Proposed Methodology For New Regulation And Guidelines On Noise Protection For Buildings And Sound Insulation In Turkey

Transcription

1 Proposed Methodology For New Regulation And Guidelines On Noise Protection For Buildings And Sound Insulation In Turkey Nurgün TAMER BAYAZIT 1 ; Selma KURRA 2 ; Bilge ŞAN ÖZBİLEN 3 ; Ayça ŞENTOP 4 1 Istanbul Technical University, Istanbul 2 db-kes Engineering, Istanbul 3 Istanbul Technical University, Istanbul 4 Istanbul Bilgi University, Istanbul ABSTRACT The draft regulation prepared for the Turkish Ministry of Environment and Urbanization, aims to organize the requirements and enforcement for noise control in buildings. A model describing an ideal framework of a building acoustics regulation was introduced and implemented during preparation of legislative and technical documents. The new regulation covers acoustical design, evaluation of acoustic performance during construction, supervising and certification of acoustic quality, investigating and elaboration of complaints from existing buildings. New rating descriptors and the basic classification scheme for the residential buildings were adopted from COST TU 0901 project, however the acoustic performance of buildings in terms of indoor limits, reverberation times, mechanical noise limits and required insulation values, were evaluated for all types of buildings and indoor spaces according to the criteria assessment model developed in the study. Special concerns were given into consultancy, training and building supervising. A technical document prepared to complement the regulation, describes the implementation process of the regulation and highlights good design practice considering the state-of-art in building sector in Turkey. A "decision- model" for low-rise houses is proposed based on the present data for the building elements. This paper summarizes overall results of the study conducted in Istanbul Technical University. Keywords: Regulation, Sound Insulation, Acoustical Classification, Building acoustics design I-INCE Classification of Subjects Number: INTRODUCTION In the process of ensuring users healthy and comfortable living environment, taking control of noise that has many negative effects such as physiological and psychological disorders and interference with activities is quite important (1). For the protection of buildings against noise and the evaluation of sound insulation performances of buildings, legal requirements differ widely in many countries. To perform common practices, the COST Action TU0901: Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions project had been carried out, in which Turkey participated. The project was completed in 2013 and the results were transferred into the draft standard "ISO / NP (ISO TC 043) - Acoustics - Acoustic Classification Scheme for Dwellings" (2,3). There is no legislation on noise protection and sound insulation in the building scale in Turkey. An overview of the Turkish laws and regulations that exist today shows that the subject of noise had found its way into regulations in various forms and with differing emphases. The Environmental Noise Assessment and Management Regulation can be considered the most comprehensive reference on noise (4). However, it deals with environmental noise issues and only briefly mentions the sound 1 nurgun@itu.edu.tr 2 selmakurra@db-kes.com.tr 3 sanbi@itu.edu.tr 4 ayca.sentop@bilgi.edu.tr 923

2 insulation requirements of buildings (since it is considered a different acoustical discipline). Furthermore, local legal legislations are either insufficient or contradictory to one another. The situation indicates the importance of a new national regulation to settle implementation rules and criteria for sound insulation, measurement, application, acoustical consultancy, material performance declaration and other related topics. In 2014, an attempt for constituting a regulation had been made by the Ministry of Environment and Urbanization in the framework of protection against noise items in Building Materials Regulation Annex 1, Basic Requirements for Construction Works (5). For the preparation of legislation, a protocol had been signed between the Ministry and Istanbul Technical University s Faculty of Architecture. At the end of the project, two drafts were prepared as an appendix in order to facilitate the operation of the regulation: Regulation on Protection against Noise and Sound Insulation in Buildings and "Guideline on Acoustic Design of Buildings, Implementation and Supervision. "The guideline describes the technical applications, principles, and methods mentioned in the proposed regulation. This new regulation settles the limit values and the indexes to be used, along with other requirements for sound insulation. Every building should provide the minimum acoustic performance, but buildings should also be comparable to one another so that one should be able to distinguish an improved performance from others. Therefore, an acoustical classification scheme is used for the new regulation. Prior to preparation of the draft regulation, the detailed investigation was carried out about the national legislative documents referring building noise control, by-laws of the municipalities, the regulations of other countries and the acoustical standards published by EN, ISO, BS, DIN, ÖNORM and ASTM etc was researched. The existing situation in Turkey, regarding the community s reactions to noise, weaknesses of building sector in sound insulation, status of education in building acoustics, the facilities such as acoustic laboratories and the appropriate framework of a regulation for protection buildings against noise, was elaborated. An important input was the results of recent COST TU 0901 action, which aimed to develop a common scheme for descriptors, limit values, and acoustical classifications used throughout Europe. In this paper, the scope of the draft regulation and guidelines prepared by the research team and submitted to the Ministry are summarized. The text of the draft regulation and guideline open to public can be found at reference (6). 2. PRINCIPLES APPLIED IN DEVELOPMENT OF THE REGULATION Development of a regulation against noise for protection of human health and well-being is not easy task since numbers of stakeholders have responsibility in implementations. Close relationship between the environmental noise regulations and the indoor noise regulations can be established, however the latter is generally involved with under the building regulations. The EU Inter Institutional Agreement on Better Law Making, 2011 describes the principles which are applicable also in development of building noise regulations (7). These principles are associated with effectiveness, efficiency, coherence and relevance. The attributes of simplicity, clarity and consistency in drafting of regulation are promoted and the highest transparency of legislative process is required. Development of a noise regulation generally needs to take into account the below aspects of the country (7): A. Institutional approach and facilities; laboratories, research potentials, etc. B. Public concern and complaints from noise, C. Interest of various related sectors and noise control implementations D. Noise issues handled by the local administration (responsibilities) and government attention E. Regulations: Directly or indirectly related to noise, environmental and building regulations, standards, specifications on noise control in buildings F. Education level and need of training for architects, constructors, supervisors etc. G. Status of the housing industry, technological developments and economic growth Generally, proposal of a regulation related to noise, should provide a complete protect those living in buildings from outdoor and indoor noises mostly known as neighborhood noise. It should provide fair warning but also avoid the possibility of wrong understanding. The scope and the main rules or other authorizing procedures should be clearly identified. The responsibilities regarding the enforcements, handling complaints, inspections, warnings, fines or the incentives for improvement work, should be described in the regulation. The draft regulation requiring the expert involvement, should be debated by those who would implement and make enforcements, especially it is 924

3 indispensable to receive the public reactions. Validation of noise regulation is of importance and can be defined as the degree which a regulation succeeds in providing the benefit that it is designed for. Because the invalid regulations without basing on cost/benefit analyses have less applicability and those with the inappropriate limits may not ensure adequate protection or sometimes reduce the effectiveness of solutions. The descriptors for rating insulation and used for limit values, should be selected so as to measure also the physiological impact of low frequency noises in addition to those of broad bands. All of the above mentioned principles were paid attention in the proposed regulation. 3. SCOPE AND CONTENT The aim of the proposed regulation is to determine the rules to be followed in terms of design, construction, operation, and maintenance; in addition, determining how to minimize the adverse effects of noise-exposure, and ensure good hearing and perception conditions, peace, and tranquility (within the realm of the physical and mental health of people) are also taken into account. The draft regulation will be applied at the operation and use phase of all kinds of structures, buildings, facilities, and enterprise used by public institutions and organizations, private entities and real persons. As illustrated in Figure 1, the proposed regulation is intended to operate in four stages: (A) acoustical design stage, (B) construction stage, (C) after construction stage, and (D) assessment of complaints. Figure 1 Structure of the Regulation and operational stages Draft regulation covers the measures to be taken in buildings and indoor spaces for any new structure depending on sensitivity to noise. Environmental noises, neighborhood noise consisting airborne and impact sound and noise of mechanical and electrical systems such as heating, air conditioning, plumbing systems, etc. are all taken into consideration. On the other hand, the draft guideline describes the operation and principles of the proposed regulation. The general content of proposal and draft guideline is illustrated in Figure 2. The draft regulation includes the following chapters, titled as the following: 1. Purpose, Scope, Administrative Basis and Definitions 2. General Principles 3. Noise and Sound Insulation Descriptors to be Used and their Implementation 4. Required Insulation Class in Buildings and Limit Values For Indoor Noise Levels 5. Required sound insulation values in buildings and principles of implementations 6. Control Measures for Mechanical Systems Noise 7. Expertise, Evaluation, Testing and Reporting 8. Control / Assessment / Certification (Insulation Class and Acoustic Quality certification) 9. Expertise, Evaluation of Complaints, Review and Administrative Sanctions 10. Miscellaneous and Final Provisions: Operation and Implementation 925

4 Determination of criteria 4 Design of building elements satisfying the criteria Design (New or Existing Buildings) Figure 2 Acoustical design stages proposed in the regulation (Box with straight line ( ) : Subjects defined in Regulation. Box with dotted line (- - -) : Subject defined in Guidelines ) The draft guideline covers the following subjects: Annotations, flow diagrams and schematic expressions aimed to support the use of the regulation Design principles for buildings in order to ensure the protection against noise, and sound insulation in different scales in settlement, building and place, building material, service systems The theoretical and technical information about the acoustic design of buildings Simple approaches, in case there is no acoustical consultant taking part in a project Typical details of sections and joints of building elements Methods for improving the acoustics of existing buildings Noise control in mechanical and plumbing service systems (in principle) Controls to be applied for the assessment of building acoustics, "Building Acoustic Assessment Report, checklists, and the "Acoustic Quality Certificate" Methods for investigating satisfaction of the residents from insulation Requirements for qualifications of acousticians or acoustic consultancy institutions that will prepare acoustic projects and reports and carry out calculations and modelling for training and certificate programs (discussions about these subjects are still ongoing) Despite the COST project recommending classification schemes only for residential buildings, the proposed regulation includes the classification schemes for all types of buildings, such as educational buildings, office buildings, etc., and the principles that should be implemented to obtain (optional) the acoustic quality certificate. Thus, taking the current practices of the EU countries into consideration, the acoustical performances of buildings are evaluated the criteria of airborne and impact sound insulation of internal and external structural elements, permissible indoor background noise levels, reverberation time, and noise levels resulting from mechanical systems. The qualifications and tasks of the acousticians were also defined, so that an acoustician must prepare acoustical projects for buildings that will receive an acoustic quality certificate, for buildings using different systems and materials (rather than traditional construction systems and materials), for noise sensitive buildings (such as education and health facilities etc.), and for buildings demanding high class insulation. The presence of an acoustic project and control of whether or not measures are taken in the architectural project and during the construction will be evaluated with Building Acoustic Assessment Reports (BAAR). Building Acoustics Assessment Reports (BAAR) I-II-III-IV [related to 926

5 four stages] are illustrated in Figure 3. These reports that should be prepared by the experts, will be submitted to the responsible authority. Figure 3 Building Acoustics Assessment Reports in four stages 4. ACOUSTICAL PERFORMANCE OF BUILDINGS The new regulation obligates the assessment of new and existing buildings according to their acoustical performance. Acoustical performance is a term that comprises of airborne and impact sound insulation of building elements, along with indoor background noise levels, reverberation time and mechanical noise levels. Acoustical performance can be defined as, either for a total building, or for a single unit in the building. According to the regulation, through calculations and measurements, new and existing buildings shall demonstrate that they comply with the minimum requirements, which are given according to room functions. In the long term, the regulation shall be reviewed every three (3) or five (5) years, and revisions can be required (according to results and market adaption). Both the EU/COST TU 0901 action and the subsequent standard ISO/WD propose the use of six (6) classes to rate the sound insulation of buildings (3). The classes range from A to F, with A corresponding to the highest sound insulation level. The classes and corresponding sound insulation values are depicted with a chart. The decision of which class should represent the minimum requirements depends on each country. This project, however, aimed at only residential buildings. The insulation rating descriptors accepted for use, are D nt,w, D 2m,nT,w and L' nt,w indexes applying the adjustment terms of C , C tr, and C I, for the low frequency sounds. For background noise levels indoors and for the mechanical noise levels, the L Aeq and L Fmax are recommended respectively. The new regulation is basically established on the same approach. Building types, other than residential, are also included in the scope. The regulation defines acoustical criteria for residential and educational buildings, health services and rehabilitation centers, offices and administrative buildings, accommodation facilities, dormitories, cultural facilities, commercial facilities, terminals, public buildings, entertainment facilities and sports centers. The minimum performance requirement is specified as class C for new buildings, and D for existing buildings in the short-term use of the 927

6 regulation. In the long term, the regulation shall be reviewed every three (3) or five (5) years, and revisions can be required according to results and market adaption. Due to on-going debates about the social and economical aspects and technical difficulties of including low frequency performances in calculations and measurements, the frequency range is currently accepted as Hz, except in two cases: where the low frequency component of noise is dominant (as in mechanical rooms) or when the acoustical consultant considers to extend the adaptation term including 50 Hz necessary. The regulation specifies the acoustic performance criteria of buildings and principles for selection of the criteria. Acoustic criteria are categorized as: a) indoor background noise level, b) reverberation time (in terms of noise control) c) airborne sound insulation for partitions and facades d) impact sound insulation e) Mechanical noise levels. Methodology to apply in the calculations and selection of the limit values are described in the guide as the following: The acoustic quality class for buildings or independent units within the building will be determined. The maximum permissible indoor background noise levels will be determined according to the selected acoustic quality class in L eq, dba unit Interior background noise levels will be converted to the spectral criterion of Noise Reduction (NR), by means of a chart given in the guideline The reverberation time limit values level will be determined according to the proposed regulation. The guideline also provides information on this subject. Sound insulation criteria will be determined according to the selected acoustic quality class with either the simple or calculation method (Figure 4). The maximum permissible indoor background noise levels for mechanical and electrical systems will be determined according to the selected acoustic quality class in L eq or L Fmax dba units. Figure 4 Determining sound insulation criteria using the calculation (expert method) and simple method (*) According to Regulation, (**) The mentioned table can be found in Regulation (6) or in Tables 1&2 in this paper as an example, (***) The mentioned table can be found in Regulation (6) or in Table 2 in this Paper 4.1 Proposed Simple Method for Determination of Sound Insulation For the purposed regulation, noise sensitivity degrees are defined for all building types. The sensitivity degrees are assigned to typical room functions as; I corresponds to high sensitivity, II to normal sensitivity, and III to low sensitivity against noise. Apart from the sensitivity, each building and room function is also identified according to noisiness, where HN stands for high level of noisiness, MN for moderate noisiness and LN for low level of noisiness. The building and typical 928

7 room functions are input into a chart where both sensitivity and noisiness ratings are given. An example of this table is given in Table 1. Table 1 Sample table of noisiness and sensitivity ratings identified for residential buildings (I: high sensitivity;ii: normal sensitivity; III: low sensitivity; HN: high level of noisiness; MN: moderate noisiness; LN: low level of noisiness) BUILDING FUNCTION Residential Buildings BUILDING ROOM Source Receiver Source Receiver ROOM FUNCTION Noisiness Sensitivity Noisiness Sensitivity Bedrooms MN I Living rooms MN II MN I Kitchen / Bathroom HN II Circulation areas HN III Corridor MN III The categorisation of the buildings and rooms, according to their sensitivity and noisiness, gives 2 parameters with 3 ratings for each one (3 sensitivity + 3 noisiness). The sound insulation requirement between two adjacent rooms can be defined by creating a matrix with these two parameters (3,8). Additionally, a third parameter is the acoustical quality class and expected sound insulation, which should increase toward Class A. This leads to a 3-dimensional array, given in Table 2. Table 2 Airborne sound insulation criteria (min. required insulation) in relation to sensitivity and noisiness, D nt,100, db (D nt,100 =D nt,w +C) Source Room Noisiness Level High Level of Noisiness (HN) L Fmax>65dBA Moderate Noisiness (MN) 65 L Fmax>45 dba Low Level of Noisiness (LN) L Fmax<45 dba Receiver Room Sensitivity Level Acoustical Quality Class A B C D E F I II III I II III I II III A partition between a room with noisiness level MN (moderate noisiness) and a room with sensitivity level I (high sensitivity) should meet 54 db for Class C performance. Required insulation increases with 4 db steps toward Class A. This complies with the value given for partitions between dwellings and other dwellings or rooms in EU/COST TU 0901 (8). The sound insulation requirement between HN (high level of noisiness) and sensitivity level I (high sensitivity) is specified as 60 db for Class C, which also complies with EU/COST TU 0901 requirements for partitions between dwellings and noisy activities. Other combinations are derived by the interpolation of these values (Figure 5). 929

8 (a) Figure 5 Airborne sound insulation values according to classes: (a) Extraction of sound insulation values for class C, (b) Combined chart for acoustical quality classes Considering that the annoyance from impact noises is much higher than the airborne sounds based on the investigations, the criteria for the impact noise insulation are defined regardless of sensitivity. Noisiness of the source room and the targeted acoustical quality class are identified while determining the required impact sound insulation (Table 3). The values are in compliance with EU/COST TU 0901 (8). In order to facilitate determination of required sound insulation, values for most typical room functions are derived from Table 1, 2 and 3. These values are combined in the matrix systems prepared for each building function. A sample matrix is displayed in Table 4 for partitions separating different rooms within the residential buildings. The limits for façade elements are given related to outdoor noise levels and indoor background noise limits (Table 5). Façade reflections are taken in consideration and values are increased 3 db. Table 3 Impact sound insulation criteria (max. acceptable impact noise level) according to noisiness, L ' nt,100, db (L' nt,100 = L' nt,w + C I) Source Room Acoustical Quality Class Noisiness Level A B C D E F HN Vertical MN LN Horizontal (b) Table 4 Airborne sound insulation criteria (min. required insulation) for residential buildings, D nt,100, db Adjacency Acoustical Quality Class Room Room A B C D E F Commercial use Housing unit Common access areas Housing unit Bedroom Bedroom Living room Bedroom Kitchen / Bathroom Bedroom

9 Table 5 Façade sound insulation criteria (min. required insulation) for residential buildings, D 2m,nT,100, db Acoustical Quality Class Indoor Background Noise, L Aeq, db (during the time of usage) (D 2m,nT,100 = D 2m,nT,w + C tr) Outdoor Noise Levels L gag(l den), db > A B C D E F Proposed Methods for Calculation of Sound Insulation The draft guideline gives some example D ntw (C,C tr) values for various types of building elements. It also explains how to achieve D nt,100 values considering the effect of flanking sounds. Acoustical consultants should use a calculation method while architects are encouraged to use a simple method (9) (Figure 6,7). Proposed simple method can only be used in low-buildings, which can be up to 4 floors height; with no central HVAC system and which are designed with conventional construction methods and materials (e.g. masonry, reinforced concrete, brick or aerated concrete block walls, gypsum board interior elements) and only if the building is aimed to have Class C or D acoustical performance. On the other hand, the calculation (expert) method shall be used by an acoustical consultant for large-scale buildings, buildings with central HVAC systems, mixed-use buildings with spaces for commercial and business activities, and in buildings that are designed with innovative materials or construction methods and curtain walls. Figure 6 Design of building elements conforming to criteria 931

10 Figure 7 Examples of building elements and their sound insulation values 4.3 Acoustic Quality Certificate A certificate is prepared for the authentication of the acoustical performance of buildings. This certificate is not obligatory, yet it can provide an important marketing tool and therefore encourage the investors and designers to improve their acoustical design goals. Every new building should at least comply C Class according to the proposed regulation. Further improvement in performance can be documented with the acoustic quality certificate. After completing required inspections and measurements, the building earns the certificate proving the overall acoustical performance. This certificate shows the performance ratings, (A-F), in: 1. Indoor background noise levels, L Aeq 2. Sound insulation of façade elements, D 2m,nT, Sound insulation of partitions - airborne sound, D nt, impact sound, L ' nt, Mechanical noise levels, L eq, L fmax 6. Reverberation time, T The overall acoustic quality equals the minimum of those obtained from the 6 parameters. The certificate format is similar to Building Energy Performance Certificate (Figure 8). This will allow inclusion of acoustical performance as an evaluation topic when the green certification system for Turkey will be ready. 5. CONCLUSION The effective protection of buildings against noise will be carried out by an accurate design of components, correct determination of descriptors, and limit values. The Noise Protection and Sound Insulation in Buildings regulation categorizes acoustical performance of buildings and specifies the limit values in terms of 6 parameters: airborne sound insulation, impact sound insulation, façade sound insulation, indoor background noise, mechanical noise and reverberation time. Every building should comply with the minimum requirements, but introducing acoustical classes and an acoustical quality certificate for efficient noise control in buildings encourages further improvement. For each parameter, the limit values are defined, ranging from A to F. Special attention was paid to compliance with EU/COST TU 0901 during the determination of the proposed class limits. First, buildings were categorized according to their noise sensitivity and noisiness. Later, the sound insulation values were defined according to the combinations of different levels of noisiness and sensitivity. The intervals between the class limits were kept 4 db, as suggested by EU/COST TU Apart from airborne and impact sound insulation, class limits were also defined for indoor background noise, mechanical noise, and reverberation time, and kept mandatory for buildings. 932

11 Further studies and field research are required to evaluate the suggested class limits from the standpoint of applicability. This may lead to some revisions in the future to be based on the cost/benefit analyses. However, the proposed regulation, initiated by the Ministry of Environment and Urbanization, will fill an important gap in Turkish legislation. With Noise Protection and Sound Insulation in Buildings Regulation entering into force, an increased awareness of sound insulation is expected and the buildings, which comply with the regulation, will provide more acoustically comfortable environments. Figure 8 Acoustic quality certificate (adapted from Building Energy Certificate in Turkey) 933

12 REFERENCES 1. World Health Organization-WHO, Occupational and Community Noise, 2001, available: 2. COST Action TU0901 Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions, , available: 3. ISO/WD 19488:2015 (Rev.20 July 2015) Acoustics Acoustic Classification Scheme for Dwellings, 2012, Genève: ISO. 4. Environmental Noise Assessment and Management Regulation. Republic of Turkey Ministry of Environment and Urbanization, available: (in Turkish), 5. Building Materials Regulation, (305/2011/AB), Republic Of Turkey, Ministry Of Environment And Urbanization, available: (in Turkish) 6. Republic Of Turkey, Ministry Of Environment And Urbanization, available: 7. Interinstitutional agreement on better law-making, 2011, available: 8. Rasmussen B. & Machimbarrena M. (editors), COST Action TU0901 Building acoustics throughout Europe. Volume 1: Towards a common framework in building acoustics throughout Europe., DiScript Preimpresion, BB93: Acoustic Design Of Schools - Performance Standards, UK Department for Education, London,