Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 172 (2017) 247 – 255 Modern Building Materials, Structures and Techniques, MBMST 2016 Inspection of public buildings based on risk assessment Pēteris Druķisa*, Līga Gailea, Leonīds Pakrastiņša a Kaļķu Street 1, Riga, Latvia Riga Technical University, Insitute of Structural Engineering and Reconstruction *Corresponding author: peteris.drukis@gmail.com, +371 29233300 Abstract Safety of public buildings has become an important issue for authorities after collapse of shopping centre in Riga, at 21.11.2013, where 54 people were killed Safety of building is the practice of designing, constructing, operating, maintaining and removing buildings in ways that no one has deteriorated health, suffered injuries or died due to the use of the building There are a lot of rating systems for sustainable building [1] in the worldwide, but there no such effective systems for rating of buildings according to their safety This paper proposed a risk-based assessment system of public buildings with target to classify these in common way The specific challenges of using such assessment for control purposes during of operation public buildings are highlighted in the work There are also the first results of practical implementation of this method in Latvia Based on the risk assessment there are also a new interactive approach for reporting of results for users of public buildings and stakeholders The outcome of this research is accordingly a performance assessment tool that analyse the effect of risk factors to the safety of public buildings © by Elsevier Ltd This is an openLtd access article under the CC BY-NC-ND license © 2017 2016Published The Authors Published by Elsevier (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of MBMST 2016 Peer-review under responsibility of the organizing committee of MBMST 2016 Keywords: building inspections, public buildings, safety, assessment of safety, consequence class, risk factor, data reporting Introduction Existing buildings in operation, if properly operated, are considered to be safe for people Even these buildings are more than hundred year old, or so call heritage buildings [2] However, due to technological progress, as well as changes in laws and regulations related to the integration in the European Union, the roles for both employees and maintenance staff regarding the use of public buildings are becoming more and more sophisticated Existing buildings are designed according to the safety requirements of the decade they were built, however, today the requirements of the respective safety level are higher New requirements have been introduced, the provision of which requires proper attention and resources of the owner [3], and nowadays the building safety requires special attention [4] Some buildings depending on their time of construction in Latvia have different safety levels Taking into consideration that users of the building expect the same level of safety there can be situations leading to severe 1877-7058 © 2017 Published by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of MBMST 2016 doi:10.1016/j.proeng.2017.02.106 248 Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 accidents In Latvia there are buildings in operation, most of which were built more than 20 years ago in accordance with the Soviet building norms (SNiP) [5] Besides, there are also buildings which were built before 2010 in accordance with national building norms (LBN) [6] and there are also buildings built during the last years already in accordance with the European Union's construction standards or Eurocodes (EC) [7] Expectancy of human life is increasing and therefore it is especially important to assure the accessibility of buildings for the elderly people, as well as for disabled people or people with other health problems [8] Earlier a lot of hygiene, health and environmental requirements, as well as energy economy [9] and the sustainable use of resources considerations were ignored, which shall be taken into account nowadays when making upgrades for existing buildings Furthermore, the operational duration of the building is longer than life-time of any other system and equipment in the building, which means that the solutions of the building, their operation and safety lag behind up-to-date technologies If the condition of existing buildings will not be improved in accordance with contemporary requirements and safety level, the number of accidents may rise The following technical and social factors may accelerate the occurrence of accidents: x x x x x depreciation of load-bearing structures; constructing engineering and networks in old buildings; incorporation of different new materials and construction products in an inappropriate manner; increase in the number of the elderly and disabled persons, and integration of disabled people into society; willingness to use the EU structural funds in an inappropriate manner Taking into consideration the above-mentioned circumstances, the Parliament of Latvia in the Construction Law [10], Article 21, Clause has laid down the obligation of the owner of the building to provide proper maintenance of the building and its components during the operation thereof in the condition compliant with the essential requirements defined in the Construction Law, Article 9, Clause These essential requirements are identical to the basic requirements defined by the European Parliament and EU Council Regulation Nr.305/2011 [11]: x x x x x x x mechanical resistance and stability; safety in case of fire; hygiene, health and the environment; safety and accessibility in use; protection against noise; energy economy and heat retention; sustainable use of natural resources In order to meet the above-stated requirements, the responsibility of the building owner is to make sure that: x x x x the building is safe for its users and building maintenance staff, the building is being properly maintained; essential risk factors are evaluated during the use of the building; relevant improvement measures are carried out in accordance with the results of technical surveys The Parliament of Latvia in order to assure that the owner of the building complies with the mandatory obligations stated in the Construction Law has entitled building inspectors to monitor the operational compliance of buildings with the regulatory requirements The control in public buildings *, which are expected to admit more than 100 people at the same time, paying special attention to the safety of the building, is performed by specially prepared building inspectors [10] * Public building is building, where people receive a variety of services linked to education, recreation, shopping, work and a range of other social and economic matters [12] Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 This publication shows the principles of building inspections based on risk assessment approach and the first results which have been obtained by carrying out inspections of public buildings in 2015 with the purpose to identify their compliance with the essential requirements stated in the Construction Law [10] Materials and Methods 2.1 General The purpose of the safety inspection for public buildings based on risk assessment is to determine the level of compliance with the essential (regulatory) requirements of the public building identifying risk factors and their impact on the operational safety of the building in order to provide an assessment of the safety of the building and its future operational alternatives As a result of each inspected building the official inspection report is prepared, which contains the assessment of a building performed by the inspector regarding its compliance with such essential requirements as mechanical resistance and stability, fire-safety, hygiene, health and environmental protection, as well as safety and accessibility in use of the building Such essential requirements as protection against noise, energy economy and sustainable use of resources are not included in the scope of the inspection 2.2 Mechanical resistance and stability of the building When performing the inspection of mechanical strength and stability of the building, general visual inspection of the building and its premises is carried out inspecting the structures of foundations, exterior walls, load-bearing structures and the roof structure Depending on the state of load-bearing structures of buildings [13-15] the following mechanical strength and stability requirements are assessed: x x x x ability of load-bearing structures to provide the nominal of designed load-bearing capacity; deformation exceeding the allowable limits ; collapse of the building or its separate parts; damages of other parts, joints, fittings or installed equipment of the building due to the deformation of the load-bearing structures When assessing mechanical strength and stability of a building, the statement or conclusion contains assessment thereof according to Table No.1 Table Risk factors of the mechanical resistance and stability of the building Risk factor Results of inspection RF1 Minor breaches of mechanical resistance and stability requirements have been identified constituting no significant risk for health and/or life or environment of users of the building RF2 Breaches of mechanical resistance and stability requirements have been identified constituting significant risk for health and/or life or environment of users of the building RF3 Such breaches of mechanical resistance and stability requirements have been identified constituting impermissible risk for health and/or life or environment of users of the building 2.3 Safety of the building in case of fire When performing the inspection of safety of the building in case of fire, general visual inspection of the building and its premises is carried out inspecting the compliance of the premises, structures and separate elements of the building with the fire-safety requirements Depending on the type of usage of the building [16] the following firesafety requirements are assessed: 249 250 Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 x x x x x whether the load-bearing capacity of the structures can be maintained in case of fire; whether the generation and spread of fire and smoke within the building is limited; whether the spread of fire to neighbouring buildings is limited; whether occupants/ residents can leave the building or be rescued by other means whether the safety of rescue teams is assured When assessing safety of the building in case of fire, the statement or conclusion contains assessment thereof according to Table No.2 Table Risk factors of the safety of the building in case of fire Risk factor Results of inspection RF1 Minor breaches of safety requirements of the building in case of fire have been identified constituting no significant risk for health and/or life or environment of users of the building RF2 Breaches of safety requirements of the building in case of fire have been identified constituting significant risk for health and/or life or environment of users of the building RF3 Such breaches of safety requirements of the building in case of fire have been identified constituting impermissible risk for health and/or life or environment of users of the building 2.4 Hygiene, health and the environment of the building The greatest majority of people carry on 80–90% of their lives inside buildings, which must satisfy the objective and subjective requests linked to vital functions of the occupants In existing and future buildings there will be an increasing focus on energy uses and indoor environmental quality [17] When performing the inspection of the compliance with the hygiene, health and the environment requirements of the building, general visual inspection of the interior and exterior of the building is carried out assessing the potential threats to the health and safety for the users of the building, as well as for the environment Depending on the type of usage of the building it is assessed whether there are no emissions of dangerous substances or toxic gases, faulty release of wastewater, solid or liquid waste or faulty disposal of waste causing pollution, as well as presence of dampness on the structures of the building and “sick building syndrome” [18] When assessing the compliance with the hygiene, health and the environment requirements of the building, the statement or conclusion contains assessment thereof according to Table No.3 Table Risk factors of hygiene, health and the environment of the building Risk factor Results of inspection RF1 Minor breaches of hygiene, health and the environment requirements of the building have been identified constituting no significant risk for health and/or life or environment of users of the building RF2 Breaches of hygiene, health and the environment requirements of the building have been identified constituting significant risk for health and/or life or environment of users of the building RF3 Such breaches of hygiene, health and the environment requirements of the building have been identified constituting impermissible risk for health and/or life or environment of users of the building 2.5 Safety and accessibility in use of the building When performing the inspection of the compliance with the safety and accessibility in use requirements of the building, general visual inspection of the building is carried out assessing the potential threats to the health and safety for the users of the building Depending on the type of usage of the building and time of its construction or reconstruction, the following requirements are assessed: Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 x whether unacceptable risks of accidents or damage in service or in operation such as slipping, falling, collision, burns, electrocution, injury from explosion are not present for users of the building; x whether the building is accessible for disabled persons [19] When assessing the compliance with the requirements of safety and accessibility in use of the building, the statement or conclusion contains assessment thereof according to Table No.4 Table Risk factors of safety and accessibility in use of the building Risk factor Results of inspection RF1 Minor breaches of requirements of safety and accessibility in use of the building have been identified constituting no significant risk for health and/or life or environment of users of the building RF2 Breaches of requirements of safety and accessibility in use of the building have been identified constituting significant risk for health and/or life or environment of users of the building RF3 Such breaches of requirements of safety and accessibility in use of the building have been identified constituting impermissible risk for health and/or life or environment of users of the building 2.6 Principle of risk assessment The essence of inspection methodology is to provide a risk assessment regarding each of the essential requirements in the scale from to 3, where is no comments (compliant, safe), but is the unacceptable risk (noncompliant, dangerous) The risk assessment is performed in accordance with special procedures to conclude whether the identified damages cause significant or unacceptable risk to users of the building, or whether risks are reasonably low, based on: x x category of building consequence class according Eurocodes [20]; risk factor of each of the essential requirements Principle of risk assessment described in Figure Fig Principle of risk evaluation Each inspection results in the statement of assessment based on the risk evaluation The results of inspection are stated using the following scale of assessment: “0” – Excellent condition/entirely safe No defects have been identified No action is necessary “1” – Good condition/safe Minor defects constituting no threats to the safety of the building have been identified Take care during of maintenance actions “2” – Bad condition/safety shall be improved Defects constituting threats to the safety of the building have been identified They should be repaired in appropriate way “3” – Dangerous condition/unsafe Defects constituting significant threats to the safety of the building have been identified Operation of the building or the part thereof shall be instantly stopped 251 252 Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 Results 3.1 Scope of inspection and number of assessment In Latvia in accordance with the data of the State Land Service there are 391 522 buildings registered in total, of which 359 897 buildings or 25,9% are residential buildings, 005 355 buildings or 72,2% are non-residential buildings and 26 270 buildings or 1,9% are engineering facilities Public buildings are sub-classified under the group of non-residential buildings taking into consideration their main types of usage The existing classification system does not foresee to identify separately which public buildings are those expected to admit more than 100 people at the same time Therefore for inspection needs there were special selection of data, based on the area of each public building and assuming that 100 people need definite minimum useful area Depending on the type of usage it is defined for each group of buildings separately Table No.5 shows the results of classification Table Number of public buildings in Latvia designed to admit more than 100 people (Total 7252) Classification Code Main type of usage Number of public buildings Classification Code Main type of usage Number of public buildings 121 Hotel buildings 525 1263 Schools, universities and buildings for scientific research 1100 1220 Office buildings 1602 1264 Hospitals or other health care buildings 461 1230 Wholesale and retail trade buildings 873 1265 Sports facilities buildings 338 1241 Communication buildings, stations, terminals and associated buildings 174 1272 Religious (cult) buildings 859 1261 Public entertainment buildings 625 1273 Historical buildings 39 1262 Museums and libraries 105 1274 Other buildings 551 During of 2015 the operational safety inspections were performed in 623 public buildings designed to admit more than 100 people or 22.4% of all respective buildings in Latvia The scope of data is sufficiently representative in order to draw conclusions on the common trends regarding the safety of public buildings in Latvia The scope of inspection by types of usage of buildings are shown in Table No Table Number of inspected public buildings Classification Code Number of inspected buildings % of inspected buildings total number Classification Code Number of inspected buildings % of inspected buildings total number 121 127 24,2 1263 766 69.6 1220 215 13,4 1264 117 25.4 1230 249 28,5 1265 64 18.9 1241 27 15,5 1272 20 2.3 1261 0,3 1273 2.6 1262 18 17,1 1274 17 3.1 Total 1623 22.4 3.2 Inspection results Performing inspections based on the risk assessment the following results were obtained (see Table No.7) 253 Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 Table Results of public buildings inspection Classification Code 121 1220 1230 1241 1261 1262 No of inspected buildings Risks assessment result % of inspected buildings 115 0-1 90,2 12 2-3 9,8 186 0-1 85,7 29 2-3 14,3 238 0-1 91,2 21 2-3 8,8 24 0-1 88,9 2-3 11,1 0-1 100 2-3 18 0-1 100 2-3 Classification Code 1263 1264 1265 1272 1273 1274 Total No of inspected buildings Risks assessment result % of inspected buildings 687 0-1 89,7 79 2-3 10,3 99 0-1 85,0 18 2-3 15,0 57 0-1 88,9 2-3 11,1 16 0-1 80,0 2-3 20,0 0-1 100 2-3 15 0-1 88,2 2-3 11,8 1455 0-1 89,3 175 2-3 10,7 3.3 Inspection results for public information It is important to inform the society about the safety of the public building For this purpose the interactive map has been specially designed where all the inspections performed are reflected using the symbols of traffic lights Fig An informative traffic light Fig An interactive map to show the results of assessment (https://www.google.com/maps/d/viewer?mid=zvz8klVSI8zA.kDknNWOdGSXk) 254 Pēteris Druķis et al / Procedia Engineering 172 (2017) 247 – 255 An interactive map is based on “Google Map” and allow for users to interactively read the details of the inspections carried out for the specific building, is it safe and where is located There are more than 15 000 unique views during of last months A map can be drawn in and out, thus obtaining accurate information on the location of the building Also information about problematic essential requirement, level of risk and location in building are available Conclusions and discussion Considering the development of legislation in field of European construction and buildings there will be more and more challenges to improve the performance of existing building for nowadays needs The key point of this research is to provide the inspection method for assessment of existing buildings, where whole essential safety aspects have been assessed in common way and in the same time Method should be time efficient, simple for use, easy for reporting and clear for society and stakeholders There are a huge numbers of different inspection methods for safety of buildings [1; 21-28], but they are either very complicated, or time consuming or not cover all safety aspects (essential requirements) The method described complies with requirements set out above and that is novelty of this method compared with existing methods For next stage there are necessary to improve common guidelines for estimation of risk factors for specified essential 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Principle of risk assessment described in Figure Fig Principle of risk evaluation Each inspection results in the statement of assessment based on the risk evaluation The results of inspection are... draw conclusions on the common trends regarding the safety of public buildings in Latvia The scope of inspection by types of usage of buildings are shown in Table No Table Number of inspected public. .. 255 This publication shows the principles of building inspections based on risk assessment approach and the first results which have been obtained by carrying out inspections of public buildings