protocol, is equal to class B for the buildin at the current state (corresponding to the "before renovation" in the graph above), an class A with the full ERAs packages application (corresponding to the "full potential ren ovation" in Figure 6).

Comfort and Well-being (M4)
The indoor environmental quality (IEQ) level of the building was assessed by th TAIL index according to the ALDREN-TAIL protocol [37][38][39]. The TAIL index evaluate the quality levels of four indoor environmental quality (IEQ) components, i.e., therma environment (T), acoustic environment (A), indoor air quality (I), and luminous environ ment (L), as well as the overall IEQ level of the building.
The TAIL index consists of 12 IEQ indicators, such as the air temperature, soun pressure level, formaldehyde concentration, and luminous level. The indicators were a assessed objectively by measurements. The results of the TAIL index for the Italian offic building are shown in Figure 7. The energy rating, according to the M2 protocol, is equal to class B for the building at the current state (corresponding to the "before renovation" in the graph above), and class A with the full ERAs packages application (corresponding to the "full potential renovation" in Figure 6).

Comfort and Well-being (M4)
The indoor environmental quality (IEQ) level of the building was assessed by the TAIL index according to the ALDREN-TAIL protocol [37][38][39]. The TAIL index evaluates the quality levels of four indoor environmental quality (IEQ) components, i.e., thermal environment (T), acoustic environment (A), indoor air quality (I), and luminous environment (L), as well as the overall IEQ level of the building.
The TAIL index consists of 12 IEQ indicators, such as the air temperature, sound pressure level, formaldehyde concentration, and luminous level. The indicators were all assessed objectively by measurements. The results of the TAIL index for the Italian office building are shown in Figure 7.
The TAIL results for the building "before renovation" were calculated following the TAIL protocol and referring to the measurement campaign and the IEQ level of the building at the current state. The TAIL results for the building "after renovation" refer to evaluations based on simulation analysis.

Elementary Renovation Actions (M7) and NZEB Roadmap (M8)
The NZEB RoadMap of the office building was structured from the Elementary Renovation Actions (ERAs) packages identified and listed in Table 12. Figure 8 represents the temporal evolution of the building energy performance until 2050, from the current stage to the fully renovated building after applying the renovation packages. The TAIL results for the building "before renovation" were calculated following the TAIL protocol and referring to the measurement campaign and the IEQ level of the building at the current state. The TAIL results for the building "after renovation" refer to evaluations based on simulation analysis.

Elementary Renovation Actions (M7) and NZEB Roadmap (M8)
The NZEB RoadMap of the office building was structured from the Elementary Renovation Actions (ERAs) packages identified and listed in Table 12. Figure 8 represents the temporal evolution of the building energy performance until 2050, from the current stage to the fully renovated building after applying the renovation packages.   The TAIL results for the building "before renovation" were calculated following the TAIL protocol and referring to the measurement campaign and the IEQ level of the building at the current state. The TAIL results for the building "after renovation" refer to evaluations based on simulation analysis.

Elementary Renovation Actions (M7) and NZEB Roadmap (M8)
The NZEB RoadMap of the office building was structured from the Elementary Renovation Actions (ERAs) packages identified and listed in Table 12. Figure 8 represents the temporal evolution of the building energy performance until 2050, from the current stage to the fully renovated building after applying the renovation packages. Step-by-step roadmap result for Building 8, Politecnico di Milano-Lecco Campus. Figure 8. Step-by-step roadmap result for Building 8, Politecnico di Milano-Lecco Campus.

Conclusions
The research contributions of ALDREN protocol in comparison to the existing one for sustainable renovations of nonresidential buildings are: (i) the development of an overall methodological framework consisting of four standalone modules to assess the energy performance, Indoor Environmental Quality, and financial value of buildings with two reporting tools (EU Voluntary Certificate, Building Renovation Passport); (ii) the introduction of a specific index, called ALDREN-TAIL, to rate the Indoor Environment Quality (IEQ) of buildings before and after renovation, focusing on four key components: Thermal environment (T), Acoustic environment (A), Indoor air quality (I), Luminous environment (L), and (iii) the development of a "Performance Verification Tool" (PVT) to compare predicted and actual performance at different levels of granularity.
Referring then to the ALDREN BRP development and application to some real cases and, in particular, to the one presented in this paper, some weaknesses and strengths are listed as follows, to identify open issues and points that may be implemented in future studies.

•
The implementation and use of the ALDREN BRP can support the reduction of administrative burden for owners and professionals and avoid the lock-in effect reducing the information asymmetries, but it needs a common language and a central European repository for reliable data on the building stock, its energy performance, and available financial incentives.

•
The ALDREN BuildLog is a first trial of the Digitalized Building Logbook that could be adapted to other building typologies to cover the needs of the EU building stock.

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The ALDREN RenoMap identifies more realistic operation and maintenance renovation actions compared to the current EPC recommendations, but its development requires a specific background and training preparation in order to fulfill the evaluation according to the ALDREN protocols.
Although the work presented in this paper is informed by the partial application of the ALDREN framework and some parts of the methodology are still incomplete, we accept that its development is in line with the renovation wave initiative in scope and we hope it can contribute to building passport and certification tools development more comparable and harmonized across the EU.
Further development of the framework will include more explicit examination and application of some economics and IEQ indicators, which could be calculated thanks to simulation to improve the renovation packages' evaluation process. According to the organization of the RenoMap process, Excel is probably not the most suitable and efficient tool. For a wider development, a more web-based application may be needed to make calculations automated.  Data Availability Statement: Publicly available datasets were analyzed in this study. This data can be found here: https://aldren.eu/project/polimi/.