## 2 Methods  
In dense urban developments, a common problem is deep excavations which are adjacent to existing buildings. In this case, it is important to assess the impact of excavation construction on the surrounding soil and adjacent buildings, and also to estimate soil settlement for the proper design of the new structure. From a technical point of view, the condition of adjoining buildings is usually critical due to the weakness of the structural system or the shallow depth of the foundations. As a result of deep excavations, lateral and vertical soil displacements occur. Lateral loads cause bending moments and foundation deflections, which can lead to dangerous increases in stress or damage to the structure. Many failures have occurred due to the inadequately supported excavations, walls and foundations of existing buildings. The choice of the support system is affected by many factors. These include, for example, the type of soil, the type of foundation, the height of the building under construction, the level of foundation of neighboring buildings, as well as the budget of the investment. In order to limit soil displacement and deformation as a result of deep excavation, various support systems are used. The authors of this paper present recommendations for the implementation of a deep excavation in the form an innovative system for supporting the walls of existing buildings and for monitoring them, which is especially important from the point of view of the engineers responsible for the construction of the object. The article uses a method that includes the following elements:  
* collecting information on the implementation of infill buildings and the revitalization of historic buildings with the use of facade walls in the vicinity of deep excavations;
* interpretation and synthesis of collected information on the basis of literature and the authors' own design experience related to the applied protection and monitoring systems. Methodology for Determining the Impact of Deep Excavation on Existing Buildings, the Designing of Their Protection, and the Monitoring of Their Technical Condition  
When designing buildings that require a deep excavation in the surrounding neighborhood of existing urban housing, it is necessary to estimate the range of the excavation impact zone, as well as to determine which buildings are located in this zone. For these buildings, expert opinions regarding the technical condition of their structures should be made. This will enable the possibility of transferring additional loads by the structure of these buildings (due to the anticipated uneven ground movement in the area of their foundation) to be determined. The expert opinions should also define the permissible displacements for these buildings. There are many methods in the literature of determining ground movements. Some of these methods are empirical and include all the interactions involved in the erection of a building [7, 8], wheras others only describe a specific aspect in which individual interactions combine [9, 10, 11]. Different approach represents numerical methods which concern the displacement-induced damages to existing structures located in the vicinity of excavation [12, 13, 14]. Most recently design methodologies were proposed to estimate the damage to buildings adjacent to deep excavations using probabilistic or semi probabilistic analyses [15, 16, 17, 18]. The measures of the displacements of buildings that are adjacent to the construction of deep excavations include tilts, deflections, and cracks of structural elements [19]. The value of the vertical displacements of the terrain surface and the shape of the settling basin depend primarily on the type of used excavation casing and the type of ground foundation. The range of impact of the excavations depends on the deformability of the soil, the depth of the excavations, the dimensions of the plan of the excavations, the possible presence of groundwater and the stiffness of the excavation casing.