7 REPORT ON EXISTING NOISE CLIMATE

Transcription

1 7 REPORT ON EXISTING NOISE CLIMATE PRESENTED BY

2 St Modwen Lodge Farm, Rugby Proposed new village settlement Existing noise climate 19/09/17 Revision 4

3 Tel: +44 (0) AUDIT SHEET Hoare Lea Acoustics 6 th Floor West 54 Hagley Road Edgbaston Birmingham B16 8PE Revision Description Date Issued by Reviewed by 0-DFC Survey Report 30/06/2017 AMcC 1 Design team comments 21/08/2017 AMcC DM 2 Minor amendments 14/09/2017 AMcC DM 3 Design team comments 19/09/2017 AMcC DM 4 Updated Masterplan AMcC DM This report has been prepared for St Modwen only and expressly for the purposes set out in an appointment and we owe no duty of care to any third parties in respect of its content. Therefore, unless expressly agreed by us in signed writing, we hereby exclude all liability to third parties, including liability for negligence, save only for liabilities that cannot be so excluded by operation of applicable law. The consequences of climate change and the effects of future changes in climatic conditions cannot be accurately predicted. This report has been based solely on the specific design assumptions and criteria stated herein. REP AM-R4 Audit page

4 Contents 1. INTRODUCTION SITE DEVELOPMENT PROPOSALS BASIS OF ASSESSMENT National Planning Policy Framework BS8233: MEASUREMENTS RESULTS DISCUSSION Existing noise climate BS8233 Assessment RECOMMENDATIONS CONCLUSIONS APPENDIX 1: PROPOSED SITE MASTERPLAN APPENDIX 2: MEASURED SOUND PRESSURE LEVELS APPENDIX 3: LIST OF MEASUREMENT EQUIPMENT APPENDIX 4: GLOSSARY OF TERMS REP AM-R4 Contents page

5 1. Introduction Assessment has been made of the existing ambient noise climate at a site off the A45 Daventry Road to the south of Rugby on behalf of St Modwen. The emerging Rugby Borough Council Local Plan proposes that the site be developed as a new village of up to 1,500 dwellings. This report details the results of all site measurements and reviews this data with respect to applicable guidance and standards for new residential development as well as local planning requirements. REP AM-R4 Page 1

6 2. Site The site is an area of open land located approximately 2 miles south of Rugby Town centre and lies immediately to the west of the A45 Daventry Road and to the south of the M45 motorway. The A45 forms the eastern site boundary and provides a principal traffic route between Rugby town centre and M45 to the north and Daventry to the south. The road is reasonably busy during the daytime period with fast, free flowing, traffic but flow rates reduce significantly during the evening and into the night time. Main Street forms the north west boundary and provides local access from the A45 to the village of Grandborough to the south west of the site. Traffic flows on this road are very light with only occasional vehicle movements. All other boundaries adjoin open land but with some existing residential properties to the west off Castle Lane and Main Street. An aerial view of the site and surroundings is shown below. REP AM-R4 Page 2

7 3. Development proposals It is proposed that the site be developed as a New Settlement Allocation within the emerging Rugby Borough Local Plan. The development is to comprise a new village of up to 1,500 dwellings, employment land and a local centre including retail use, a primary school and a G.P surgery. The development is currently intended to be carried out in three phases and will mostly comprise residential properties. The development will also include provision for sports and leisure facilities and some, limited, employment use. Employment use is expected to be located adjacent to the A45 and towards the centre of the site. The current site masterplan is shown at Appendix 1. Detailed site layouts are not yet available but it is intended that dwellings will not be built immediately adjacent to the A45 but will be set back from the road beyond a landscaping zone and internal access roads in order to reduce traffic noise impact from the A45. It is noted that the development site primarily adjoins open land or else the A45 and that there are only a small number of existing residential properties in the vicinity of the site where these properties do occur, they are invariably part of working farms. Given these conditions, the site is unlikely to have any significant impact upon existing residential properties either during construction or upon completion. Any future noise impacts from commercial uses on the site will have to be adequately controlled to minimise impact for the new residential development. REP AM-R4 Page 3

8 4. Basis of assessment 4.1 National Planning Policy Framework The National Planning Policy Framework (NPPF) 2012 sets out the Government planning policies for England and how these are expected to be applied. Section 11, Conserving and enhancing the natural environment, para 123 of NPPF states: Planning policies and decisions should aim to: Avoid noise from giving rise to significant adverse impacts on health and quality of life as a result of new development Mitigate and reduce to a minimum other adverse impacts on health and quality of life arising from noise from new development, including through the use of conditions Recognise that development will often create some noise and existing businesses wanting to develop in continuance of their business should not have unreasonable restrictions put upon them because of changes in nearby land uses since they were established Identify and protect areas of tranquillity which have remained relatively undisturbed by noise and are prized for their recreational and amenity value for this reason Reference is made to the DEFRA Noise Policy Statement for England 2010 (NPSfE). This latter document is intended to apply to all forms of noise other than that which occurs in the workplace and includes environmental noise and neighbourhood noise in all forms. NPSfE advises that the impact of noise should be assessed on the basis of adverse and significant adverse effect but does not provide any specific guidance on assessment methods or limit sound levels. Moreover, the document advises that it is not possible to have a single objective noise-based measure that is applicable to all sources of noise in all situations. It further advises that the sound level at which an adverse effect occurs is likely to be different for different noise sources, for different receptors and at different times. In the absence of specific guidance for assessment of environmental noise within NPPF and NPSfE it is considered appropriate to base assessment on current British Standards and appropriate local or national guidance. It is noted that NPSfE also advises that the general principle that increases in ambient noise should be minimised, needs to be considered in context for each site and, in this regard, states: Of course, taken in isolation and to a literal extreme, noise minimisation would mean no noise at all. In reality, although it has not always been stated, the aim has tended to be to minimise noise as far as is reasonably practical... the application of the NPSfE should enable noise to be considered alongside other relevant issues and not to be considered in isolation. In the past, the wider benefits of a particular policy, development or other activity may not have been given adequate weight when assessing the noise implications. REP AM-R4 Page 4

9 4.2 BS8233: 2014 BS8233:2014 Guidance on sound insulation and noise reduction for buildings is the current British Standard providing guidance and recommendations for the acoustic design of buildings. The Standard advises appropriate criteria and limits for different building types including dwellings. Criteria for dwellings, generally, are in accordance with the guidance provided by the World Health Organisation. BS8233 provides guidance regarding acceptable internal and external noise level criteria for dwellings but does not form any statutory requirement to achieve the guidance values provided therein. The BS8233 internal design criteria for dwellings are as follows: Activity Location 07:00 to 23:00 23:00 to 07:00 Resting Living rooms 35 db LAeq,16hour - Dining Dining Room / Area 40 db LAeq,16hour - Sleeping (daytime resting) Bedroom 35 db LAeq,16hour 30 db LAeq,8hour BS 8233 Section Note 7 advises that where developments are necessary or desirable, the internal design criteria may be relaxed by up to 5dB and reasonable living conditions still achieved. BS 8233 Section G1 advises that, where windows are open for ventilation, then sound reduction is limited to 15dB. It is noted that this value applies to the window only and that, within a room, further sound reduction would be likely to occur from room finishes. For gardens and terraces, the Standard states that it is desirable that the steady noise level does not exceed LAeq,T 50dB whilst a level of LAeq,T 55dB would be acceptable in noisier environments. REP AM-R4 Page 5

10 5. Measurements Hoare Lea Acoustics has carried out a measurement survey to establish the prevailing noise climate at the development site. The survey comprised automated logged noise level measurements at two locations over a seven day period between Friday 14 th and Thursday 20 th October Measurements were made in 1-minute sample periods to determine the LAeq, LAmax and LA90 indices. The measurement locations are indicated on the site aerial view at Section 2 above and described below. Location ref: Description 1 Continuous logging position located towards the north eastern site boundary near to the A45 Daventry Road at a distance of 15 metres from the nearest kerb 2 Continuous logging position towards the western site boundary Weather conditions over the survey period were reasonably dry with occasional wind and temperatures ranged between 2 and 16 Celsius. obtained is representative of the overall noise climate at the site. It is considered that the measurement data All measurements were made with a calibrated precision grade sound level meter in accordance with BS EN and BS 7445:1993. All equipment was calibration-checked before and after the survey no significant drift was observed. A list of the equipment used can be found in Appendix 3. REP AM-R4 Page 6

11 6. Results The results of all diurnal site measurements are tabulated in Appendix 2. Levels are shown as hourly values derived from the measured 1 minute samples. Position 1 A summary of the measured levels over the survey period is given in the table below: Period Mean L Aeq L Amax Mean LA10 Mean L A90 Thursday (13:00 23:00) Thursday night Friday Friday night Saturday Saturday night Sunday Sunday night Monday Monday night Tuesday Tuesday night Wednesday (07:00 13:00) The mean weekday daytime ambient noise level was LAeq,16hr 64.6dB. The mean weekday night time ambient noise level was LAeq, 8hr 61.7dB. The survey data indicates that typical maximum night time levels were in the range LAmax 75-83dB but with the majority of night time events below LAmax 78dB. Position 2 A summary of the measured levels over the survey period is given in the table below: REP AM-R4 Page 7

12 Period Mean L Aeq L Amax Mean LA10 Mean L A90 Thursday (13:00 23:00) Thursday night Friday Friday night Saturday Saturday night Sunday Sunday night Monday Monday night Tuesday Tuesday night Wednesday (07:00 14:00) The mean weekday daytime ambient noise level was LAeq,16hr 47.0dB. The mean weekday night time ambient noise level was LAeq, 8hr 40.6dB. The survey data indicates that typical maximum night time levels were in the range LAmax 45-62dB but with the majority of night time events below LAmax 60dB. REP AM-R4 Page 8

13 7. Discussion 7.1 Existing noise climate The survey indicates that the general noise climate across the site is attributable to road traffic noise and with no other noticeable noise sources. Highest sound levels are generated by the A45 adjacent to the site but additional lower level noise is generated by the M45 approximately 1km to the north. The traffic noise evident at the site was mostly attributable to tyre roar which has a characteristic mid-frequency peak at 500Hz-2kHz. 7.2 BS8233 Assessment Internal noise levels Based upon the site measurement data, it may be extrapolated that the building fabric to dwellings would need to provide a minimum composite sound reduction of the order of 30dB for daytime resting and 32dB for night time sleeping at measurement position L1 and 12dB and 11dB respectively for measurement position L2. The exact requirements for facades nearest to the A45 will vary where the distance to the road differs from the measurement position and where there are any forms of acoustic treatment to the boundary adjacent to the A45. With the proposed development, there will be additional sound reduction across the site attributable to screening by intervening buildings and it is anticipated that sound reduction requirements for all facades beyond the building line overlooking the A45 would be below 20dB for the majority of dwellings on the eastern side of the site. For dwellings on the western side of the site and further from the A45, sound reduction requirements are expected to be below 10dB. In practice, the structural components of the building envelope can be expected to provide a sound reduction in excess of 45dB and will not provide a significant pathway for noise break-in. Greatest sound break-in can be expected to occur via windows. Data given in BRE IP 12/89 and BS 8233 indicates that standard thermal double glazing provides a typical sound reduction of the order of 33dB(A) for road traffic noise This order of reduction would enable the BS 8233 internal criteria to be achieved for all dwellings throughout the development. BS 8233 notes that regular individual noise events during the night can cause sleep disturbance. Glazing achieving a typical sound reduction of the order of 33dB would reduce internal maximum levels during night time to less than LAmax 45dB for all dwellings provided they are not within 15m of the A45. REP AM-R4 Page 9

14 7.2.2 Open Windows The sound reduction requirements discussed above apply to closed windows and BS8233 Section G1 advises that sound reduction across a partially open window will be limited to 15dB. For sound levels within a room, there will be further reduction due to room furnishings. From available test data, the typical overall sound reduction from outside to inside is 19dB with the window open 100mm. This order of reduction would enable BS 8233 criteria to be achieved in all habitable rooms throughout the development with the exception of those rooms which directly overlook the A45. For these latter rooms, it is noted from the survey data for position 1 that typical evening sound levels are in the range LAeq 60-62dB which would suggest a shortfall of 6-8dB for the BS 8233 good criteria and a shortfall of just 1-3dB for the BS 8233 reasonable criteria. It is probable that the shortfalls noted could be resolved by introduction of modest screening measures near to the road boundary or else by positioning the first line of dwellings slightly further back from the road. For those habitable rooms on elevations immediately overlooking the A45 where there is likely to be a shortfall to BS 8233 criteria with open windows, it will be necessary to provide alternative means of ventilation. Background ventilation in accordance with Building Regulations requirements can be achieved with proprietary window or wall mounted trickle vents Gardens and outdoor areas Existing noise levels across the majority of the site currently achieve the BS 8233 criteria for gardens and outdoor areas. For plots near to the A45, the BS 8233 criteria may be exceeded if gardens are not screened from the road. Where gardens are screened from the road by intervening dwellings, they will benefit from increased distance attenuation and from screening by the dwelling. It is anticipated that the combined reduction from these factors will be at least 10dB which would enable gardens in these locations to achieve the BS 8233 limit criterion of LAeq 55dB. Noise levels in the gardens to all plots beyond the first line of development will benefit from screening provided by intervening dwellings. Given this screening and the increased distance to the road, it is considered that all remaining gardens throughout the development will achieve the BS 8233 preferred criterion of LAeq 50dB. REP AM-R4 Page 10

15 8. Recommendations It is recommended that the building line of dwellings nearest to the A45 be set back at least 15m from the edge of the road in order to reduce traffic noise impact. Windows to all habitable rooms overlooking the A45 should have a minimum manufacturer's rating of Rw 33. All remaining habitable windows throughout the development should have a minimum manufacturer s rating of Rw 30. All habitable rooms all habitable rooms overlooking the A45 should also be provided with proprietary wall or window mounted trickle vents to achieve background ventilation in accordance with the Building Regulations requirements. All such vents should, when open, have a minimum manufacturer s rating of Dnew 35. Consideration should be given to provision of landscaping treatments along the A45 boundary to further reduce the impact of traffic noise upon the residential areas of the site. The majority of traffic noise from the A45 is attributable to tyre roar which is generated at the road surface and, consequently, relatively low level screening along this boundary can have a significant benefit for the site. REP AM-R4 Page 11

16 9. Conclusions Measurements and observations made at this site indicate that the existing noise climate, primarily, is determined by traffic flows on the A45 Daventry Road but with additional background traffic noise from the M45 motorway to the north. Traffic noise impact upon the development site will only be of significance for dwellings located adjacent to the A45 and sound levels for the majority of the site are relatively low. The BS 8233 criteria within dwellings can be achieved by use of appropriate acoustic rated windows and vents for habitable rooms near to the A45. The survey data indicates that BS 8233 requirements for gardens are currently achieved across the majority of the site. Depending upon the final site layout, it may be necessary to provide limited control measures for any gardens adjacent to the A45. Given the findings noted above, the site is considered to be suitable for residential development in accordance with the guidance given in BS The site mostly adjoins open land and, consequently, there is little potential for noise impact upon existing residential properties. Those few residential properties that are near to the site all appear to be within working farms where there will be existing noise sources. Noise impacts from any new commercial uses within the new development will need to be controlled to minimise impact upon new residential properties. Such control measures will also be adequate for any existing residential properties. It is noted that the proposed employment area is located adjacent to the A45 where existing ambient and background sound levels are highest and that there are no existing noise sensitive properties in the vicinity of the proposed employment area. Given these circumstances, it is very unlikely that the proposed employment area would have any significant upon existing noise sensitive premises. Given the proximity of the M45 and A45 to the site which are existing busy roads, it is not expected that noise from traffic flows associated with the proposed development would result in any significant change in noise impact for residential districts to the north or south of the site. REP AM-R4 Page 12

17 Appendix 1 - Proposed site masterplan REP AM-R4 Page 13

18 Appendix 2 - Measured sound pressure levels Position 1 15m from A45 Day From To L Aeq L Amax L A10 L A90 Thursday 15:00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Friday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: REP AM-R4 Page 14

19 14:00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Saturday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: REP AM-R4 Page 15

20 16:00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Sunday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: REP AM-R4 Page 16

21 18:00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Monday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: REP AM-R4 Page 17

22 20:00 20: :00 21: :00 22: :00 23: Tuesday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: REP AM-R4 Page 18

23 22:00 22: :00 23: Wednesday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: Position 2 Western Boundary Day From To L Aeq L Amax L A10 L A90 Thursday 15:00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: REP AM-R4 Page 19

24 22:00 22: :00 23: Friday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: REP AM-R4 Page 20

25 Saturday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Sunday 00:00 00: :00 01: REP AM-R4 Page 21

26 02:00 02: :00 03: :00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Monday 00:00 00: :00 01: :00 02: :00 03: REP AM-R4 Page 22

27 04:00 04: :00 05: :00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Tuesday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: REP AM-R4 Page 23

28 06:00 06: :00 07: :00 08: :00 09: :00 10: :00 11: :00 12: :00 13: :00 14: :00 15: :00 16: :00 17: :00 18: :00 19: :00 20: :00 21: :00 22: :00 23: Wednesday 00:00 00: :00 01: :00 02: :00 03: :00 04: :00 05: :00 06: :00 07: REP AM-R4 Page 24

29 08:00 08: :00 09: :00 10: :00 11: :00 12: :00 13: Note that maximum noise levels presented above are the highest level measured in each one-hour period. REP AM-R4 Page 25

30 Appendix 3 - List of measurement equipment Measurements Rion Type NL-52 Sound Level Meter S/N Rion Type NA-31 Sound Level Meter S/N The above equipment fulfils IEC Class 1 and is traceable to calibration under BS7580: Part 1:1997. The equipment was calibration-checked before and after measurement no adverse deviation was observed. REP AM-R4 Page 26

31 Appendix 4 - Glossary of Terms Decibel (db) The decibel is the unit used to quantify sound pressure levels. The human ear has an approximately logarithmic response to acoustic pressure over a very large dynamic range (typically 20 micro-pascals to 100 Pascals). Therefore, a logarithmic scale is used to describe sound pressure levels and also sound intensity and power levels. The logarithm is taken to base 10, hence, an increase of 10 db in sound pressure level is equivalent to an increase by a factor of 10 in the sound pressure level (measured in Pascals). Subjectively, this increase would correspond to a doubling of the perceived loudness of sound. A-Weighting The A weighting is a correction term applied to the frequency range in order to approximate to the sensitivity of the human ear to noise. It is generally used to obtain an overall noise level from octave or third octave band frequencies. An A weighted sound level is written as db(a). L Aeq,T The A-weighted equivalent continuous sound level the level of a notionally steady sound having the same energy as the fluctuating sound over a specified measurement period (T). LAeq,T is used to describe many types of noise and can be measured directly with an integrating sound level meter. It is the preferred descriptor for environmental noise in accordance with BS 7445:1993. L A90,T The A-weighted noise level exceeded for 90% of the specified measurement period (T). This is generally taken to indicate the prevailing background noise level. L A10,T The A-weighted sound level exceeded for 10% of the specified measurement period (T). This parameter is indicative of the average maximum sound level L Amax The highest short duration A-weighted sound level recorded during a noise event. REP AM-R4 Page 27