Construction work on buildings covered by the revitalization program of historic urban development represents a special type of construction project in which, in the execution phase, difficult technical situations and other risk sources are being encountered. An important source of risk is the necessity to preserve a part of the historic substance, which results, among others, from the recommendations of the conservator, legal regulations or from the vision of the architect/investor. The risk is also associated with difficulties and complications in construction works resulting from the location of these objects in dense urban development. The aim of the article is to identify risk factors and reactions of contractors, i.e. applied risk management methods and techniques, based on the example of a complex of buildings constructed in the historic district of Krakow. The elimination of sources of risk, especially of a technical nature, requires the construction management to be highly skilled and experienced, to carefully prepare the construction work and to design additional solutions to ensure safety at work. The experience gained may serve as a basis for risk analysis and identification during the implementation of projects involving the use of an existing building and historic substance in areas subject to revitalization programs.
In Poland, it often happens that construction objects are subject to demolition work for different reasons. Demolition, according the Construction Law, is defined as a type of construction works and, as such, represents a particular type of construction project. As in other construction projects, a very important phase, in addition to execution of the works, is to prepare, design and plan demolition works. Some demolition activities are covered by appropriate regulations and can be described as typical. On the other hand the technical side of demolition works depends on many factors such as: the type of building, its age, technical condition, type of construction, etc. This article covers the analysis of the stages and tasks in the preparatory phase of the building demolition. This work will also present a description of the tasks carried out during the demolition works based on the example of a historic tenement house located in Krakow. This analysis aims to identify implementation problems and sources of risk that may occur during this type of construction work.
The aim of the article is to analyze existing foreign experiences presented in the literature in the field of estimating demolition waste and their applicability in Poland condition. Using the case study method for more than a dozen objects, the authors prove the necessity to verify the suitability of the proposed models in relation to regional conditions (e.g. climatic conditions, local technologies, etc.). The amount of concrete waste from demolition of objects made in the analyzed technology is characterized by a low coefficient of variation, especially in the case of public facilities and is only 10%. However, in the case of residential buildings, the volatility was 16,7%. The calculated average index of concrete waste was compared with the two literature models. The results obtained differ from the values obtained from the models. Based on an analysis of the advantages and disadvantages of the selected models and their assumptions, a proposal has been formulated for the development of an effective tool for estimating demolition waste taking into account regional specific conditions together with the concept of sustainable construction. The focus was on waste from demolition of concrete objects.