Buildings constructed in the 1960-s
In these years, the most common type of building was the so called Khrushchovka – the buildings constructed in the USSR in Khrushchov’s time. Among them, the buildings were constructed according to serial design projects K-7, 335, 480, 464, 438, 447.
Main characteristics. The standard Khrushchovka buildings include panel, brick and large-block buildings. Most of them are 5-storied. We already mentioned that 5 floors was the maximum height for a building not requiring an elevator, according to the standard. Sometimes, Khrushchovkas have 3 or 4 floors.
The most popular are panel Khrushchovkas (Figure 1). They became popular due to the high speed of construction from prefabricated reinforced concrete panels. As a rule, these buildings have low heat insulation of the outer walls and poor soundproofing inside the building.
Figure 1 – 5-storied panel Khrushchovka
Brick Khrushchovkas were often constructed in cities that had no local house-building factories. Calcium-silicate bricks and prefabricated reinforced concrete products (floor slabs, balconies, bridges, stair flights) were often used for the construction of such buildings.
Wooden windows.
Khrushchovkas were raised to a new (though quite average) level provision with comfortable housing. All Khrushchovkas have district heating, cold water supply and sewage. A bath is a mandatory element of the bathroom. In most “khrushchovka” projects, the bathroom is combined with the toilet. The gasification of the cities enabled Khrushchovka kitchens to have gas stoves. In the absence of gas supply, kitchens in Khrushchovkas were equipped with wood-fired stoves, and in the case of powerful electrical networks,with electrical stoves. Hot water supply can be of the district type, but often it is non-existent. In this case, gas-fired water heaters were installed in the apartments, usually in the kitchens. In the absence of gas supply, wood-fired water heaters were used.
The floor slabs in Khrushchovkas are made of prefabricated reinforced concrete panels precisely because they had to be inflammable.
Energy saving measures. The construction speed of Khrushchovkas was very high, and this often lowered the quality of construction. The panel Khrushchovkas were intended to have either a 25 or 50 year service life. The brick buildings have a service life of 100-150 years, but due to the low quality of construction they have already lost any durability properties of the bearing structures and building envelope. That is why cold walls often require additional heat insulation with any preliminary capital renovation (or reconstruction).
Quite often, there is a special built-in storage for food products under the kitchen window of brick Khrushchovkas (Figure 2). The thickness of the outer wall in this storage is usually half a brick. In some buildings, this wall has an outer opening which used to be for fresh air ventilation and it was necessary to ensure the proper functioning of the gas stove. In the cold season of the year, the storage functioned as the fridge. But today it is a strong thermal bridge and requires not only façade heat insulation but also additional internal heat insulation.
Figure 2 – 5-storied brick "khrushchovka"
In addition, the wooden window structures also require mass replacement with modern plastic windows. This also applies to the entrance doors. Khrushchovkas not only have cold floors but also cold ceilings, therefore the floor slabs are also subject to heat insulation. The engineering networks, even despite periodical repairs, are almost completely worn out and require capital renovation and mandatory insulation of the heating pipes and hot water supply (if any) pipes. As gas-fired water heating systems were very common at the time of construction, it is expedient to install modern gas meters.
Therefore, the recommended measures include almost all:
- Roof insulation;
- Heat insulation of the building envelope or Insulation of attic floor, combined floor structure or pitched roof with polyurethane foam;
- Insulation of portions of vertical surfaces and constructional wall and roof connections with polyurethane foam (to remove numerous thermal bridges);
- Partial or complete reconstruction of the roofing before insulating the attic floor;
- Insulation of the floor or basement floor;
- Heat insulation of basements, foundations and pedestals;
- Replacement of old windows with modern plastic or metal-plastic windows;
- Heat insulation or replacement of entrance doors, arrangement of a single or double ante-room, installation of door closers (if there is space for a double ante-room);
- Installation of reflectors (screens) behind radiators;
- Insulation of pipelines in the heating systems;
- Insulation of pipelines in the hot water supply (HWS) system;
- Installation of manual thermostatic valves on radiators with preliminary adjustment (balancing of the double-pipe heating system);
- Installation of automated heat energy supply unit (individual heat substation (IHS) with weather-based control); installation of automated HW supply unit; replacement of the high-speed heat exchanger in an HWS system with a plate heat exchanger (depending on the specificities of the connection to the heat network);
- Replacement of indoor lighting incandescent lamps (also in common areas) with modern energy efficient lamps;
- Installation of astro timers[1] in the lighting system for common areas;
- Installation of motion sensors in the lighting system for common areas;
- Installation of gas meters. Optimization of work of the building internal gas supply system.
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[1]Astro timer is a device for precise automatic turn on and turn off for the lighting and other electricity consumers at the time of sunrise and sunset, with daily adjustment during the year. In the process of astro timer setup, GPS coordinates are input, as well as current date and time are set.