Currently, fire-resistance requirements for exterior wall insulation are being progressively tightened. Insulation systems must simultaneously deliver excellent thermal performance and achieve Class A fire resistance. Insulation boards made from mineral wool (rock wool or glass wool) offer Class A fire rating, low thermal conductivity, and the additional advantages of being free from hollowing, cracking, and detachment, which is why they are receiving increasing attention.

　　Currently, there are three main types of wall insulation widely promoted in China:

　　1. Internal thermal insulation of exterior walls

　　2. External Wall External Thermal Insulation

　　3. External Wall Self-Insulation

　　1. Internal thermal insulation of exterior walls is the most economical and simplest method; however, it has the following drawbacks:

　　① Thermal bridge treatment at beam-column joints is challenging;

　　② The insulation layer requires a substantial thickness and encroaches on the usable indoor floor area;

　　③ It has obvious drawbacks, such as interfering with secondary renovations and the installation of additional hanging fixtures, which can cause significant inconvenience; moreover, any problems that arise can have a substantial impact on residents during repairs. As a result, it has now been largely replaced by other insulation methods, including in high-rise buildings.

　　2. External wall external thermal insulation is a highly ideal approach to wall energy conservation, both in terms of thermal performance efficiency and in terms of enhancing the overall structural stability of the building by reducing temperature differentials across the envelope. It is particularly the optimal choice for thermal insulation of shear walls in high-rise buildings. Especially after the energy-saving standard was raised from the original 50% to 65%, the corresponding limit on the overall heat transfer coefficient of exterior walls was further reduced, thereby further highlighting the rationality of the external wall external thermal insulation solution.

　　3. External wall self-insulation is a structural insulation approach that is currently being explored and promoted in many regions. From the perspectives of design and construction, it is relatively convenient; however, from the standpoint of seismic and shear resistance design for high-rise buildings, its promotional value is limited. Moreover, addressing thermal bridging at beams and columns is challenging, and issues such as plastering lightweight, energy-efficient masonry infill walls and preventing cracking remain poorly resolved, leading to potential risks like wall water infiltration and detachment of the decorative finish. The use of lightweight infill materials as exterior wall components is still in the exploratory stage.

　　External wall external thermal insulation technology offers remarkably significant advantages: it eliminates thermal bridges in buildings and prevents condensation on wall surfaces during winter; it protects the load-bearing structure by reducing thermal stresses, thereby extending its service life; it increases the usable floor area compared with internal insulation; when applied to energy-saving retrofits of existing buildings, it does not disrupt the daily lives of existing residents; and it enhances the aesthetic appeal of buildings. At the same time, since residential buildings in China are predominantly constructed with brick–concrete structures—characterized by substantial mass and high thermal capacity—external wall external thermal insulation ensures excellent thermal stability, resulting in warm interiors in winter and cool interiors in summer, thus improving living comfort and enhancing people’s quality of life. Consequently, this approach is increasingly favored by the public. In today’s context, where energy conservation and environmental protection are of paramount importance, vigorous development of scientifically sound external wall insulation technologies is of great practical significance for conserving energy, optimizing the environment, and promoting improvements in the human living environment. Recommended reading.