1. Construction works failures 1.1. The essence and main reasons for construction works failures 1.2. History of construction works catastrophes and their main reasons 1.3. Failure aspect in design, execution and maintenance 1.3.1. General information 1.3.2. Design with regard to reliability 1.3.3. Durability of construction works 1.3.4. Control as a factor influencing reliability 1.4. Construction works failures as the subject of scientific research 2. The essence of construction works diagnosis 2.1. The focus of construction works diagnostics 2.2. Diagnostics in the case of construction work failure 2.3. General assessment of existing structures in accordance with ISO 13822 3. Detailed assessment - activities to be undertaken and their characteristics 3.1. Review of documents 3.2. Identification of the structural system and structural damage 3.3. Investigation of surroundings influencing structure performance 3.3.1. Environmental conditions 3.3.2. Subsoil characteristics 3.3.3. Dynamic effects 3.3.4. Seismic and quasi-seismic effects 3.4. Measurement of structural deformations and cracks 3.4.1. Deflection of beams and slabs 3.4.2. Structural displacement 3.4.3. Crack measurement 3.4.4. Strain measurement 3.5. Identification of condition and parameters of structural materials and components 3.5.1. Groups of methods 3.5.2. Visual and organoleptic methods 3.5.3. Laboratory identification of the structural materials parameters using samples from structural members 3.5.4. Destructive methods for concrete strength assessment 3.5.5. Non-destructive methods of estimating strength parameters 3.5.6. Non-destructive methods for assessing structural member condition 3.6. Proof load testing 3.7. Calculations 3.7.1. Calculations focused on proving the suspected reason of failure 3.7.2. Calculations focused on assessment of the safety of damaged structure 3.7.3. Calculations for designing the repairs 4. Structural failures and their reasons 4.1. Introductory information 4.2. Failures resulting from subsoil conditions 4.2.1. Failure due to excessive or non-uniform settlement of parts of the construction work 4.2.2. Faults in foundation works near existing buildings 4.2.3. Change in subsoil conditions during use 4.2.4. Other foundation faults 4.3. Failures of reinforced concrete structures 4.3.1. Errors in design and execution of reinforced concrete members 4.3.2. Crack patterns due to load 4.3.3. Crack patterns due to shrinkage and fluctuations in temperature 4.3.4. Damage due to environmental and operational factors 4.3.5. Specific damage to concrete liquid tanks 4.3.6. Specific damage to concrete silos 4.4. Failures of masonry structures 4.4.1. Failures of masonry walls 4.4.2. Failures of arches and vaults 4.4.3. Damage caused by the environment and the surroundings 4.5. Failures of timber structures