**Preface to "Volume II: Thermal Behaviour, Energy Efficiency in Buildings and Sustainable Construction"**

As is well known, energy and sustainability are two of mankind's major concerns at present. Given the share of energy consumption belonging to the buildings sector, it is very important to search for innovative design solutions and the optimal thermal performance of buildings to reduce energy bills and greenhouse gas emissions, while maintaining the occupants' comfort levels. Additionally, given the environmental burdens of the construction sector, the search for more environmentally responsible processes and a more efficient use of resources is currently attracting attention.

This second volume of this Special Issue (SI), published in the Energies journal, is dedicated to the analysis of recent advances in the following main issues: (1) improvements in the thermal behavior of a building's elements (walls, floors, roofs, windows, doors, etc.), (2) energy efficiency in buildings, and (3) sustainable construction. The main goal is to compile scientific works within these topics, making use of different possible research approaches, such as: experimental, theoretical, numerical, analytical, computational, case studies, and mixtures of these. This book compiles a set of original research works with academic excellence and scientific soundness.

The Guest Editor would like to express their sincere and deep gratitude for all the scientific contributions from authors among prestigious worldwide scientists, as well as to the reviewers who significantly improved the quality of these manuscripts. Moreover, I would like to acknowledge the research project Tyre4BuildIns: "Recycled tyre rubber resin-bonded for building insulation systems towards energy efficiency", supported by FEDER funds through the Competitivity Factors Operational Programme (COMPETE) and by national funds through Foundation for Science and Technology (FCT), within the scope of the project POCI-01-0145-FEDER-032061, which contributed three scientific articles to the first volume and one paper to this SI (Volume II). Additionally, the Guest Editor also wants to acknowledge the support provided by the following companies, who were partners of the research project Tyre4BuildIns: Pertecno, Gyptec Iberia, Volcalis, Sotinco, Kronospan, ´ Hulkseflux, Hilti and Metabo.

> **Paulo Santos** *Editor*
