The principle of "cumulative development" is fundamental for the complex process of restorative-reconstructive transformations in the historical city

The article reveals the general principle of ‘cumulative development’ formulated by the author as fundamental for the complex process of restorative- reconstructive transformations in a historical city at all systemic levels - urban planning, volumetric, functional, and socio-economic, to improve the quality of its existing buildings, which vary in degree of historical and architectural value and destruction. This principle should be interpreted as the city's ability to accumulate various historical and modern positive properties, which together contribute to qualitative changes in it. Thanks to this, the historical urban environment retains its formed uniqueness and receives its continuation in the new compensatory development, which determines its development. This principle is implemented through the combined impact of preserving, restoring, renewing, and transforming methods of restorative-reconstructive transformations to improve the quality of the existing urban environment for living, working, and spending free time in it through the simultaneous preservation and enhancement of the primary importance of its historical layout and development and their contextual addition with new elements for the necessary renewals and changes that will ensure its value and integrity and transition to a new higher quality level. This will contribute to its ‘revival’ and continuity - ensuring the temporal continuity of the architecture of existing buildings and spaces, and in no case copying it. The techniques that reveal this principle of transformation are identified and discussed in detail. Recommendations are given on the relevance of using these techniques for the historical urban environment, which varies in historical and architectural value and destruction. They will help to effectively improve the quality of the existing historical urban environment of any degree of historical and architectural value and destruction and transform it into a comfortable place to live, as well as interesting and convenient for visiting.