H-frame and large-panel – technologies for the construction of multi-family buildings in the second half of the 20th century

The H-frame and the large-panel are two competitive technologies for construction of multi-family buildings, that were used in Poland in the second half of the 20th century. Both are based on the use of prefabricated and repeatable elements that make the construction of the building process much faster and less complicated than other technologies. The need to speed up the construction process appeared in Poland after the end of World War II, when the vast majority of the population was deprived of their homes because of war damages. Social policy of the Polish People’s Republic was based, among others, on the rapid restoration and provision of housing resources for society. Prefabricated technologies were used to achieve this goal. What is the difference between large-panel buildings and H-frame buildings?

H-frame

The H-frame technology is based on creating the structure of the object that consists of a prefabricated reinforced concrete frame, resembling the stretched letter H.

PICTURE 1. H-FRAME CONSTRUCTION IN MULTI-FAMILY BUILDINGS (ELEMENTS: 1 – POLE, 2 – BOLT, 3 – COLUMN CONNECTIONS, 4 – BOLT CONNECTIONS, 5 – INTERMEDIATE BOLT)

Source: http://www.relaiscdo.eu/budownictwo/budynki-zelbetowe-prefabrykowane-cz-1 (access: 15.07.2020)

The reinforced concrete skeleton is the supporting structure of the building, which is then filled with bricks or hollow bricks. Visible elements of the structure (columns, beams) are a distinctive element, but also a main disadvantage of apartments in such buildings. The characteristic feature of buildings constructed in this technology is lack of load-bearing walls inside the apartments, which is an invaluable advantage that enables any arrangements of their interiors. Other significant advantages of construction in this technology are: high durability, good acoustics and thermal insulation. It is also worth to mention that the current trends in development constructions refer to the H-frame technology. Its contemporary continuation can be seen in a variant of the monolithic technology, in which a reinforced concrete skeleton structure is used on the construction site.

LARGE-PANEL

The construction based on the technology of large-panel was based on the assumption that the buildings were erected from ready-made concrete prefabricates. The individual concrete elements were manufactured in the so-called ‘house factories’ and then transported to the construction site. In large-panel systems, all elements, such as external walls, ceilings, as well as partition walls, load-beating walls, stairs and elevation shafts, were produced. Compared to the H-frame, the large-panel is characterized by low quality and imprecise workmanship. Leaks at the joints of the panels also have an impact on problems with thermal insulation or moisture in buildings. The durability of large-panel buildings at the time of their construction was estimated as 40 – 50 years.

PICTURE 2. CONSTRUCTION OF A MULTI-FAMILY BUILDING IN LARGE-PANEL TECHNOLOGY

Source: http://www.administrator24.info/artykul/id5106,wielka-plyta-do-modernizacji (access: 15.07.2020)

The interiors of apartments in large-panel buildings are difficult to arrange because of the load-bearing walls that cannot be demolished. Considering that apartments in large-panel buildings were characterized by a large number of small, dark and low rooms, the lack of the possibility of rearranging their interiors may effectively discourage potential buyers on the secondary market from choosing such an apartment. A characteristic phenomenon associated with large-panel buildings is also the deterioration of the quality of newly erected buildings over time. Increasingly meticulous maximization of construction savings meant that at the end of the 20th century, apartments with dark kitchens (without access to daylight) were build, worse-quality finishing materials were chosen (e.g. parquet was abandoned in favour of PVC tiles, and in the following years it was the standard to hand over flats for use without finished floors) and the degree of furnishing of apartments had been increasingly limited. This means that in case of large-panel buildings, there are large differences in the quality and standard of buildings depending on the year of construction.

Summary

Buildings constructed in the H-frame technology are much more durable, easier to arrange (e.g. during renovation) and cheaper to operate, compared to large-panel buildings. Load-bearing walls occurring in the interiors of narrow and low apartments in large-panel buildings make it impossible to adjust the apartment layout to your own needs. Problems with thermal insulation of large-panel buildings mean that their residents have to bear much higher costs of heating their own premises. It is also worth to mention that complexes of buildings constructed in both technologies even until the 1980’s did not provide the needs related to private transport, which is widespread nowadays. This problem concerns the insufficient number of parking spaces for residents in the immediate vicinity. The fact that the surrounding area has been already intensively developed makes it difficult to designate areas for the location of new parking lots. Increased traffic is also associated with the problem of narrow residential access roads, on which parking cars additionally hinder the movement for both pedestrians and drivers. However, it is worth noting that the greatest advantage of housing estates built in the discussed technologies is their location. When the buildings were constructed, their location did not seem attractive. These were often areas with no necessary infrastructure or service facilities for residents. However, now their spatial context and location have significantly changed. The spatial development of cities has resulted in the fact that, over several decades, the housing estates constructed with the use of prefabricated technologies have gained a good location in the urban space. These estates are well-connected to the city center, with extensive local infrastructure and service and commercial facilities, which may constitute a competitive advantage over new development investments located on the city outskirts.

Barbara Mariańska
Maintenance and Development Specialist