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In the past 2016 228,586 new property owners are registered with the Registry Agency. However, the number of deals with new homes is only a small part of this impressive figure. For most newcomers, among other indicators determining the profitability of the purchase, with particular weight in choosing a home should consider the remaining life of the building. This concept is relative and is a combination of many factors. The most significant of them are structural security of the building, moral and physical depreciation, maintenance costs, opportunities for reconstruction and increase of the useful built-up area.

Functional reconstructions

The first criterion for determining the residual life of a structure is its functionality and the possibilities for changing its purpose. In recent years, the economic interests of owners and investors have created a wave of restructuring. Modern business needs turn semi-underground premises into shops, former factories - into shared workspaces, apartments - into restaurants and entertainment. Thus, a large number of premises and entire buildings with reduced or completely exhausted resources, according to their original purpose, are put back into operation.

This sustainable trend is possible thanks to the application of original architectural solutions, significantly increasing the residual life for, at first glance, completely worn out physically and morally buildings and premises. Particularly flexible and modern, it is found on both large and small scales. Allowing many small businesses to save on high rents or capital investments for new construction, while realizing environmental savings through full use of the already built building stock.

Constructive security

As a mandatory condition for this to happen is the most important indicator determining the residual life of a structure, namely - its structural safety. It is quite logical that the global trend of this security is constantly increasing. Thanks to the rapid development and application of new technologies for design and implementation, the increasing requirements for the seismic safety of buildings, the intensified international exchange of knowledge and normative documents are constantly increasing this indicator. These factors also guarantee a longer and trouble-free life of the structure. In addition to increased security, the development of construction technologies allows the realization of bolder. architectural solutions even in earthquake-prone areas, as well as increasing the number of storeys of buildings.

Quality of construction

The widespread claim of higher quality construction before the 90s of the last century is greatly exaggerated. The main argument in support of this thesis is the inability of most of the old buildings to meet the modern, mandatory for new buildings, design requirements. Inspections of such old buildings very often reveal serious discrepancies between the norms in force at that time and the actual implementation. There are many buildings that were built without the necessary construction documentation, but subsequently legalized only on the basis of architectural photography. The time check often covers only the quality of the waterproofing of the foundation, the finishing works, the laying of the foundation and the functionality of the premises and the adjacent areas around the building. Most of the old building stock could actually exist for tens and hundreds of years without the need for structural repairs, but not only with quality funding, lack of seismic impacts and bends. After a subsequent increase in earthquakes, occurring on the territory of Bulgaria in the last 100 years, are completely or partially destroyed cities, tens of thousands of neighboring buildings and not a small number of human casualties.

                                          The Catholic Hospital in Plovdiv after the Chirpan earthquake

Despite the better modern norms and methods of design, both in the past and today there are no examples of practice with serious violations. Most often they are in the implementation phase of projects. The most common defects that reduce the life and safety of a building structure are:

• poorly vibrated concrete, insufficient coverage of the reinforcement

 • insufficient reinforcement and sagging of horizontal elements

• excessive reinforcement of horizontal elements

• incorrect decomposition of the reinforcement during installation

• displacement of the reinforcing skeleton during concreting

• low quality of the used materials

• presence of high humidity in bearing elements

• uneven subsidence of the foundations due to poor foundation or water filtration

Statistics on the causes of accidents in construction

Due to the great variety and different significance of these defects on the security of the building, it is not possible to give an unambiguous answer to the question "how long is the life of a given type of construction". It is more important to pay attention to and analyze to what extent these defects are removable and whether it is profitable.

In many cases, the defects are relatively easy to eliminate with small investments. For example, in case of insufficient reinforcement, composite systems could be applied, the application of which takes hours and significantly increases the security of the whole structure.

Some repair works, such as the addition of underground waterproofing, not only improve the conditions in which the structure is located, but also increase the quality of the living environment. The reduced humidity guarantees better thermal insulation properties of the partition elements, removes the presence of mold and mildew, improves the subjective feeling of clean air.

In other cases, achieving acceptable levels of security and increasing the life of the building are financially unprofitable. Especially when it comes to small buildings in developed urban areas, where the structural indicators allow larger building parameters and there is interest from private investors.

Moral aging

The obsolescence of premises and buildings must also be taken into account in a long-term investment, such as real estate.
For example, prefabricated blocks with a constructive life of over 100 years, such as more than 20% of homes in the country, do not tolerate special options for reconstruction. In foreign practice, projects are implemented that completely change their appearance, energy efficiency and market value. And the premises and buildings must also be taken into account in a long-term investment, such as real estate.

In the most general case, the design life of investments in construction and equipment varies within the following limits:

• improvements of the surrounding space - 20 years.
• life of the buildings - 25 ÷ 60 years.
• their furniture and equipment - 2 ÷ 15 years.

After a certain period of time, the funds needed to repair and renovate the building stock increase dramatically and the investment becomes unprofitable.

You can contact us for assistance in choosing a new, safer home. Making the right, informed decision when buying saves big costs for owners in the future. 

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Author: Dr. Eng. Teodor Todorov