A TECHNICAL REPORT ON ACOUSTIC GUIDELINES FOR URBAN DESIGNS COMPILED BY: AJAYI MOSUNMOLA K. - ARC/09/7352 AJULO OLUWADUNSIN M. – ARC/09/7354 SUBMITTED TO: THE DEPARTMENT OF ARCHITECTURE SCHOOL OF ENVIRONMENTAL TECHNOLOGY FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF BACHELOR OF TECHNOLOGY (B. TECH) IN ARCHITECTURE JULY, 2014 TABLE OF CONTENT 1.0 2.0 INTRODUCTION 1 1.1 Environmental acoustics 1 1.2 Guidelines 1 1.3 The urban environment and planning 1 1.4 Sectors of the urban environment 2 THE IMPORTANCE OF ACOUSTICS IN ARCHITECTURAL AND URBAN DESIGN 3 3.0 URBAN NOISE- SOURCES AND CONTROL 4 4.0 GENERAL ACOUSTIC GUIDELINES FOR URBAN DESIGN 6 5.0 CASESTUDY- Bowden, South Australia 8 6.0 CONCLUSION 10 7.0 RECOMMENDATION 11 8.0 REFERENCES 12 Acoustic guidelines for urban designs 2014 1.0 INTRODUCTION Acoustics is the science of sound and it is derived from the Greek word akouein which means to hear. One major goal of acoustical engineering is the reduction of unwanted sound otherwise known as noise control. Unwanted sounds have significant impacts on human health and well being thereby necessitating the need for noise control measures within a building and in the environment at large. There are various branches of acoustics depending on its context. Acoustics of the urban environment can be referred to as environmental acoustics. 1.1 Environmental acoustics Environmental acoustics is concerned with the control of noise and vibrations caused by traffic, aircraft, industrial equipments, recreational activities and other noise-generating activities that take place within the urban environment. Environmental noise within urban areas can be controlled by the urban design of the environment and it is achieved by following laid down acoustic guidelines for the planning of an urban area. Good acoustic design takes into account such issues as reverberation time, sound absorption of finish material, echoes, acoustic shadows, sound intimacy, texture and blend and external noise. 1.2 Guidelines A guideline is a statement by which to determine a course or action. A guideline aims to streamline particular processes according to a set of routine or practice. It can also be referred to as an official recommendation indicating how something should be done or what sort of action should be taken in a particular circumstance. 1.3 The urban environment and design An urban environment is characterised by higher population density and vast human features in comparison to the areas surrounding it. An urban environment is the environment of a city; usually characterised by many buildings in a limited amount of space where most living spaces, shopping areas, educational facilities, services, etc are grouped in close proximity. 1 Acoustic guidelines for urban designs 2014 Picture of a typical urban environment showing Ginza area at dusk from Tokyo tower, Tokyo Urban design involves the arrangement and design of buildings, public spaces, transport system, services, and amenities. It is the process of giving form, shape and character to the city. Urban design is concerned with the liveability of neighbourhoods, towns and cities, and contributes to the economy and the sustainability of the natural and built environments. Quality urban design attracts people to visit, live and work, allows businesses to develop and prosper, and considers built and natural systems in an integrated, connected way. It also facilitates vibrant communities by supporting social interaction, activities and events. 1.4 Sectors of the urban environment Various activities are carried out in the urban environment and these activities produce a level of noise and they have their impacts on the urban environment. These activities are grouped into sectors which are: Agricultural sector Commercial sector Industrial sector Residential sector Recreational sector 2 Acoustic guidelines for urban designs 2014 2.0 THE IMPORTANCE OF ACOUSTICS IN ARCHITECTURAL AND URBAN DESIGN Acoustic considerations are necessary for noise control within and outside building spaces. After air and water pollution, according to the World Health Organisation (WHO), noise is considered as the third hazardous environmental pollutant. Noise control is a set of strategies to reduce noise pollution or to reduce the impact of noise whether outdoors or indoors. The main areas of noise control are: transportation noise control, architectural design, urban planning through zoning codes, and occupational noise control. It helps the architect in designing building spaces with appropriate sizes and shapes in order to have lowest possible amount of noise within the building spaces. The knowledge of acoustics helps the urban planner in his designs in order to ensure that related activities which generate similar noise levels are grouped together within the urban setting. For example, buffering residential and industrial buildings with large parks and recreational activities to reduce the impact of noise since recreational activities have intermediate noise levels to the industrial and residential areas. The knowledge of acoustics guides both architects and planners on the choice of finish material in their design as this can either reduce the impact of noise or generate more noise. The knowledge of acoustics helps the planner to design roads with good geometry, bearing in mind the effects of the geometry of a road on the generated noise while in use. 3 Acoustic guidelines for urban designs 2014 URBAN NOISE – SOURCES AND CONTROL 3.0 Noise pollution is a common problem in urban areas of developed and developing countries. Excessive noise pollution can cause hearing impairment, hypertension, heart disease, annoyance as well as sleep disturbance. Road noise and aircraft noise are the most pervasive sources of environmental noise. Social activities can generate noise levels that consistently affect the health of populations residing in or occupying areas, both indoor and outdoor. The major sources of noise in urban environment are listed below. Sources of urban noise Traffic (transportation): Noise generated from roads and aircraft are the major sources of transportation noise in urban areas. These noise can be a function of the source (the car itself), the speed of motion, the surface pavement used for the construction of roads, lack of restrictions where necessary etc. Social activities and recreation: Urban areas are characterized with high population density, this coupled with the social and recreational activities of the urban dwellers can generate noise. Industrial noise: Industries are part of the urban environment and noise is an unavoidable issue in many working industries, such as metal fabrication industries, entertainment industries, etc. Large construction sites: major construction sites can cause significant levels of noise. Construction works include demolition, maintenance, repair, erection, construction of buildings or roads etc. Control of urban noise Transportation noise can be controlled by the roadway design, use of noise barriers, use of speed control measures, good surface pavement selection, flight operation restriction (for aircraft noise), truck restriction, residential sound proofing etc. Noise generated by social activities and recreation can be controlled by zoning the recreational areas away from areas that need quiet like the residential areas. 4 Acoustic guidelines for urban designs 2014 Impacts of industrial noise can also be reduced by using quieter machines, adopting quieter processes, eliminating or substituting processes that generate high level of noise, zoning industrial areas away from residential areas, etc. Noise from large construction sites can be controlled by using quieter equipments and processes and by erecting temporary barriers around machines that generate high level of sounds. 5 Acoustic guidelines for urban designs 2014 4.0 GENERAL ACOUSTIC GUIDELINES FOR URBAN DESIGN Good acoustic planning cannot be left out of an urban environment if it has to be a functional one. In achieving a functional urban environment, some acoustic guidelines have to be put in place to control the noise levels generated by the various activities undertaken within an urban environment. A lot of measures have been put in place to control noise within the urban environment, an example of which is the noise legislation that was established in the UK for control of music noise from public premises, control of noise from commerce, industry and trade, residential noise regulations, vehicle emissions regulations. Where possible, uses should be sited so as to avoid causing noise disturbance, without adjoining residential accommodation having to resort to environmentally expensive solutions, such as sound proofing via non-opening, permanently closed windows, as these usually necessitate mechanical ventilation. On construction sites, noisy activities should be scheduled for less sensitive times, (for example, delay a rock-breaking task to the later morning or afternoon when most residents are out to work) and periods of respite should be provided from noisier works. Where amplified speech or music from shops is to be controlled, each loudspeaker or loudspeaker system to be placed in such a position that, while it is in use, it remains: located entirely inside the shop situated not less than three metres from any public entrance to the shop directed in such a manner that the device does not point towards any wall which contains an external window or entrance to the shop unless the wall is more than 15 metres from the device itself operating at a level that does not exceed 65 dB(LAeq) two metres from the facade. The Commonwealth regulations for aircraft noise are the Air Navigation (Aircraft Noise) Regulations 1984. 6 Acoustic guidelines for urban designs 2014 This acoustic guideline can be achieved by appropriate zoning of the urban environment. Airports should be located away from the urban centre especially from the residential zone. Traffic noise can be controlled by keeping appropriate setbacks between the buildings and the road. Fences which can serve as barriers should also be constructed. Trees and shrubs should be planted which will serve as a buffer in controlling the noise from the roads. Front of buildings should be used for parking to increase the distance from the road to the building. The materials used in the construction of buildings too are very important especially for buildings prone to high level of noise and those along traffic routes. Annoyance created by industrial waste collection can generate a level of noise. To this end, early-morning collections should be restricted to non-residential areas to minimise early morning disturbances. Refuse bins should be located at sites that provide minimal annoyance to residential premises and compaction should be carried out while the vehicle is moving. 7 Acoustic guidelines for urban designs 2014 5.0 CASE STUDY- Bowden, South Australia An urban environment should be designed to protect occupants from existing noise and potential noise sources. The aim is to ensure noise levels are low enough to enable the majority of people to work, relax, read, study, have conversations and sleep without a high level of interference from road, rail and point source noise. Noise sources affecting Bowden include traffic noise from Park Terrace and Port Road, the train and tram lines, and entertainment and commercial developments. Development proposals will be required to meet statutory acoustic standards, as they apply in South Australia. Noise Levels In Bowden, emphasis was laid on the acoustics of the residential environment. Residential development adjacent to arterial road/rail/tram corridors should be designed to achieve the following noise levels with windows and doors closed. Acoustic Guidelines: Development should be designed to maximise the potential for acoustic privacy for building occupants through measures such as: • Siting and orienting the building away from the noise source and/or providing an external area that limits noise levels. 8 Acoustic guidelines for urban designs 2014 • Arrangement of apartments/tenancies within a building to minimise noise transfer between individual apartments/tenancies. • Locating noise sensitive rooms such as bedrooms and private open space areas away from a noise source. • Locating and designing entrances to be sealed and to provide air lock entries to sensitive rooms. • Window location and design through thicker glass or double glazing of windows in recognition of a noise source. • Sloping of roof or flat/parapet design to assist in noise passing overhead rather than penetrating through the roof of the dwelling. • Selecting appropriate construction materials, such as sound-absorbing materials or materials that reduce sound transmission for glazing, external walls, floors, roofs, ceilings and doors. • Use of buildings that serve as a buffer between different uses, e.g. the location of offices between residential and noise generating uses. • Constructing shared walls and floors between apartments/tenancies in a way that minimises the transmission of noise. • Separating openings of adjacent apartments/tenancies by a distance of at least 3.0m. • Use of acoustic barriers/fencing/walls/mounds. A noise assessment of the Bowden site undertaken by Renewal South Australia and provides conceptual treatment recommendations in order to achieve acceptable noise levels. Acoustic treatments are for habitable rooms exposed to a noise source where the angle between the façade and the sources (such as main road) is 90º or less. The treatments generally consist of upgrading the building façade construction. In order to achieve the acoustic guidelines stated in the table above, emphasis should be laid on the material of construction of various elements of the building. 9 Acoustic guidelines for urban designs 2014 6.0 CONCLUSION Urban activities are inherently noisy. The importance of acoustics even in an urban environment cannot be far-fetched and to enjoy the accrued advantages of living in an urban environment, good acoustics cannot be left out of the picture. It is therefore the duty of architects and planners involved in the design of urban centres to the acoustic comfort of the urban dwellers a priority. Noise interferes with what people are trying to do, can cause damage to health and it has negative psychological and physiological effects, therefore, the planning and design of any urban environment should be done in line with the set acoustic guidelines of the environment in order to achieve maximum acoustic comfort of the urban dwellers. In conclusion, a good acoustic design of an urban environment will be achieved by proper zoning of the urban environment which is the basis for a successful acoustic planning. 10 Acoustic guidelines for urban designs 2014 7.0 RECOMMENDATIONS As a result of the knowledge gathered from the course on acoustics and noise control, the sources of noise in an urban environment, its impacts and control which is achieved by the acoustic guidelines of the urban environment, the following are recommended. The set acoustic guidelines adopted in the urban centres should be adhered to by the planners and architects in their design and also by the residents. Appropriate zoning of the urban environment should be carried out by planners. The acoustic guidelines should be made available to the residents by the government and should not be for those who have the opportunity to know them. Enforcing agencies should be set up in order to enforce the acoustic laws, for example, the acoustic guidelines for construction sites. For urban environments that have been designed or happen to be existing without following acoustic guidelines, noise control measures should be used, for instance, the construction of noise barriers along major transport routes. Buffer zones or intermediate activities should be created between noisy and quiet areas. 11 Acoustic guidelines for urban designs 2014 8.0 REFERENCES Encarta Dictionaries 2009 Encyclopaedia Britannica EPA Victoria publications (2008). “Noise Control Guidelines” http://en.wikipedia.org/wiki/Urban_environment http://en.wikipedia.org/wiki/Guideline Government of South Australia (2014). “Developers’ Handbook & Urban Design Guidelines” Government of South Australia (2013). “Urban Design protocol” Ogunsote, O.O: Environmental control III (Acoustics and Noise Control) Lecture notes, FUT, Akure Passchier-Vermeer W, Passchier WF (2000). “Noise exposure and public health” www.urbandesign.org www.sdngnet.com 12