| Good afternoon. |
| I'm Paula Bundell |
| and I am giving you the lectures on Environmental Noise this term. |
| Today we are going to look into the effects of noise on a planned housing estate |
| in a particularly difficult part of the new Manchester Park area. |
| This site is not as bad as some I have researched in the past. |
| The Blacktown airport is closed from 6 pm to 7 am |
| and this is a great advantage to the site. |
| The only noise after dark is from the highway |
| and the traffic is somewhat reduced between 7.30 pm and 5.30 am. |
| So, the people most affected by the noise will be, I expect, housewives. |
| By the time most of the students and workers have arrived back home in the evening during the week, |
| the noise will have abated to a fairly large extent. |
| The weekends are still a problem of course, |
| but the traffic is certainly reduced on Saturdays to a large extent |
| and even more so on Sundays. |
| Of course, modifications to houses will be necessary at a site like this |
| and they come at a significant cost to the developer and home buyer. |
| The modifications I am about to outline |
| will add about $25,000 to the price of a newly-built house. |
| That will still mean a cheaper house than in a less noisy and more desirable area. |
| A bit of background would not go astray. |
| I understand that you are all familiar with the proposed development site at Manchester Park. |
| It's a particularly difficult one in terms of noise |
| with the highway along the eastern perimeter |
| and the Blacktown airport not 3 kilometres away to the north. |
| Of course, those nearest the highway will be the worst hit, |
| with heavy traffic noise as well as the noise from the light planes overhead. |
| As you all know, the normal noise threshold for private housing is 55 decibels. |
| At this site the levels have been recorded as high as 67 decibels. |
| The construction of the houses has to be somewhat modified from houses in most areas. |
| In the houses on the highway and in the noisiest areas of this site |
| there will be a need for specialised double glazing |
| and special acoustic seals will have to be fitted to the doors. |
| All exterior doors in this especially noisy pocket |
| will have to be solid core wood doors with hinges. |
| Every house built on this site, |
| not just those adjacent to the highway or nearest to the airport, |
| will require high density insulation materials in the roof. |
| Not only will all the roofs need insulating, |
| the exterior walls will be required to be double brick. |
| All ceilings will require double thickness plaster board to be used in the construction. |
| In the noisiest areas, mechanical ventilation will have to be installed in the exterior walls. |
| In those areas with sealed windows |
| it will be necessary to fit fans with absorbers to cut out the noise in those particular houses. |
| Air conditioning units could also be fitted in the ceilings of such houses |
| but this is substantially more expensive than fans, |
| and may not be needed on this site. |
| Coming back now to the double glazing I mentioned before. |
| Specialised double glazing requires a larger air gap |
| between the inner and outer glass than normal double glazing. |
| The gap must be at least 7 centimetres. |
| The thickness of the glass is also a factor, |
| 8 millimetres on the outside and 6 on the inside pane. |
| It's essential that the glass be thicker on the outside than on the inside |
| and that the gap between the panes of glass be a minimum of 7 centimetres. |
| Obviously, the noise factor will have to be taken into consideration with the layout of the houses. |
| Living areas will have to be designed at the back of the houses away from the highway. |
| Bedrooms and living rooms will have to be built towards the back, |
| and for those houses closest to the highway |
| two layers of plasterboard will be needed for the interior bedroom walls. |
| Those rooms constructed at the front of the houses |
| should be garages, laundries, kitchens, bathrooms and dining rooms. |
| I have come to the conclusion that this development should go ahead, |
| but with various acoustic modifications according to the position of the block |
| in relation to the highway and intersection. |