The article presents the results of a set of hygrothermal experiments of an external wall insulated with an ETICS. As an add-on to previous studies, thermal insulation in the form of polystyrene with an additional horizontal strip of mineral wool was used. Laboratory tests were carried out in accordance with ETAG 004. The ETICS test rig was composed of combustible expanded polystyrene foam (EPS) and horizontal strips of noncombustible mineral wool (MW) fire barriers over windows. The physical and mechanical properties of four types of finishing renders (without an additional reinforcement mesh in base coat of the fire barriers) were analyzed across full hygrothermal cycles in a climate chamber. Temperature sensors were mounted onto different ETICS layers to collect thermal data during the weathering. The testing of ETICS regarding their hygrothermal performance revealed that there were no visible defects on any renderings and over the junctions depending on the type of used insulation materials. Results also showed that the joints of EPS and MW have approximately half of their bond strength from polystyrene strength.

Sound insulation design for structural glazed façade is an important task in environmental noise control, as increased continuously repeated noise is a significant factor impacting on people’s well-being and is associated with a negative impact on their health. For façades, in addition to sound insulation, requirements for safe use and high energy efficiency are also usually raised, which partly determine the composition of the glazing: triple insulating glass unit (IGU) with inner safety laminated glass sheet. Therefore, the aim of the research was to investigate the structural sealed façade structure with triple IGU and to determine the effect of the thickness of ordinary and laminated glasses, their position in the IGU, the thickness of the gas cavities, and the mass of the structural frame on the sound insulation level of structural glazing. Experimental measurements of the sound insulation index of the investigated façade elements with IGU of various constructions were performed in an acoustic reverberation chamber according to standard procedures. The result of the study indicated that the use of the second laminated glass in a triple IGU is inefficient, the highest sound insulation indicators are achieved by increasing the thicknesses of the external glass sheet and the gas cavity; increasing the mass of the frame also has only little effect on the sound insulation of the structural glazing.

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.

The present local built environment has a common thermal comfort problem namely that most dwellings have a great reliance on electricity for environmental control indoors. The main objective of this research work was to offer a practical and cost-effective working solution to this problem. The feasible energy–saving measures that can be retrofitted to an existing dwelling were designed and applied to an existing building; a top third floor flat in Birkirkara, Malta, thus converting it into a thermally comfortable minimum energy home. The indoor climate of the subject flat, its mirror image apartment and the Birkirkara microclimate were monitored for one year and the necessary tools to analyse this data were utilised: a psychrometric chart analysis with Malta’s defined thermal comfort zones. Compared to its microclimate and the mirror apartment, the results show that the subject flat managed to keep a constant and very comfortable indoor climate across both the hot and cold seasons. It is only for a small portion (a total of 9 out of 122 days – 7% in summer and 16 out of 121 days – 13% in winter) that the energy–saving retrofit measures did not fall within the thermal comfort zones limits. This case study also shows that the combined energy saving retrofit measures had a payback period of 15 years, which eventually pays off with a surplus of over €700.

This paper is the research output of the laboratory ageing of external thermal insulation composite systems (ETICS). This was carried out in order to study the changes in properties of systems consisting of combustible and non-combustible thermal insulation materials, and four different types of finishing renders. Four types of the widely used, thin-layer facade rendering systems were subjected to hydrothermal cycles in a climate chamber in conformity with ETAG 004 guidelines. Analysis of the physical and mechanical properties (i.e., variation of temperature, water absorption, bond strength and mechanical resistance) of four types of ETICS are presented. This study indicates that there are no visible defects on any renderings over the junctions between polystyrene foam (EPS) and mineral wool (MW) materials when applied in ETICS.