Overheating in dwellings is a global concern that is increasing due to global warming and more frequent and extreme heatwaves. This study assesses the relationship between different building parameters (built period, floor level, orientation, window area and solar shading) and compares indoor overheating hours during summer in twelve apartments monitored in Pamplona (North of Spain). They were selected as samples from different Spanish built periods related to different energy regulations, without mechanical cooling and with some kind of exterior solar shading. Overheating hours were calculated using the UNE-EN 16798 standard, which establishes a maximum acceptable operative temperature. This limit is adaptive and it is defined as the exponentially weighted running mean of the daily outdoor temperature. Multilevel mixed-effects linear and logistic regressions were used to analyse and compare overheating hours. Floor level, window area and solar shading were the parameters that showed a significant relationship with indoor overheating hours (p < 0.01). Orientation and built period did not reach a statistically significant value (p > 0.01). It is particularly noteworthy that the apartments built under the current Spanish Energy Regulations (after 2006) do not show a significant reduction in indoor overheating hours compared to those built without any energy regulations. This assessment reveals that current building energy regulations may not be enough to avoid overheating or ensure adaptation to warmer conditions. Therefore, this study contributes to establishing the main building parameters to improve in order to adapt Spanish apartment buildings to warming conditions in temperate climates.

Heat waves are expected to increase the use of air conditioning (AC), deriving in higher energy consumption. This research aims to determine whether thermal insulation is an effective retrofit strategy for tackling overheating. Four occupied dwellings in southern Spain were monitored: two houses built prior to any thermal criteria and two with current thermal standards. Thermal comfort is assessed considering adaptive models and user patterns for the operation of AC and natural ventilation. Results show that a high level of insulation combined with a proper use of night-time natural ventilation can increase thermal comfort hours under heat waves, lasting 2-5 times longer than in poorly-insulated houses and with up to 2 degrees C temperature difference at nights. Long-term effectiveness of insulation under extreme heat presents a better thermal performance, especially in intermediate floors. Yet, the activation of AC usually occurs with indoor tempera-tures of 27-31 degrees C, regardless of the envelope's solution.

Adaptive facades are a promising choice to achieve comfortable low-energy buildings. Their effective performance is highly dependent on the local boundary conditions of each application and on the way the dynamic properties are controlled. The evaluation of whole building performance through building performance simulation can be useful to understand the potential of different Adaptive opaque facades (AOF) in a specific context. This paper evaluates through dynamic simulations promising design solutions of AOF for a residential building use in six different climates. It quantifies the total delivered thermal energy of 15 typologies of AOFs which consist of alternative adaptation strategies: (i) variation of solar absorptance of the cladding, (ii) variation of the convective heat transfer of air cavities and (iii) adaptive insulation strategies. For the first time, it also quantifies the performance of AOF which combine more than one adaptation strategy. The results show that the variation of the heat transfer by means of Adaptive Insulation components has the most significant impact on the reduction of the thermal energy use. The variation of the solar absorptance has also a significant positive impact when reducing heating consumption, but only if this adaptation strategy is actively controlled and combined with Adaptive Insulation components.

The COVID pandemic has strongly affected daily life both in Spanish schools and worldwide. Providing the best environmental conditions for children allowing face-to-face learning with healthy and safe indoor spaces is a challenge. In the present study, empirical research about how these environmental conditions change with COVID is presented comparing the situation from March 2020 to January 2021. The methodology combines surveys conducted in nine schools with a case study in a selected school where a detailed monitoring of the building was developed during both heating seasons. This data analyzes the impact of the new COVID prevention protocols on indoor environmental conditions (especially those related to natural ventilation). Results show a mean CO2 reduction of 1,400 ppm, having in the second term values around 1,000 ppm, although temperatures diminished nearly 2 degrees C to mean values of 18 degrees C. Evolution of temperature and CO2 concentration throughout the day was also analyzed, being these indoor conditions especially important for the children with poorer health. Mechanical ventilation with heating recovery should complement natural ventilation, at least during the coldest months or hours of the day, although systems have to be carefully designed and installed to work effectively. (C) 2021 The Authors. Published by Elsevier B.V.

The lack of green open spaces undermines the environmental and social quality of tropical highly-dense cities (i.e. raises urban temperatures, limits social interaction). The goal of this study, which focused on environmental aspects, was to identify underlying factors (i.e. hypothetical constructs) in semi-outdoor spaces within building forms that explain their microclimatic behaviour, thermal comfort levels, and clustering. Sixty-three semi-outdoor spaces in four high/mid-rise building forms of Singapore were stud-ied using microclimatic data collected from field measurements and analysed via inferential statistical methods (e.g., exploratory factor analysis, multivariate regression analysis, and hierarchical clustering analysis). Findings demonstrate: (1) that spatial attributes (i.e. height, depth, void, solid, total frontage, open frontage, area, volume, perimeter, sky view factor, green plot ratio) are manifestations of three underlying factors: volume porosity (VP), perimeter openness (PO) and exposure to sky (ES); (2) that VP and PO are sig-nificantly associated with air velocity and predicted thermal comfort; and (3) that vertical breezeways appear to be the most thermally comfortable cluster due to high VP and low PO. This study sheds new light on the spatial nature of semi-outdoor spaces, which designers can consider in order to enhance wind movement for promoting thermally comfortable semi-outdoor environments in highly-dense Singapore.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Renovation at district scale is a key strategy to reduce CO2 emissions by optimising the implementation of renewable energy sources and taking advantage of economy of scale. This paper focuses on analysing good practice examples on energy renovations at district scale. The paper adapts a qualitative research methodology in four phases, including the multi-perspective analysis of nine exemplary renovation projects in six European countries, including identification of drivers and barriers of different stakeholders. It is found that the drivers for a district renovation are not restricted to energy savings, but typically also include improving the overall quality of life as well as the image and economic value of a district. Moreover, the need for financial models that can alleviate split-incentive problems between investors and resident organizations is identified. Barriers for carrying out a district renovation include that there is a need to comply with energy standards, that the renovation scope had to be limited to avoid a noticeable rent increase and that resettling of tenants during the renovation is often not possible. Lessons learned include that good communication amongst the different stakeholders, especially with residents, plays a key role for the success of the project. Furthermore, a strong leadership is needed to coordinate activities due to the great number of stakeholders.

Renovation at district scale is a key strategy to reduce CO2 emissions and energy consumptions by optimising the implementation of renewable energy sources and taking advantage of economies of scale. In this context, this paper focuses on assessing the positive impacts and difficulties after the energy rehabilitation of thermal envelopes in two buildings that belong to two different District Heating systems. The methodology is based on the comparative analysis of indoor temperatures data and energy consumption data of 17 monitored dwellings. The results showed a significant association between the improvement of envelopes and the increase of indoor temperatures in winter (ß=0,644). Due to some technical and social barriers, the heating system was not regulated after the rehabilitation, so energy consumption was unnecessarily high, there were situations of indoor overheating in winter (maximum average indoor temperatures between 24-26°C) and these issues produced dissatisfaction on neighbours. In order to avoid these negative consequences, some recommendations are provided, such as informing neighbours about expectations in each step of the long rehabilitation process, reconsidering payments to promote the envelope rehabilitation but maintaining a fixed cost to protect vulnerable groups, and promoting post-occupational studies that contribute to the viability and up-date of this kind of District Heating systems.

In highly dense tropical cities, a semi-outdoor space (SOS) is frequently used as a social space within tall building forms where people can interact and connect. Thermal comfort in SOSs within tall buildings, however, may vary depending on the type and form attributes that define it. This study classifies 63 SOSs in four tall buildings of Singapore into five types based on literature review: perimeter buffers, sky terraces, horizontal breezeways, breezeway atria and vertical breezeways. Findings suggest that the five SOS types perform differently in terms of thermal comfort (based on PMV*), environmental parameters (air temperature, mean radiant temperature, relative humidity, and air velocity), and building form attributes (height-to-depth ratio, open space ratio, and green plot ratio). Of these five, vertical breezeways and horizontal breezeways are the most thermally comfortable for all activities during a typically warm hour. It is postulated that higher thermal comfort levels in these SOS types are linked to form attributes that enhance air velocity. This study examines the pros and cons of each SOS type in terms of thermal comfort in their role as communal spaces in tall buildings situated within a highly dense tropical city.

Year-round high temperatures and humidity in the Tropics, coupled with poor design decisions and climate change, can cause indoor environments to overheat, affecting health and increasing energy demand and carbon emissions. Passive cooling could help lower the indoor overheating risk. Given the gap in the relative influence of passive cooling design strategies on lowering the indoor overheating risk in tropical locations, this study investigated their impact in two warm tropical cities (i.e., Tegucigalpa and San Pedro Sula), considering both current and future climate scenarios, with a total of 3840 thermal simulations performed. Indoor overheating risk in apartment-type dwellings was assessed using two metrics (i.e., hours of exceedance and the indoor overheating degree), and considering fixed and adaptive thermal comfort limits. Simulation results show that the overheating risk can be significantly lowered in these tropical contexts using solely passive cooling strategies as heat adaptation measures. Multivariate regression models demonstrate that natural ventilation, wall absorptance, the solar heat gain coefficient, and semi outdoor spaces have the greatest impact in lowering the risk in vertical social housing projects. This study emphasizes the importance of passive cooling and overheating protection design strategies in tropical building codes and building design while considering current and future risk. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

This study delved on the role of semi-outdoor spaces (SOS), as form-based strategies, in providing enhanced, thermally comfortable environments in highly dense urban contexts. A sample of sixtythree (63) SOS was studied, within four different mid-rise and high-rise buildings located in the warm-humid tropical city of Singapore. It was found: (i) that SOS may act as thermal buffer spaces; (ii) that microclimate creation in SOS is linked to form, specifically to geometrical variables such as void-to-solid ratio, height, height-to-depth ratio, height from ground level, green plot ratio and open space ratio, which influence significantly the environmental factors of air temperature, mean radiant temperature, air velocity and relative humidity; (iii) that some aforementioned geometrical variables (height-to-depth ratio and open space ratio) are linked to thermal comfort when estimated with SET* and PMV* thermal indices; (iv) and that thermal comfort (between-1 and +1 PMV*) can be achieved in SOS considering a typical Singaporean outdoor CLO of 0.3, especially for 1 MET (85.7% of SOS). In the context of Singapore, this study demonstrates that incorporating SOS to mid-rise and high-rise building forms promotes the creation of thermally comfortable microclimates suitable for human activity, even during the hottest hours. (C) 2020 Elsevier B.V. All rights reserved.

In Spain and other Mediterranean countries, some museums lack cooling and ventilation systems. They usually are located in historical buildings with heritage protection requirements. This is particularly complex in a building with a use that has to attend to comfort conditions for visitors and workers, and to very specific and demanding indoor thermal and relative humidity fluctuations for the conservation of its artwork collection. So, current requirements for museums and the hardening of summer conditions and the heatwaves events related to Climate Change require facing refurbishment measures usually related with the building envelope and the implementation of HVAC systems that require energy. This chapter presents a case study of a museum in the north of Spain, that has monitored data of 10 years (temperature and relative humidity), more detailed monitored data of 2019 summer with two very early heatwaves, and the analysis of different passive measures to implement attending to the characteristics of the building (with high thermal mass, without solar shading, and without ventilation and AC systems) in order to achieve suitable environmental conditions in a museum and with the lowest energy consumption, and ¿ready¿ for the hardening of summer conditions due to global warming.

Two recently completed high-rise residential developments, located side-by-side in a neighbourhood in Singapore, are compared in a post-occupancy study. Both have near identical demographics, are exposed to the same microclimate, and constructed with a similar palette of materials. The primary difference is form. One has a high degree of porosity with inner voids that act as conduits for natural air flow and offer a sheltered space for social engagement. The other is more compact, less porous and has social spaces attached to the building¿s exterior. The study included surveys of residents, behavioural observations and environmental measurements. On three counts ¿ self-reported energy use, thermal comfort and social interaction ¿ the former appears to be more successful than the latter. Findings suggest that building form affects multiple outcomes at once. A form strategy that lowers energy use, for instance, can also improve social engagement. The implication of this socioenvironmental approach to form-making is discussed in the context of high-density tropical typologies.

Adaptive or Intelligent façades are those that can interact with users and dynamically vary their performance or properties (controlling thermal or solar energy, air flow and/or daylight) in response to changing external conditions and indoor demands. Consequently, adaptive façades could help to ensure occupant comfort, health, well-being and satisfaction, while allowing resource-efficient building operation. However, effective adaptive façade solutions that provide an optimal balance between user comfort, satisfaction and energy efficiency cannot be achieved without knowledge of the multidisciplinary complexity of the user-façade interaction. The main objective of this paper is to preliminary review and analyse the existing literature on user interaction with intelligent buildings, especially with façades, and to propose a conceptual framework to capture the multi-disciplinary and multi-domain complexity of user interaction with adaptive façades. The interaction between adaptive façades and occupants is then modelled as a closed loop of information and action exchange. This paper concludes indicating which are the future research needs to be addressed in order to define what is a satisfactory interaction strategy between occupants and façades.

Adaptive façades have emerged strongly in extreme climate countries, as their behaviour contributes to optimize the energy efficiency of buildings and the well-being of the occupants. Its development in temperate climates could contribute to the achievement of European environmental objectives for 2020 and 2050. These will only be obtained if occupants accept and know how to use buildings, hence the need for in-use assessments of buildings, especially of the most innovative ones. In the literature review, very few postoccupational evaluations or assessments of Adaptive Façades have been found, even less in temperate climates, where the façade must adapt to varied conditions at a short time scale. This article shows the Case Study of an office building, the Media-TIC, located in Barcelona (Spain), which has a Mediterranean Climate with mild winters and warm summers. Media-TIC has two different Adaptive Facades facing southeast and southwest, and the innovative technology consists on inflatable sheets and cushions made of ETFE (Ethylene Tetrafluor Ethylene). The study was conducted with a small sample of occupants distributed in different floors and orientations of the building. The behaviour of the Adaptive Façades, the occupants¿ acceptance in respect to the innovative system and the possibilities for its improvement were analysed.

The assessment of adaptive facades presents a challenge because there is no established evaluation strategy to systematically reach this goal and many of the available building energy standards and codes have limited applicability for such advanced facades system. This paper reviews current evaluation methods for assessing adaptive facades system through a literature review. It also discusses occupant behaviour, post occupancy evaluation and commissioning issues and presents the procedures. The paper is part of the activities of Working Group 3 in COST Action TU1403 - Adaptive Facades Network. So far we could not find a protocol for assessment of adaptive facades. The reviewed literature is scattered lacking a focus on adaptive facades. There is no agreement on defining what are adaptive facades (sometimes named intelligent, smart, dynamic). We could define specialized technology monitoring techniques to assess the performance of technologies such as fabric-integrated solutions (e.g. electrochromic glazing, phase-change materials, building-Integrated Photovoltaics with heat recovery (BIPV/T, shade shutters) and advanced controls. The review is used to identify gaps in existing assessment methods and helps develop strategies for the holistic evaluation and assessment of adaptive facade systems as part of high performance buildings.