Despite ample technological advancements, the building industry is still seen as an unsustainable activity. To counteract this, building development is now being requested to be more sustainable. Due to the increasing complexity of sustainable projects’ criteria, the project manager’s role, tasked with the overall management of a building’s different development phases, is changing, becoming increasingly crucial for the attainment of pre-established sustainability goals. Based on this premise, the research presented in this paper is a pilot study set to preliminarily establish and identify a set of project management processes and supporting practices from existing literature, and gauge their significance and possible added value provided. This was done via a purposely designed questionnaire distributed locally, in Malta, and globally amongst established project managers. Notwithstanding the preliminary nature of the study some interesting results were obtained. Among the main outcomes of the study, it is observed how all respondents are very aware about sustainability issues and that their decision-making role places them in an optimum position to bring forward a sustainability agenda for a particular project. In terms of intervention, pre-construction (43%) and construction (28%) were considered to be the main stages were a project manager usually gives the highest input. However, various challenges were also highlighted by the respondents, including clients’ refusal to commit increased capital (34%), the requirement for further training (33%), and the lack of incentives aimed towards increasing the sustainability of projects (22%).

One parameter that may affect the performance of a ground source heat pump is the shank-space, the center-to-center distance between the two branches of a vertical U-tube used in a ground heat exchanger. A 3D steady-state computational fluid dynamics (CFD) model of a U-tube ground heat exchanger was used to investigate the influence of varying shank-space on the thermal performance of two isolated vertical shallow U-tubes, one 20 m deep and the other 40 m deep, given that most existing research focuses on systems making use of deeper boreholes. The models adopt an innovative approach, whereby the U-junction at the bottom of the U-tube is eliminated, thus facilitating the computational process. The results obtained show that, although the temperature drop across the U-tube varies for different shank-spaces and is lowest and highest for the closest and the widest shank-spaces, respectively, this temperature drop is not linear with increases in shank-space, and the thermal performance improvement drastically diminishes with increasing shank-space. This indicates that, for shallow U-tubes, the temperature drop is more dependent on the length of the pipework.

As per general provisions of European Directive 2010/31/EU on the energy efficiency of buildings (recast), the Lithuanian government transposed the Directive into Lithuanian national law. In the process, the Lithuanian government prepared strategic documents in the field of energy performance and renewable energy that were integrated together through the National Energy and Climate Plan for 2021–2030 (NECP). To better understand the current situation vis-à-vis energy performance, the main characteristics of buildings pertaining to the Lithuanian multi-apartment building stock, classified according to their energy performance class, are analysed and discussed in this paper. Through the exploitation of data from the national Energy Performance Certificate (EPC) register, an overview of the energy performance of the existing Lithuanian residential building stock is presented along with an analysis of the unused potential energy savings pertinent to this building category. The results obtained from the analysed data of energy consumption in buildings shows that the policies adopted over the years were successful in improving the building stock, promoting the move towards the specifications required by a Class A++ (nearly zero energy buildings—NZEB) by 2021. The results show that this was primarily achieved by a significant reduction in the thermal energy used for space heating.

The general consensus among academics is that the spatio-temporal humidity distribution is more or less uniform in an indoor space. This has, for the large part, not yet been proven by an academic study; subsequently, this paper aims to demonstrate that this is not always true. The paper makes use of a validated transient CFD model, which uses the Low Reynolds Number k-$ϵ$ turbulence model. The model simulates people in a room at a constant skin temperature and emitting a constant source of humidity using source terms in the species equation. The model is eventually used to predict the implications of having a high source of humidity, in the form of occupancy, on the micro-climate’s spatio-temporal humidity distribution. The results for the high-occupancy case show that different locations experience various amounts of humid air, with a 31% difference between the lowest and highest locations. The amount of water vapor in each person’s proximity is deemed to be highly dependent on the flow of the inlet jet, with the people farthest from the jet having an overall less mass of water vapor in their proximity over the two-hour experimental period. This paper has concluded that there are, in fact, cases where the humidity non-uniformity inside an interior environment becomes substantial in situations of high occupancy. The results of this paper may be useful to improve the design of HVAC systems.

The Double C Block (DCB) is an innovative composite Concrete Masonry Unit (CMU) developed to offer enhanced thermal performance over standard hollow core blocks (HCBs). The DCB features an original design consisting of a polyurethane (PUR) foam inserted between two concrete c-shaped layers, thus acting as the insulating layer and the binding agent of the two concrete elements simultaneously. The purpose of this research is to describe the results obtained when assessing the thermal transmittance (U_DCB and U_HCB) of these blocks using three different methodologies: theoretical steady-state U-value calculations, numerical simulation using a Finite Element Method (FEM), and in situ monitoring of the U-value by means of the Heat Flow method (HFM). The results obtained show that the three methodologies corroborated each other within their inherent limitations. The DCB showed a performance gap of 52.1% between the predicted FEM simulation (U_DCB was 0.71 W/(m²K)) and the values measured via HFM, which converged at 1.47 W/(m²K). Similarly, a gap of 19.9% was observed when assessing the HCB. The theoretical value via FEM of U_HCB was 1.93 W/(m²K) and the measured one converged at 2.41 W/(m²K). Notwithstanding this, the DCB showed superior thermal performance over the traditional block thanks to a lower U-value, and it complies with the Maltese building energy code. Further improvements are envisaged.

In Europe, the energy consumed for heating and cooling purposes by the hospitality sector is significant. In island economies such as that of the Mediterranean Island of Malta, where Tourism is considered essential to the local economy, energy consumption is perhaps even more significant, and energy-efficient systems, or the use of renewable energy, are often listed as possible solutions to counter this. Based on this premise, the research contained in this paper presents an investigation on the technical and financial feasibility of using Combined Heat and Power (CHP) and Combined Cooling, Heating, and Power (CCHP) systems for the hospitality sector in Malta. Using a supply–demand design methodology, the research made use of the software package RETScreen to model the electrical and thermal demand of a number of hotels ranging from 3- to 5-star hotels. Based on these modelled hotels, different scenarios were simulated to analyze the technical and financial implications of installing a CHP in these modelled hotels. A number of parameters, including thermal size matching, presence of financial grants, electricity tariffs, feed-in tariffs, and fuel prices, were tested out for a total of 144 scenarios. Results showed that the parameters having the highest impact were those of a financial nature. Specifically, the study showed that the 4-star hotels considered were the hotels which would benefit the most from having such systems installed.