TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 NOISE; A MENACE IN HOUSING ESTATES

2.1 SOURCES OF NOISE IN HOUSING ESTATES 2.1.1 External sources of noises 2.1.2 Internal sources of noise 3.0 NOISE CONTROL 3.1 EXTERNAL NOISE CONTROL 3.1.1 SCREENING 3.1.2 PLANNING 3.1.3 BUILDING DESIGN 3.1.4 INSULATION 3.2 INTERNAL NOISE CONTROL 3.2.1 REDUCTION AT SOURCE 3.2.2 USE OF ABSORBENT SCREEN AND SURFACES 3.2.3 INSULATION 3.2.4 BUILDING DESIGN AND CONSTRUCTION 4.0 CASE STUDY (IJAPO HOUSING ESTATE) 4.1 BRIEF DESCRIPTION 4.2 EXISTING SITUATION 4.2.1 Sources of noise in Ijapo Housing Estate 5.0 RECOMMENDATIONS AND CONCLUSION 5.1 Recommendations 5.2 Conclusions References 1.0 INTRODUCTION

Noise is any form of unwanted sound which is virtual and subjective in nature. (Harris, 1975) defines noise as a form of sound which is unwanted, annoying, interferes with speech and enough to damage hearing, while Salvato (1982) defines noise as ‘unwanted sound’. The hazardous effect of loud or unwanted sound (noise) has been a growing concern in our society especially in our urban areas where noise has been one of the major forms of pollution. The problems of noise in residential buildings have over the years been a menace that affects quality of life. This paper is centered on how noise can be controlled within housing estate, though it is borne in the mind that noise cannot be totally eradicated within residential environment. For housing conditions to satisfy its primary goal as a total environment where human being lives, effective measures should be put into consideration to control the noise generated or put noise under a bearable level. A housing estate is a planned environment with most people residing in it in order to be free from environmental pollutions; noise in particular. It has been observed noise is still been generated from housing estate which are meant to be extremely quiet and for the purpose of this paper, Ijapo housing estate in Akure metropolis has been chosen as a case study. 2.0 NOISE; A MENACE IN HOUSING ESTATES It has been shown that excessive noise can have a lasting adverse effect upon on health, lower efficiency at work and is considered by many people as diminishing to their quality of life. It has been noted that the perceptivity of different individual to noise differs. It is a fact that it is possible for people to get used to certain degree noises or to find a minimum background noise level as being quiet pleasant. The objective of noise control is the reduction of unwanted sound (noise) to tolerable levels. The source and what constitutes the unwanted noise should first be determined. The second step is to refer to standards that give acceptable levels for different situation in building. Also the psychological and physiological effect of sound on human beings should be known to guide against the danger of such harmful effects when designing.

2.1 SOURCES OF NOISE IN HOUSING ESTATES The sources of noise within housing estates are generally classified into two; the external source and the internal source of noise. 2.1.1 External sources of noises This is noise generated from sources outside the building. It cannot be insulated totally but it can be refined to a bearable level. These are noise from various forms of transport, industrial, commercial noise, institutional and noise from adjoining residential areas. The main ways by which external air borne noise enters a dwelling is through windows, doors, gaps in walls and through the roof In general, even the most inadequate solid brick or concrete walls have external, good resistance to air bone noises and can therefore be ignored, except when the constitute party walls between adjoining dwellings.

2.1.2 Internal sources of noise This can either be noise associated with occupants’ activities and operations of the building services. The major sources of internal noise in housing estate are:  Noise from home appliances this could be noise from generator, television, radio, kitchen equipments e.g. blender, grinder and other home appliances that generates noise within the building  People:-Some sounds and vibrations produced by occupants includes door slam, footfall which is a nemesis in multi residential buildings  Activities of the occupants. 3.0 NOISE CONTROL

3.1 EXTERNAL NOISE CONTROL External noise can be controlled by employing the following method:  Screening  Planning  Building Design  Insulation

3.1.1 SCREENING Screening is most commonly used in controlling traffic noise, as in the case of a highway passing near a housing estate. The screen can be made from walls, hedges or other barriers. Landscaping plays an important role in the choice of screens. The most effective position for a screen is nearest the source. 3.1.2 PLANNING Screening effects of barriers Site planning plays an important role in noise control. The first role is the placement of the building far away from noise sources. This noise sensitive to buildings are placed farthest and they receive additional protection from less sensitive buildings, for example, garages, stores and churches are placed nearer the no source. In a case where there are strongly directional sources of sound rise, been should be the location of the building (Lyneh & Hak, 1990). Trees and landscaping are additional tools that may be employed.

3.1.3 BUILDING DESIGN From the inception of a building design, an architect should put into consideration the noise that will be generated from the activities of the residents of the building. Noise from within a building originates from people, bathroom, kitchen and appliances. Noise can be control by zoning spaces with respect to the amount noise generated in the space; Noisy, quiet, and semi quiet zone. This spatial segregation can effectively reduce noise transmission. Noisy spaces such as kitchen, laundry, stair, and lobby should be grouped together. Quiet spaces such as bedroom, study should be grouped together. The functional layout of buildings should place noisy zones such as bathroom and kitchen nearer to noise source, hence quite zones such as bedroom will thus be protected. The position and orientation should prevent noise penetration and special elements such as long walls and screen may be used as additional protection. 3.1.4 INSULATION Another important aspect of room acoustics is insulation from unwanted sound. This is obtained by carefully sealing even the smallest openings that can leak sound, by using massive walls, and by building several unconnected walls separated by dead spaces. The use of sound insulating materials in external walls openings can reduce external noise. Increasing the thickness of walls and reducing the size of openings in them improves their sound insulation. Improving the quality of road surface within the housing estate can also help to reduced traffic noise. 3.2 INTERNAL NOISE CONTROL Internal noise control can be achieved by the implementation of the following.  Reduction at source  Use of absorbent screen and surface  Insulation  Building design and construction

3.2.1 REDUCTION AT SOURCE This is usually applicable when noise is due to vibrating machinery and house electric appliances. Flexible mountings are used to prevent transmission of vibration to building structures. However, in the case of airborne sound an insulating enclosure around the source is used.

3.2.2 USE OF ABSORBENT SCREEN AND SURFACES The finishes or material use for the surface of some in dwellings can act as noise screen in the building. For instance soft wood paneling will absorb noise or sound more than concrete walls. Also the fabric materials like window blind furniture and so on will also act as good sound absorber in the dwelling. There are four types of absorbent materials  Porous absorbents (Best for high frequencies)  Membrane absorbents (Best for low frequencies)  Resonant absorbers (Resonator)  Perforated panel absorbent 3.2.3 INSULATION The reduction of transmission of sound could be effectively achieved by sound insulation. Noisy equipments such as generator may thus be placed in well insulated enclosure. Air borne sound can be reduced by airtight and noise insulating constructions. Structure-borne sound can be reduced by creating sound gap, separating structures (walls).

3.2.4 BUILDING DESIGN AND CONSTRUCTION In the case of multi-storey building the major forms of noise transmission are through structure borne sound an impact sound. This can be solved by the provision of elastics medium between the noise and the solid structure of the building especially from the impact noise. It is essential that: (a) The system is continuous without any sound bridges such as nails or screws causing sound across. (b) The material used as insulation damping material should not have the same frequency as source of the sound being transmitted. If this is reduced rather increased due to resource, it is necessary for the ratio of facing frequency to natural frequency to exceed 1.4 for insulation to occur, and for all practical purposes we should aim at an insulation system where the natural frequency is less than about one third of the lowest frequency to be expected in the sound against which it is desired to insulate. (c) Residence of the damping material is necessary which mean that elastic limit should not be exceeded even during long periods of usage. 4.0 CASE STUDY (IJAPO HOUSING ESTATE)

4.1 BRIEF DESCRIPTION The Ijapo housing estate is a residential development located in the north-east part of Akure; the capital city of Ondo state. The housing estate accommodates civil servants who register for housing units with the Housing Corporation. Divided into different zones for high, middle and low income earners, the estate still seems like the most popular within the Akure metropolis. With two major entrances, the estate roughly accommodates about 600buildings; both developed and those under construction. A major road connects the two major entrances, intertwining itself between the cluster of buildings and attached to it, are other minor roads link that link the various sectors.

4.2 EXISTING SITUATION While data was being collated as to identify the sources of noise within the housing estate, some individuals were interview and they identified the sources as:  Improper land use on the part of individuals  Lack of proper education  Economic factors

During our survey, we gathered that majority of the occupants of the housing estate are quite observant of the noise menace around their homes.

4.2.1 Sources of noise in Ijapo Housing Estate The external sources of noise are classified as commercial, industrial, residential and institutional while road traffic noise posing as the most commonly noticed. Details of the existing noise menace are explained below with pictures of the noise-building sources. The Redeemed ChristianResidential Buildings Church: with Its shops and retail loudspeakers are sourcesoutlets: of Commercial noise especially activities contribute to during Sunday servicesthe noise level The live band crew at Solton hotel disturbs the Road traffic; the principal source of noise estate tranquility at night with high megawatt within the housing estate speakers

Noise from a 250KVA Lister engine generator The mini market within the estate serves as a at the NETRYDER service provider office that major source of noise due to the many runs 24hours is another commercial activities that is accommodates

Ijapo High School; falls within the institutional Another view of the school showing some noise cadre. Noise is generated here during the blocks of classrooms and one administrative working hours block NOISE CONTROL MEASURES IN IJAPO HOUSING ESTATE

Site planning accounts for noise reduction Trees are often used as buffer zones to muffle measure taken against traffic noise filtering the effect of noise from the road and into the hotel bedrooms in Solton Hotel adjoining buildings

Adequate setbacks are observed while planning the Royal Birds Motel. A buffer zone also exists behind the fence 5.0 RECOMMENDATIONS AND CONCLUSION

5.1 RECOMMENDATIONS

The problems of noise in housing estate have over the years been a threat to the quality of life of its residents. However noise cannot be totally taken away from our environment, but it can be reduce to a bearable level for housing condition to satisfy its primary goal as a total environment where human being lives, which consequently should be devoid of unpleasant situation and most especially when noise is involved. The active participations of government, architects and other professionals in the building industry can help to reduce this issue.

5.2 CONCLUSION

Many times, a building design that its architectural acoustics was not put into consideration are usually unpleasant after construction. A space with acoustic problems is unusable, requiring major retrofit to restore functionality. The best way to remedy a project’s acoustic issues is dependent upon the exact circumstances.

However noise can still be controlled from by using indoor and outdoor noise control methods.

REFERENCES

Acoustics.com (2005): Project Remedies-Controlling Noise between Spaces. Adapted from Architectural Acoustics, M. David Egan and Sound Analysis and Noise Control, John E.K. Foreman

Lyneh, K. and Hak, G. (1984): Site Planning. Pub MIP Press Cambridge Massachusetts and London, England, pp. 60 – 62, 412 - 419 Microsoft Encyclopedia Encarta Acoustics, Sound, Ear and Noise. Deluxe (2003)

Ogunsote O. O. (2005): Lecture notes on acoustics.

Olotuah A. O. (2005): Lecture notes on housing seminars.