The European Green Deal defined by the European Commission on December 2019 presents an ambitious set of measures for the European Union and its citizens to accomplish the challenge of climate change, making Europe until 2050 the first neutral continent, where there are no net emissions of greenhouse gases. The Passive House (PH) concept has the same ambitious goal, targeting the reduction of the carbon footprint while promoting a construction design that gives primacy to the optimum energy balance, assuring comfort and quality with a minimum impact on the final building cost and operation. However, the PH concept is still not an easy process to implement in the traditional construction sector, especially in South European territory, as is the case of Portugal. Contextually, the present study through the discussion of a case study research method applied to European PH successful experience, has defined guidelines for the implementation of this concept within sustainable development principles. The methodology strategy starts with the information collection from Hanover, Brussels, and Tyrol case studies. Then, a statement regarding the current situation of Portugal in respect of the PH numbers and policies was performed. Moreover, the information gathered, as well as the experience of learnt lessons, were compared to the Portuguese reality. As a final procedure, barriers and obstacles for the Portuguese case have been identified through the analysis and understanding of the country’s social dynamics, and also with the crossing of sustainable development principles. Thus, the present research enables us to propose guidelines to increase the PH implementation in Portugal.

The radiant floor system market is growing rapidly because Europe is moving toward a low-carbon economy and increased awareness about environmental sustainability and energy efficiency, stimulated by the ambitious EU Energy Efficient Directive and nZEB challenge. The high growth rate of the market share is due to the involvement of homeowners in the specifications of their living commodities, so they are thus willing to invest more at the initial stage to obtain long-term benefits and lower energy exploration costs. We performed an experimental campaign over three slabs with a hydronic radiant floor system of equal dimensions, shape, and pipe pitch with different screed mortar formulations to assess their performance throughout a heating/cooling cycle. The temperature at different heights within the interior of the screed mortars and at the surface were monitored. The results revealed that an improved screed mortar has a relevant impact on the efficiency of the system. Moreover, a three-dimensional transient heat transfer model was validated using the experimental data. The model was used to evaluate the impact of different finishing materials, namely wood, cork, ceramic, and linoleum, on the floor surface temperatures. The results showed differences of 15% in the surface temperature when using different floor finishing solutions.

Lightweight construction is experiencing a significant market implementation with sustained growth both for new buildings and retrofitting purposes. Despite the acknowledged advantages of this type of construction, their reduced thermal inertia can jeopardize indoor thermal comfort levels while leading to higher energy consumption due to high indoor temperature fluctuations and overheating rates. The incorporation of phase change materials (PCMs) into constructive solutions for lightweight buildings is a promising strategy to guarantee adequate thermal comfort conditions. Particularly, the utilization of mortars embedding PCMs as an indoor wall coating for new and existing buildings represents a solution that has not been widely explored in the past and needs further development and validation efforts. This work pursues the analysis of the thermal regulation effects generated by two thermally-enhanced mortars incorporating microencapsulated PCMs with different operating temperature ranges. To that end, an experimental campaign was conducted in Valladolid (Spain) to address the investigation of the proposed solution under a real-scale relevant environment. The proposed mortars were applied as an indoor coating to the envelope of a single-zone lightweight construction that was monitored (under different weather conditions along 1-year monitoring campaign) together with an identical building unit where the mortar was not added to the constructive base layer. The analysis of indoor temperature fluctuations under free-floating operating mode as well as the energy consumption of HVAC equipment under controlled-temperature operation was specifically targeted. Results derived from the continuous monitoring campaign revealed lower temperature fluctuations during summer and shoulder seasons, reducing indoor temperature peaks by 1–2 °C, and producing a time delay of 1–1.5 h into the temperature wave. A clear reduction in energy use due to the incorporation of the PCM-based indoor coating panels is also observed. Thus, this experimental research contributes to proving that the use of innovative mortars incorporating embedded PCMs enables the development of high-end efficient building solutions with innovative materials towards a sustainable built environment.