Buildings should correspond to the appointment and provide favorable conditions for activity of the person. The lay-out and volumes of premises of a building, its constructive decisions, the engineering equipment, and also internal and appearance should answer these requirements.
Buildings should have necessary durability, stability, solidity.
Durability and stability of a building is provided with correct designing, and also corresponding calculation of bearing elements: they should maintain loadings arising at operation from a wind, tremors and vibration, loading from a body weight, people, the equipment, snow etc. Solidity of a building is characterised by degree of durability and fire resistance of the basic building designs.
the Durability is the period of service of a building during which it under the influence of an environment and loadings does not lose necessary operational qualities, durability and stability.
The Durability of buildings is defined by service life of the basic constructive elements: the bases, walls, overlappings, floors, coverings. In the buildings having a skeleton, consisting of the columns fastened among themselves, the beams (crossbars) strengthened by additional elements-communications, also from durability of its designs. It depends on resistibility of materials from which designs, to various physical and chemical influences are executed, i.e. From them is also frost resistance, firmness against rotting, corrosion, and also from quality of building and observance of service regulations. Building designs on durability share on three degrees:
- 1st - service life not less than 100 years;
- 2nd - not less than 50;
- 3rd - not less than 20 years.
Fire resistance buildings is characterised by inflammability group (fireproof, trudnosgoraemye, combustible) and a limit of fire resistance of building materials and designs from which the building is erected. The limit of fire resistance of building materials and designs is defined by duration of resistance of designs to fire and heats before loss of durability by them and stability or formations in them of through cracks. Buildings and constructions on fire resistance are subdivided into five degrees which are defined by the minimum limits of fire resistance of the basic building designs and limits of distribution of fire on these designs.
To raise fire resistance of buildings, them divide into parts the fire-prevention barriers, for example deaf brick walls which interfere with distribution of fire from one part of a building in others. Such walls from a fireproof material name fireproof walls. Their installation sites are provided by building norms.
Operational qualities of buildings are defined by structure and the area of premises, their volume, an internal accomplishment, quality of furnish. And also presence of the engineering equipment: lifts, conditioners, sanitary-engineering and electrotechnical devices. Into them enter: systems of heating, water supply, the water drain, refuse chutes, illumination, installation of telephones.
Depending on set of signs: solidities taking into account operational qualities, appointment and the architectural importance, and also fire resistance degree, according to the classification accepted in Building norms ipravilah, residential buildings are subdivided into four classes. Buildings to which increased requirements are shown concern I class, to IV - minimum.