Acta Polytechnica CTU Proceedings https://doi.org/10.14311/APP.2022.38.0436 Acta Polytechnica CTU Proceedings 38:436–442, 2022 © 2022 The Author(s). Licensed under a CC-BY 4.0 licence Published by the Czech Technical University in Prague ADAPTING FAÇADE PERFORMANCES TO CLIMATE CHANGE IN NORTHERN EUROPE: ANALYSIS OF FUTURE SCENARIOS FOR AN OFFICE BUILDING IN STOCKHOLM Matteo Costanzoa,∗, Andrea Giovanni Maininib, Giuliana Iannacconeb, Ivo Martinacc, David Parsmand a WSP in the UK, Facade Department, 70 Chancery Lane, WC2A 1AF London, UK b Politecnico di Milano, Architecture Built Environment Construction Engineering Department, 20133 Milano, Italy c KTH Royal Institute of Technology, Building Services and Energy Systems Department, 11428 Stockholm, Sweden d WSP Sverige, HVAC and Energy System Departement, 7 Arenavägen, 12188 Stockholm, Sweden ∗ corresponding author: matteo.costanzo1995@gmail.com Abstract. Future climate change will affect many human activities and sectors. Among those, the built environment will face several challenges about the varying climate conditions, including increased demand for summer cooling and related heat stress indoor conditions. In this framework, the paper presents the results of a recent study that investigated the global warming impacts on energy demand and indoor climate comfort for an office building in Stockholm over the next 50–60 years. The future climate conditions were investigated in 2070 and 2080 with different climate morphing approaches. Three different passive cooling solutions to decrease the cooling demand (such as external roller shade, electrochromic glazing, and internally ventilated shading) have been preliminarily assessed about thermal and optical properties, then integrated into the building energy simulation software IDA-ICE to evaluate the building energy performances regarding different Swedish climates, and finally economically estimated with a simplified LCC analysis. The results indicated that an increment of the cooling demand from 3 up to 24 kWh/m2 and a reduction of the heating usage of 20–50 % will be experienced in 50–60 years. The different weather data morphing approaches displayed the inherent uncertainties when future evaluations are performed, although similar weather patterns were found. The improvement of the solar and optical properties indicated a lower cooling and ventilation usage with reductions of about 10–16 %. The electrochromic technology reported the lowest cooling demand (decrease up to 24 %), while the internally ventilated shading option outperformed the others with an annual energy consumption 4–9 % lower and the lowest LCC. Keywords: Climate change, building design, passive cooling solutions, solar control techniques. 1. Introduction World population is constantly increasing, and with it also its needs, consumptions, and emissions. In the European Union (EU), research and analyses about energy consumption and greenhouse gases (GHGs) emissions reported how the built environment was re- sponsible in 2018 for approximately 40 % of the energy consumption and 36 % of all the CO2 emissions in the EU countries [1]. In Sweden, the building and services sector represents the predominant one, accounting for more than 34 % of the overall energy usage [2]. Buildings are usually designed and constructed to pro- vide a service life of 50 years, consequently raising the importance of a detailed preliminary study in the building design process to assess its behaviour and response to possible different climatic conditions. The expected air temperature increase will soon promote space cooling as one of the major challenges in the building sector [3], thus design solutions that can de- crease the cooling demand of the buildings will come to be of crucial value. Among those, passive cooling strategies, which take advantage of natural and renew- able resources to reduce the building energy usage, can be a vital contribution. Nowadays the fast progress of a worldwide climate change is evident with several environmental alter- ations. The Intergovernmental Panel on Climate Change (IPCC) reported the risks of profound changes in the Earth system given by the increase in GHGs emissions [4]. The global rise of average temperature is the foremost and most detectable aspect, with a measured warming of 0.85 °C over the period 1880– 2012 [5]. This increase is mainly connected to the increase in CO2 emissions and the related greenhouse effect, directly connected to both human activities and natural causes [6]. The construction sector in Sweden is regulated by the Swedish Board of Housing, Building and Planning (Boverket), which determines the constrains in terms of energy demand and indications for the indoor com- 436 https://doi.org/10.14311/APP.2022.38.0436 https://creativecommons.org/licenses/by/4.0/ https://www.cvut.cz/en vol. 38/2022 Adapting façade performances to climate change in Northern Europe . . . Figure 1. Typical floor layout. fort together with other national and international authorities. In this research, the building code Bover- kets Byggregler (Boverket’s building rules – BBR) with modification up to BFS 2019:2 (“BBR 28”) was taken into consideration for the energy performances evaluation of the case study [7]. Considering an office building, the energy performance (expressed as pri- mary energy) is limited to 80 kWh/m2Atemp, and the envelope performance (considered as Um-value, average heat transfer coefficient) is limited to 0.60 W/m2K. For what concerns the indoor comfort, specific rec- ommendations for thermal comfort in office buildings and workplaces are reported by the Swedish Work En- vironment Authority (SWEA) based on the provisions given by the EN 7730 [8]. The indoor operative tem- perature ranges are 20–24 °C in winter and 20–26 °C in summer, for an office building. Finally, indoor vi- sual comfort is restricted directly by Boverket which takes into considerations a minimum level of Daylight Factor (DF) of 1 % for rooms with direct access to sunlight in office buildings [7]. In cooling-dominated buildings external shading devices are efficient tools to block the direct and part of the diffuse solar radiation. According to Kunwar et al. [9], the introduction of external roller shades enables an increase in energy savings, with a cooling demand decrease up to 26 %. While an in-situ study carried out by Ip et al. [10] showed an annual energy demand reduction of 16 % and a maximum reduction of the air temperature of 3.5 °C when external roller shades have been implemented instead of internal venetian blinds into an office building in Brighton (U.K.). Cannavale et al. [11] recently analysed different kinds of electrochromic (EC) glazing for a medium- sized office building, obtaining a reduction of the annual energy demand up to 23 % and a cooling usage reduction of 60 %. Ajaji & André [12] reported en- hancements of the indoor thermal and visual comfort performances for an office space, limiting the indoor temperature and the risk for over-illumination. In the case of internal shading systems, which are known to be less performing, a promising solution cou- ples the system with an exhaust air extraction system to remove the stored heat before it is re-irradiated into the room. Denz et al. [13] considered in their study a similar integration in the gap between window and SD. In this research, the g-value of the system has been reduced by 50 % with a cooling energy demand decrease of 25 %. Similarly, Gustafsson & Säfblad [14] evaluated an internally ventilated system, variating several parameters, such as gap width, shading’s fab- ric, and air flow rate, obtaining a g-value reduction up to 45 %. 2. Methodology 2.1. Stockholm Case Study The selected case study is a typical modern 10-storey office building, with the two main façades facing north and south. The building is located in the central urban area of Stockholm city (Sweden) and fulfils the latest building regulations and construction standards. The total floor area is 430 m2, with 57 occupants per floor, divided between single offices (10 m2), meeting rooms (26–28 m2) and an open space of 115 m2. The floor height is 2.6 m and the windows have dimensions 1.1 × 2.2 m and 2.2 × 2.2 m, for a total WWR of 23.3 %. A schematic representation of the typical floor is reported below in Figure 1. The parameters of the case study model are set into the IDA-ICE software to represent a typical of- fice usage, in accordance with the prescriptions of the Swedish building code (BBR 28). Among those, gen- eral construction parameters, internal gains settings, and the AHU system are defined also according to the Swedish Building Environmental Certification System “Miljöbyggnad” [15] and the Sveby (Standardize and Verify Energy Performance in Buildings) “User data for Office” [16], when not specified by the building code. Afterwards, in order to analyse the IDA-ICE re- sults, the energy consumption is divided into electric, district, and tenancy demand, as required by Swedish building regulations. The purchased energy is multi- plied by the Primary energy factor per energy carrier (PE), except the consumption due to the tenancy use, 437 M. Costanzo, A. G. Mainini, G. Iannaccone et al. Acta Polytechnica CTU Proceedings Glazing Units Screen properties G1 G2 G3 S1 S2 Clear Int. 1∗ Int. 2∗∗ Tinted Tvis 70 % 63 % 21 % 6 % 2 % 60 % Tvis 22 % 4 % Rfext 11 % 11 % 6 % 5 % 5 % 14 % Tsol 24 % 4 % Rbint 13 % 12 % 10 % 9 % 10 % 17 % Rsol 39 % 74 % g-value 0.31 0.47 0.16 0.09 0.06 0.27 O.F. 14 % 2 % U-value [W/m2K] 1.0 1.4 1.4 1.4 1.4 1.0 Emisfront 76 % 19 % Emisback 76 % 81 % ∗ Int. 1 = Intermediate state 1. ∗∗ Int. 2 = Intermediate state 2. Table 1. Solar control glasses performances and Screen fabric properties. and the energy demand for the electric cooling is fur- ther increased by the electric cooling factor (1.875) in accordance with section 9:2 of BBR 28, which must be considered in buildings with an installed electric input for space heating and hot tap water below 10 W/m2. 2.2. Solar Control Techniques Evaluation In this paper, the performances of triple glazed units with different solar and light properties and under different shading conditions were assessed. The shad- ing strategies consist in an external vertical awning with a roller blind (G1), electrochromic properties (G2), and an interior reflective fabric screen fabric with a ventilated air gap (G3). The external and internally ventilated shading techniques are charac- terized by a high selectivity solar control glass pane and a low-E pane, respectively on the outer and inner glass panes. The shading devices used are a roller screen made of a composite fabric in a vinyl-coated polyester mesh for the outdoor use (S1), and a semi- transparent metallised roller screen with a higher solar reflection and lower emissivity for the indoor case (S2). The electrochromic solution has a dynamic glass pane instead of the high selectivity one. The optical and thermal properties of the insulated glass units and the screen fabric characteristics are reported in the following Table 1. The overall optical and thermal properties of the different solutions are determined following the calcu- lation methods provided by the European standards in matter of glazing and energy calculation for buildings ([17–19]). The calculations are carried out with the support of the software LBNL Window 7.7 [20]. Case G3 requires the assessment of the thermal and opti- cal performances of the glazing-shading system when the exhaust air extraction is active. WIS tool [21] is used assess the optimal ventilation rate and the rela- tive thermal and optical performances of the system. A preliminary energy balance of a room is provided in accordance with the European standard EN ISO 52016-1:2017 [22]. The energy balance for the most critical hour of a winter, summer, and midseason day is analysed for an office room with an airflow varying from 0.18 m3/h to 5.4 m3/h, in accordance with the results derived from the literature review ([13, 14]). Then, the passive cooling solutions performances are subsequently introduced into the IDA-ICE model building performance simulation software, version beta 07, to assess the building energy consumption and the indoor thermal comfort for the office building under investigation [23]. 2.3. Climate Scenarios The climate conditions investigated in this paper con- sist of the current climate of Sweden and two cli- mate scenarios for the future conditions which con- sist of hourly data of temperature, relative humid- ity, wind speed and direction, and solar radiation. The current climate conditions (C1) are provided by the Swedish Meteorological and Hydrological Insti- tute (SMHI) for city of Stockholm [24]. The future climate scenarios are based on the emission models provided by the IPCC, called “Representative Con- centrations Pathways” (RCPs) [5]. The first future climate scenario (F1) was derived from a previous work by Tsaousoglou [25] for the year 2070 and RCP4.5, only considering the variation of the air temperature. The latter was initially increased by 5 °C in winter and 2 °C in summer with a linear variation in the transition months, and then manually modified with increased temperature up to 31.2 °C, to include varia- tions in the amount of tropical nights and heatwaves periods [26]. The second future climate scenario (F2) was alternatively derived from the baseline climate data by EnergyPlus weather database for the location Stockholm-Arlanda [27]. The climate morphing was carried out with the support of the Climate Change World Weather Generator [28]. The climate scenario refers to the year 2080 and the forecasted scenario denoted as B1 [29], which projects the comparable amount of CO2 emissions and reflects similar changes in the weather parameters by the year 2100 as for the RCP4.5 previously selected [4], due to limitations of the climate generator tool. In Figure 2 is shown the monthly average daily temperature in Stockholm for the three climate scenarios under analysis. 438 vol. 38/2022 Adapting façade performances to climate change in Northern Europe . . . Figure 2. Monthly average daily temperature in Stockholm for the three climate scenarios. Figure 3. Graphical report of the g-value results with respect to the extraction airflow rate. Element U.M. G1 + S1 G2 G3 + S2 Window SEK/m2 3500 8500 3500 Shading SEK/m2 3000 - 1100 Extraction SEK/m2 - - 977.1 Total SEK/m2 6500 8500 5577.1 Table 2. Window and shading elements initial invest- ment costs. 2.4. Life-Cycle Cost Analysis The economic benefits of the three different solar control techniques are assessed with the support of a life-cycle cost analysis. In this research, the calcu- lation is limited to only the window systems costs in relation to the total annual building energy costs. The initial costs for windows, shading elements, and the exhaust air extraction system are reported in Table 2. They were provided by WSP Sweden company [30], with reference to internal projects and by the cost list Sektionsfakta-VVS 19/20 by Wikells [31]. The initial investment and the later maintenance and renovation evaluations are related to the total window area of 750 m2 (27 windows per floor, 10 sto- ries). The maintenance and replacement expenses are evaluated based on a literature review about the dif- ferent window systems elements. Average service life between 20–30 years were considered for the windows and ventilation system, while annual costs between 50–80 SEK/m2 were defined for each solution. Sub- sequently, to evaluate the life-cycle cost of the three options a pre-established working sheet provided by WSP Sweden is used. The calculation considers av- erage prices for the energy carriers to evaluate the annual energy costs of the building over its service life (district heating 680 SEK/MWh, electric cooling and electricity 920 SEK/MWh), together with interest rate (3 %), loan rate (2 %), and price increase for the energy (3 %). 3. Results and Discussion 3.1. Solar Control Techniques In case G3, the introduction of the exhaust air extrac- tion showed a potential reduction of the g-value by 49 % (corresponding to 0.067) for the maximum air flow studied, as presented in Figure 3. Considering the analyses carried out on the office room model, the selected airflow for the exhaust air extraction was 3.24 m3/h, which corresponded to a g- value of 0.073 and an air velocity of 0.11 m/s. The latter configuration provided the best trade-off be- tween air flow increment and heat loads reduction, showing the last considerable improvement in the en- ergy balance of the room with heat loads and heat removal by the air conditioning reductions of respec- tively 43.8 % and 21.7 %. In Table 3 are reported the resulting values for the three techniques used in the further IDA-ICE simulations. Finally, to manage the change of state for each of 439 M. Costanzo, A. G. Mainini, G. Iannaccone et al. Acta Polytechnica CTU Proceedings G1 + S1 G2 G3 + S2 U.M. Clear Drawn Clear Int. 1 Int. 2 Tint Clear Drawn Extr. Tvis % 63 13.8 55.6 16.2 5.2 0.9 55 2.6 2.6 Tsol % 27.3 6 30.4 7.1 2.3 0.4 23.2 1.1 1.1 g-value - 0.312 0.083 0.367 0.127 0.078 0.055 0.267 0.131 0.073 Table 3. Optical and thermal properties of the three window systems. Climate Energy meter G1 G2 % ∆G1−G2 G3 % ∆G1−G3 Scenario [kWh/m2Atemp] C1 Electric Cooling 3.2 2.9 -9.4 % 3.0 -6.3 % Electric Fans 7.2 6.9 -4.2 % 7.2 0.0 % District Heating 23.2 26.2 12.9 % 23.6 1.7 % Total 54.5 57.0 4.6 % 54.9 0.7 % F1 Electric Cooling 24.4 20.6 -15.6 % 21.9 -10.2 % Electric Fans 8.2 8.1 -1.2 % 8.5 3.7 % District Heating 11.9 13.9 16.8 % 11.6 -2.5 % Total 67.7 65.4 -3.4 % 64.9 -4.1 % F2 Electric Cooling 19.1 14.4 -24.6 % 15.2 -20.4 % Electric Fans 8.9 8.0 -10.1 % 8.2 -7.9 % District Heating 18.9 20.2 6.9 % 17.6 -6.9 % Total 69.1 63.9 -7.5 % 62.7 -9.3 % Table 4. Annual building energy consumption in the different years for each solution. these techniques on IDA-ICE, control macros based on levels of incident solar irradiation (W/m2) with an override connected to the outdoor air temperature have been implemented. Different solar irradiation levels have been considered for each façade and cli- mate scenario depending on the characteristics of the window system. 3.2. Current and Future Climates The annual energy demand and ventilation needs re- sults are reported for the three solar control techniques and different climate scenarios in Table 4. The results revealed an increment of the cooling consumption in both the future scenarios, efficiently reduced with the introduction of the electrochromic and internally ventilated solution. At the same time, the heating demand decreased, in accordance with the mitigation of the winter periods, showing a deficit of performance for option G2. The results for the climates F1 and F2 take into consideration an optimization of the fans usage and a combine use of room units and AHU system for the summer period. The latter configuration was due to extreme cooling usage peaks and ventilation air flow initially detected for the scenario F1, caused by the coexistence of high outdoor air temperature and high relative humidity due to the manual alteration of the outdoor air temperature and unvaried relative humidity. In the alternative scenario F2, built with the variation of all the weather parameters, these extreme conditions were not present, and the summer consumption was considerably decreased while the heating demand was increased, always remaining lower than the C1 results. The thermal comfort ranges, i.e. max values of PPD, min and max operative and indoor air temperatures, were respected in all the cases and seasonally analysed, reporting lower PPD values for the winter in the current climate, while more homogeneous results for the future climates. 3.3. Life-cycle Cost Analysis In Figure 4 are reported the results of the life-cycle cost analysis, expressed in Swedish crowns, and divided by investment costs, building energy usage (district heat- ing, electric cooling, electricity), general maintenance, and renovation. The EC technology resulted to be inappropriate for the case study. The costs due to the materials, installation, and renovation overturned the limited benefits in terms of annual energy costs. On the other hand, the internally ventilated solution showed the best results. The initial investment, opera- tional and maintenance costs were improved, remark- ing the potential advantages of such technique also in a long-term perspective in relation to a changing climate. 440 vol. 38/2022 Adapting façade performances to climate change in Northern Europe . . . Figure 4. Graphical representation of all the present values and resulting LCC. 4. Conclusions Following a previous study on the climate change effects on the built environment for a building in Stockholm, this research evaluated the energy con- sumption and indoor thermal comfort variations for an office building equipped with different solar control techniques for the current and future climate. • The internal shading with the extraction offered better performances than without it, for both the current and future climate, especially regarding the cooling demand of the building. • The introduction of the EC technology and the ventilated shading did not considerably modify the energy behaviour of the building in the current sce- nario, while they successfully improved it in both future climates, decreasing the solar thermal load, lowering the maximum airflow required by the build- ing, and thus reducing the size and related issues of the ventilation system. • The initially installed HVAC system resulted inef- ficient to withstand the future climate conditions derived by the only variation of outdoor air tem- perature, pointing out the necessity to evaluate and design new active systems for varying weather conditions. • The results regarding the future scenarios were lim- ited by the intrinsic level of uncertainty within the study of forecasted future climate conditions. • Finally, in the life-cycle cost analysis the internally ventilated option showed the best results, remark- ing relevant potential benefits also in a long-term perspective. References [1] European Commission. European Commission – New rules for greener and smarter buildings will increase quality of life for all Europeans. Energy, Brussels, 2019. [2] International Energy Agency. Data and statistics – Explore energy data by category, indicator, country or region, 2020. [2020-05-07]. https://www.iea.org/data- and-statistics/data-tables [3] M. Santamouris. On the energy impact of urban heat island and global warming on buildings. Energy and Buildings 82:100–113, 2014. https://doi.org/10.1016/j.enbuild.2014.07.022 [4] Intergovernmental Panel on Climate Change. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland, 2014. 151 p. [5] Intergovernmental Panel on Climate Change. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2014. 1535 p. [6] NASA. The causes of climate change, NASA-Earth Science Communications Team, 2020. [7] Boverket. Boverkets byggregler – BBR 28, Boverket, Karlskrona, 2019. [2020-04-29]. https: //rinfo.boverket.se/BFS2011-6/pdf/BFS2019-2.pdf [8] Sweadish Work Environment Authority. Workplace design, SWEA, Solna, 2009. [2020-04-29]. https://www.av.se/globalassets/filer/ publikationer/foreskrifter/arbetsplatsens- utformning-foreskrifter-afs2009-2.pdf [9] N. Kunwar, K. S. Cetin, U. Passe, et al. Full-scale experimental testing of integrated dynamically-operated roller shades and lighting in perimeter office spaces. Solar Energy 186:17–28, 2019. https://doi.org/10.1016/j.solener.2019.04.069 [10] K. Ip, H. Ylitalo, D. Marshall. Environmental performance of external roller blinds retrofit for offices in the United Kingdom, Brisbane, Australia, 2013. [11] A. Cannavale, F. Martellotta, P. Cossari, et al. Energy savings due to building integration of innovative solid-state electrochromic devices. Applied Energy 225:975–985, 2018. https://doi.org/10.1016/j.apenergy.2018.05.034 441 https://www.iea.org/data-and-statistics/data-tables https://www.iea.org/data-and-statistics/data-tables https://doi.org/10.1016/j.enbuild.2014.07.022 https://rinfo.boverket.se/BFS2011-6/pdf/BFS2019-2.pdf https://rinfo.boverket.se/BFS2011-6/pdf/BFS2019-2.pdf https://www.av.se/globalassets/filer/publikationer/foreskrifter/arbetsplatsens-utformning-foreskrifter-afs2009-2.pdf https://www.av.se/globalassets/filer/publikationer/foreskrifter/arbetsplatsens-utformning-foreskrifter-afs2009-2.pdf https://www.av.se/globalassets/filer/publikationer/foreskrifter/arbetsplatsens-utformning-foreskrifter-afs2009-2.pdf https://doi.org/10.1016/j.solener.2019.04.069 https://doi.org/10.1016/j.apenergy.2018.05.034 M. Costanzo, A. G. Mainini, G. Iannaccone et al. Acta Polytechnica CTU Proceedings [12] Y. Ajaji, P. André. Thermal comfort and visual comfort in an office building equipped with smart electrochromic glazing: An experimental study. Energy Procedia 78:2464–2469, 2015. 6th International Building Physics Conference, IBPC 2015. https://doi.org/10.1016/j.egypro.2015.11.230 [13] P. Denz, W. Priedemann, L. Anders. ACT façade – Interior sun shading for energy efficient fully glazed façades. In Final conference of COST TU1403. 2018. [2020-02-06]. https://www.researchgate.net/publication/ 331174454_ACT_Facade_-_Interior_sun_shading_ for_energy_efficient_fully_glazed_facades [14] E. Gustafsson, F. Säfblad. Decreasing g-value by Combining Internal Solar Screen and Exhaust Ventilation – A Numerical Study on what Parameters Affect the Possible Reduction. Master’s thesis, Chalmers University of Technology, Göteborg, 2014. [2020-04-02]. https://publications.lib.chalmers.se/records/ fulltext/215327/215327.pdf [15] Miljöbyggnad. Miljöbyggnad 3.1 – Metodik och. Manual ny byggnad. Sweden Green Building Council, Stockholm, 2020. [2020-06-16]. https://www.sgbc.se/app/uploads/2020/05/Milj% C3%B6byggnad-3.1-Nybyggnad.pdf [16] Sveby. Brukarindata kontor, Sveby, Stockholm, 2013. [2020-07-01]. https://www.sveby.org/wp-content/uploads/2013/ 06/Brukarindata-kontor-version-1.1.pdf [17] European Standard: EN 410:2011 – Glass in Building – Determination of luminous and solar characteristics of glazing, European Committee for Standardization, Brussels, 2011. https://doi.org/10.3403/30219373 [18] European Standard: EN 673:2011 – Glass in building – Determination of thermal transmittance (U-value) – Calculation method, European Committee for Standardization, Brussels, 2011. https://doi.org/10.3403/02351907u [19] International Organization for Standardization: EN ISO 52022-3:2017 – Energy performance of buildings – Thermal, solar and daylight properties of building components and elements, European Committee for Standardization, Brussels, 2017. [20] Lawrence Berkeley National Laboratory. Window & Daylighting – Building Technology & Urban Systems Division. Berkeley Lab - LBNL, 2019. [21] WIS. Advanced Window Information System. TNO - Building and Construction Research, 2006. [22] European Standard: EN ISO 52016-1:2017 – Energy performance of buildings – Energy needs for heating and cooling, internal temperature and sensible and latent heat, International Organization for Standardization, Brussels, 2017. [23] EQUA Simulation AB. Equa – IDA indoor climate and energy, Equa, 2020. [24] Swedish Meteorological and Hydrological Institute. SMHI Research Department - EC-Earth, SMHI, 2020. [25] A. C. Tsaousoglou. The Impact of climate change on the energy demand and indoor climate of an apartment building in Stockholm. Degree project, Royal Institute of Technology, Stockholm, 2019. [2020-04-22]. http://kth.diva-portal.org/smash/get/diva2: 1388648/FULLTEXT01.pdf [26] Swedish Government Official Reports. Sweden facing climate change – threats and opportunities. Edita Sverige AB, Stockholm, 2007. [2020-04-23]. https://www.government.se/49b75f/contentassets/ 5f22ceb87f0d433898c918c2260e51aa/sweden-facing- climate-change-sou-200760 [27] EnergyPlus. EnergyPlus - Weather data, EnergyPlus, 2020. [28] Energy and Climate Change Division. CCWorldWeatherGen – Energy & Climate Change. University of Southampton, Southampton, UK, 2020. [29] Intergovernmental Panel on Climate Change. Climate Change 2001 – Synthesis Report. IPCC, Cambridge, UK, 2001. [2020-07-30]. https://www.ipcc.ch/site/ assets/uploads/2018/05/SYR_TAR_full_report.pdf [30] WSP Sverige. VVS och Energi avdelning, WSP Sverige, 2020. [31] Wikells. Sektionsfakta-VVS 19/20, Wikells Byggberäkningar, 2019. 442 https://doi.org/10.1016/j.egypro.2015.11.230 https://www.researchgate.net/publication/331174454_ACT_Facade_-_Interior_sun_shading_for_energy_efficient_fully_glazed_facades https://www.researchgate.net/publication/331174454_ACT_Facade_-_Interior_sun_shading_for_energy_efficient_fully_glazed_facades https://www.researchgate.net/publication/331174454_ACT_Facade_-_Interior_sun_shading_for_energy_efficient_fully_glazed_facades https://publications.lib.chalmers.se/records/fulltext/215327/215327.pdf https://publications.lib.chalmers.se/records/fulltext/215327/215327.pdf https://www.sgbc.se/app/uploads/2020/05/Milj%C3%B6byggnad-3.1-Nybyggnad.pdf https://www.sgbc.se/app/uploads/2020/05/Milj%C3%B6byggnad-3.1-Nybyggnad.pdf https://www.sveby.org/wp-content/uploads/2013/06/Brukarindata-kontor-version-1.1.pdf https://www.sveby.org/wp-content/uploads/2013/06/Brukarindata-kontor-version-1.1.pdf https://doi.org/10.3403/30219373 https://doi.org/10.3403/02351907u http://kth.diva-portal.org/smash/get/diva2:1388648/FULLTEXT01.pdf http://kth.diva-portal.org/smash/get/diva2:1388648/FULLTEXT01.pdf https://www.government.se/49b75f/contentassets/5f22ceb87f0d433898c918c2260e51aa/sweden-facing-climate-change-sou-200760 https://www.government.se/49b75f/contentassets/5f22ceb87f0d433898c918c2260e51aa/sweden-facing-climate-change-sou-200760 https://www.government.se/49b75f/contentassets/5f22ceb87f0d433898c918c2260e51aa/sweden-facing-climate-change-sou-200760 https://www.ipcc.ch/site/assets/uploads/2018/05/SYR_TAR_full_report.pdf https://www.ipcc.ch/site/assets/uploads/2018/05/SYR_TAR_full_report.pdf Acta Polytechnica CTU Proceedings 38:436–442, 2022 1 Introduction 2 Methodology 2.1 Stockholm Case Study 2.2 Solar Control Techniques Evaluation 2.3 Climate Scenarios 2.4 Life-Cycle Cost Analysis 3 Results and Discussion 3.1 Solar Control Techniques 3.2 Current and Future Climates 3.3 Life-cycle Cost Analysis 4 Conclusions References