Solar Reflection Analysis

Royal Randwick Racecourse Hotel Australian Turf Club Ltd 21 May 2012

Solar Reflection Analysis

Royal Randwick Racecourse Hotel Solar Reflection Analysis

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Solar Reflection Analysis

Prepared for

Australian Turf Club Ltd

Prepared by AECOM Australia Pty Ltd Level 21, 420 George Street, Sydney NSW 2000, PO Box Q410, QVB Post Office NSW 1230, Australia T +61 2 8934 0000 F +61 2 8934 0001 www.aecom.com ABN 20 093 846 925

21 May 2012

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© AECOM Australia Pty Ltd (AECOM). All rights reserved.

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Quality Information Document Solar Reflection Analysis

Ref

Date 21 May 2012

Prepared by Tim Shotbolt

Reviewed by Leo Trimboli

Revision History

Revision Revision Date Details

Authorised

Name/Position Signature

For DA 21-May-2012 For information Dennis Grech Technical Director



Table of Contents Executive Summary i 1.0 Introduction 1 2.0 Solar charts 2 3.0 Reflection and Specular Surfaces 4 4.0 Methodology for Reflected Sunlight Assessment 4

4.1 Site Analysis 4 4.2 Glare Criterion 5 4.3 Calculation of the Virtual Sun 5 4.4 Luminance Calculations 5

5.0 Project Details 7 5.1 3D Concept Images 7

6.0 Results 9 6.1 Solar Chart Results 9

6.1.1 Glazed façade G1 aspect 131 degrees (high level hotel structure) 9 6.1.2 Glazed façade G2 aspect 71 degrees (high level hotel structure) 10 6.1.3 Glazed façade G3 aspect 11 degrees (high level hotel structure) 11 6.1.4 Glazed façade G4 aspect 311 degrees (high level hotel structure) 12 6.1.5 Glazed façade G5 aspect 250 degrees (high level hotel structure) 13 6.1.6 Glazed façade G6 aspect 326 degrees (low level admin/functions structure) 14 6.1.7 Glazed façade G7 aspect 305 degrees (low level admin/functions structure) 15

6.2 Luminance Calculations 16 7.0 Discussion of Results 18

7.1 Motorists 18 7.1.1 Driving South-East on Alison Rd (Motorist points MP1 and MP2) 18 7.1.2 Driving from Darley Rd (Motorist point MP3) heading towards Alison Rd

intersection and preparing to turn either left into Alison Rd or across the intersection right into Alison Rd. 18

7.1.3 Driving on King St preparing to enter Alison Rd (Motorist point MP4) 18 7.1.4 Driving North-West on Alison Rd (Observer Point MP5) 19 7.1.5 Small Radius corners 20

8.0 Recommendations 20 9.0 Conclusions 21 10.0 References 21 Appendix A - Calculations (Tables 3 to 11) 22 List of Figures:

Figure 1 Stereographic projection of the sun’s path onto a horizontal plane

Figure 2 A typical sun chart showing six months, December through to June

Figure 3 a) Reflectance of various glass surfaces with change in angle of incident light (Hassall, 1991)

b) The higher the angle of incident light the more glass acts like a mirror; also relative to observer’s angle of view.

Figure 4 Schematic of the site, indicating motorist points MP1 through to MP5 and angles of view to higher level hotel structure facades G1 through to G5.

Figure 5 Calculation of the position of the virtual sun relative to a driver’s line-of-sight

Figure 6 3D image representations of proposed Royal Randwick Racecourse Hotel project

Figure 7 Artist rendition of proposed Royal Randwick Racecourse Hotel showing glazed high level hotel structure with inter-leaved fritted graphic incorporated.

Figure 8 General shape relationships of proposed Royal Randwick Racecourse Hotel relative to Alison Road and also showing the footprint of the low level structure over which shown in dashed lines is the high level hotel structure and numbered glazed facades.



Figure 9 High level hotel structure glazed facade G1 facing SE towards Alison Road. No experience of solar reflection as the plotted image of the façade does not intersect the reflected solar sun path

Figure 10 High level hotel structure glazed facade G2 facing NE towards Alison Road. Showing that motorist position MP5 will experience solar reflection late March through to mid-September between 0830 and 1000 hrs. Plotted image of G2 from MP4 does not intersect the reflected sun path and therefore there will be no reflection towards MP4 from G2

Figure 11 High level hotel structure glazed facade G3 facing N towards Alison Road and Darley Road. Motorist positions 1 through to 4 (and the positions in between) will experience some solar reflection during different periods of the year and different times of the day

Figure 12 High level hotel structure glazed facade G4 facing NW towards Alison Road. Motorist position 2 will experience solar reflection after 1630 hrs (no allowance for daylight savings) mid-January to late February and early October to late November. At motorist position 1 there is no solar reflection from G4, however, there will be in between MP1 and MP2 as a motorist travels SE along Alison Road from 1600 hrs through to 1730 hours. varying in the year from mid-January through to mid-November, with that period of exposure depending on the position on the road between MP1 and MP2.

Figure 13 High level hotel structure glazed facade G5 facing SW towards Alison Road. No experience of solar reflection as the plotted image of the façade does not intersect the reflected solar sun path.

Figure 14 Low level admin/functions structure glazed facade G6 facing NW towards Alison Road and Darley Road. G6 is a short pane of glass assumed to be flat (not curved) between two vertical louvres. Motorist position MP3 (and the positions in between MP2 and MP3) will experience some solar reflection during different periods of the year and different times of the day.

Figure 15 Low level admin/functions structure glazed facade G7 facing NW towards Alison Road and Darley Road. G7 is a short pane of glass assumed to be flat (not curved) between two vertical louvres. Motorist position MP2 (and the positions in between MP1 and MP3 including MP2) will experience some solar reflection during different periods of the year late afternoons

Figure 16 Solar reflection from lower Admin/Functions Centre façade showing reflection path and cut-off from proposed louvres

Figure 17 Glare Protractor (Hassall (ref 1) Showing Typical Angles for Sun-visor Cut-off and Average Window Cut-off

List of Tables:

Table 1 Visible reflectance of glass types at 0° incidence

Table 2 Summary of the luminance calculations for observer points MP1 to MP5 and Glazed facades G2, G3, G4, G6, & G7

Table 3 High level hotel structure glazed façade G2 reflection towards motorist position MP5




Table 7 High level hotel structure glazed façade G3 reflection towards motorist position MP4 from west end of

façade

Table 8 High level hotel structure glazed façade G3 reflection towards motorist position MP4 from east end of facade


Table 10 Low level admin/function structure glazed façade G6 reflection towards motorist position MP3




i

Executive Summary AECOM have been engaged in respect to the Director General’s Environmental Assessment Requirements for the development of the new Royal Randwick Racecourse Hotel located on the northern side of the Royal Randwick Racecourse property. This addresses DGR 3 and DGR 6 as follows:

• DGR 3. Built Form and Urban Design

The EIS shall address the following: • the height, bulk and scale of the proposed development within the context of the locality; • visual impacts on views and vistas to and from key buildings, structures, spaces and across

the site from the public domain; • design quality, with specific consideration of the overall site layout, axis, connectivity, open

spaces and edges, primary elements, gateways, facade, rooftop, mechanical plant, massing, setbacks, building articulation, materials, choice of colours; and

• landscape and open space concepts that assist in reducing visual impacts, including planting layout and species.

• DGR 6. Environmental and Residential Amenity

The EIS shall address: • The degree of intensification and impacts on surrounding residential uses including (but not

limited to) solar access, acoustic impacts, visual privacy, security and safety; • servicing requirements (including but not limited to, waste management, loading zones,

mechanical plant); and • The siting of the development in relation to existing significant landscaping on site.• Appendix

B Plans and Documents to accompany the Application

In particular it is to address rogue solar reflections that are likely to occur off the facade of the proposed development and their effect on surrounding observers.

The Royal Randwick Racecourse Hotel site is analysed for solar glare reflected from vertical facades towards selected observer points. The observer points have been selected to represent potentially critical circumstances; motorists travelling in specific directions.

A number of motorist positions have been selected as representative of likely contentious locations whereby motorists might be potentially affected by reflected solar glare from the various facades of the proposed Hotel project. Five observer points, MP1 to MP5 (Figure 4), are selected for the analysis in order to provide an overall assessment of the potential reflected solar glare from the site.

Reflected glare reaching motorists travelling on Alison Road is important with respect to safety, due to the expected high traffic density and vehicle speed. The intersection of Alison and Darley Roads is important due to both traffic and pedestrian interaction. The results presented in Figures 9 through to Figure 15 and Table 2 indicates that there is solar reflection from different facades to different motorist positions during various periods of the year and times of the day. There will also be effects as motorists travelling from one point to another (eg MP1 travelling towards Randwick, that is, towards MP2). The calculations included in Appendix A and summarised in Table 2 indicate that in most instances the reflected glare is below the disability glare threshold stated in reference 1.

However, one high level hotel glazed façade facing NW towards Alison Road (G4) potentially exceeds the threshold of disability glare. There are a number of options to reduce that impact as noted in section 8.0; the issue can be resolved during design development and prior to commencement of construction works.



1

1.0 Introduction AECOM have been engaged in respect to the Director General’s Environmental Assessment Requirements for the development of the new Royal Randwick Racecourse Hotel located on the northern side of the Royal Randwick Racecourse property. This addresses DGR 3 and DGR 6 as follows:

• DGR 3. Built Form and Urban Design

The EIS shall address the following: • the height, bulk and scale of the proposed development within the context of the locality; • visual impacts on views and vistas to and from key buildings, structures, spaces and across

the site from the public domain; • design quality, with specific consideration of the overall site layout, axis, connectivity, open

spaces and edges, primary elements, gateways, facade, rooftop, mechanical plant, massing, setbacks, building articulation, materials, choice of colours; and

• landscape and open space concepts that assist in reducing visual impacts, including planting layout and species.

• DGR 6. Environmental and Residential Amenity

The EIS shall address: • the degree of intensification and impacts on surrounding residential uses including (but not

limited to) solar access, acoustic impacts, visual privacy, security and safety; • servicing requirements (including but not limited to, waste management, loading zones,

mechanical plant); and • The siting of the development in relation to existing significant landscaping on site.•

Appendix B Plans and Documents to accompany the Application

In particular it is to address rogue solar reflections that are likely to occur off the facade of the proposed development and their effect on surrounding observers.

The analysis is based on the following information:

Site plans and elevations

A-1000 dated Feb 2012 Level B1 Plan

A-1001 dated Feb 2012 Ground Level Plan

A-1002 dated Feb 2012 Level 1 Plan




A-4000 dated Feb 2012 Schematic Detail Section

A-4001 dated Feb 2012 Schematic Detail Section

AA40 Rev 0 ATC Hotel 3D View 1, Tonkin zulaikha greer, dated 23/08/11






AA48 Rev 0 ATC Hotel 3D Diagrams 3, Tonkin zulaikha greer, dated 23/08/11

Glass reflectance data taken from VIRACON catalogue decorative silk-screened & spandrel glass specs & tech (at 0° - perpendicular to glass facade); 50% fritted, white fritting, 35% reflection; 50% fritted, grey fritted 22% reflection (2008).



2

2.0 Solar charts The location of the sun at any time of the year can be projected onto a horizontal plane using stereographic projection. The result is a solar sun path chart (refer Figure 1).



3

Figure 1: Stereographic projection of the sun’s path onto a horizontal plane

Inspection of Figure 2 indicates that the sun paths are shown from December 22 to June 21. The second half of the year has identical sun paths returning to December 22. Therefore the following curves on a solar chart represent identical sun paths:

- December 22

- 16 January (27 November)

- 26 February (17 October)

- 21 March (23 September)

- 14 April (31 August)

- 26 May (19 July)

- June 21

The time lines change curvature during the different halves of the year forming a lazy 8 pattern when the full year is shown on the one graph. Reflection sun charts show the mirror image of the sun’s path about the vertical plane of the surface that is being investigated.

Figure 2: A typical sun chart showing six months, December through to June



4

3.0 Reflection and Specular Surfaces Specular surfaces are reflective, irrespective of the opacity of the material. As the angle of the incident light exceeds 60°, relative to the surface normal, the surface tends to exhibit mirror-like qualities. Figure 3a indicates that the amount of light reflected by glass increases with incidence angle, creating a mirror effect as shown in Figure 3b. Glass reflectance is generally specified normal to the surface and some quite low reflectance glass is available upon this basis.

Figure 3: a) Reflectance of various glass surfaces with change in angle of incident light (Hassall, 1991) b) The higher the angle of incident light the more glass acts like a mirror; also relative to observer’s angle of view.

4.0 Methodology for Reflected Sunlight Assessment The Royal Randwick Racecourse Hotel site is analysed for solar glare reflected from vertical facades towards selected observer points. The observer points have been selected to represent motorists travelling in specific directions.

4.1 Site Analysis A number of motorist positions have been selected as representative of likely contentious locations whereby motorists might be potentially affected by reflected solar glare from the various facades of the proposed Hotel project. Five observer points, MP1 to MP5, are nominated for the analysis in order to provide an overall assessment of reflected solar glare from the site. The observer points are selected primarily from the perspective of motorists travelling along Alison Road approaching the proposed project but also for motorists heading SSW on Darley Road turning either left into Alison or right into Alison across the intersection. Also a location is selected for motorists turning south from King Street to join Alison Road heading SSE.



5

Figure 4: Schematic of the site, indicating motorist points MP1 through to MP5 and angles of view to higher level hotel structure facades G1 through to G5.

4.2 Glare Criterion The threshold for unacceptable glare is based on Hassall’s [1] recommendation of a maximum luminance value at the observer point of 500 cd.m-2.

4.3 Calculation of the Virtual Sun A solar chart is a two dimensional representation of the path of the sun throughout the year as indicated in Section 2.0. The orientation of the vertical glass façade is plotted on the sun chart and the sun paths are mirrored about this axis. The reflecting surface of each façade is plotted on a solar chart using the azimuth and altitude angle relative to the observation point. Reflections back to the observation point occur when the path of the virtual sun intersects the plotted façade representation. The particular day and time during which the reflection occurs can be read directly from the intersection on the solar chart. The result does not incorporate daylight savings time.

The position of the virtual sun is calculated according to Figure 5. The algorithms are incorporated into excel spread sheets for rapid calculation. The spread sheets are a direct interpretation of the manual calculations set out in Hassall (1). The calculations are based on specific motorist lines-of-sight and use the sun path information and the relative angles of the façade reflection representation to determine the likely luminance of the sun’s reflected image.

4.4 Luminance Calculations The veiling luminance calculations are completed for the specific task of driving, for which the observer’s viewing direction can be predicted. The direction of view, or bearing as referred to in the calculations, is taken to be along the road in the direction of travel. Veiling luminance is when the amount of light being scattered within the eye of the observer obscures the view as if a veil had been drawn over that person’s eyes.

F2

F4 F6

MP1

MP2 MP3

MP4

MP5

Mature trees to remain although to be trimmed



6

Figure 5: Calculation of the position of the virtual sun relative to a driver’s line-of-sight

The glare limit of 500 cd.m-2 prescribed in [1] relates to disability glare, that is when the amount of glare (or veiling luminance) affects the ability to see the road. The calculations incorporate both the position of the virtual sun relative to a motorist and the motorist’s line of sight along the road. As the visual axis of a motorist moves away from the position of the virtual sun, the magnitude of the calculated luminance decreases. The veiling luminance is calculated using the Holladay Formula [1].

The visible reflectance of the glass types selected for the Royal Randwick Racecourse Hotel proposed development is itemised in Table 1. The quoted Viracon data refers to the visible reflectance at 0° incidence of light, that is at normal to the façade plane; the actual glass reflectance will increase with the angle of incident light as discussed in Section 3.0 and is estimated using Figure 3a.

Table 1: Visible reflectance of glass types at 0° incidence

Glass type Visible reflectance perpendicular to surface Facade

High level hotel structure (average)

25% assumed average (35% to 22% based on mixture of frit tone) G1, G2, G3 G4 G5,

Low level admin and function/restaurant etc 11% G6, G7



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5.0 Project Details

5.1 3D Concept Images The solar reflection analysis is based on the information noted above and the 3D images indicating the proposed completed development.

a) View from Alison Road looking west

b) View from NW of site looking east

Figure 6 3D image representations of proposed Royal Randwick Racecourse Hotel project



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Figure 7 Artist rendition of proposed Royal Randwick Racecourse Hotel showing glazed high level hotel structure

with inter-leaved fritted graphic incorporated.

Figure 8 General shape relationships of proposed Royal Randwick Racecourse Hotel relative to Alison Road and also

showing the footprint of the low level structure over which shown in dashed lines is the high level hotel structure and numbered glazed facades.

G4 G3 G2

G5 G1

G7 G6



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6.0 Results Solar glare analysis comprises two components:

1. Solar charts, which indicate whether or not there is potential solar reflections towards each observer point;

2. Luminance calculations, which determine if the luminance of the solar reflection exceeds 500 cd.m-2.

6.1 Solar Chart Results The solar chart results of Figure 9 to Figure 13 correspond to the observer points MP1 to MP5 and the high level hotel structure glazed facades G1 to G5, which were nominated in Section 4.1. Solar chart results shown on Figures 14 and 15 correspond to low level glazed façade panes G6 and G7. Vertical louvres shown surrounding most of the low level admin/functions structure combined with shading from the overhead high level hotel structure will prevent the possibility of solar reflection in most instances from the low level admin/functions structure toward most motorist positions.

6.1.1 Glazed façade G1 aspect 131 degrees (high level hotel structure)

Figure 9 High level hotel structure glazed facade G1 facing SE towards Alison Road. No experience of

solar reflection as the plotted image of the façade does not intersect the reflected solar sun path

Reflected sun path



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Figure 10 High level hotel structure glazed facade G2 facing NE towards Alison Road. Showing that motorist position MP5 will experience solar reflection late March through to mid-September between 0830 and 1000 hrs. Plotted image of G2 from MP4 does not intersect the reflected sun path and therefore there will be no reflection towards MP4 from G2.

Reflected sun path Real sun path



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Figure 11 High level hotel structure glazed facade G3 facing N towards Alison Road and Darley Road. Motorist positions

1 through to 4 (and the positions in between) will experience some solar reflection during different periods of the year and different times of the day.

Real sun path

Reflected sun path



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Figure 12 High level hotel structure glazed facade G4 facing NW towards Alison Road. Motorist position 2 will

experience solar reflection after 1630 hrs (no allowance for daylight savings) mid-January to late February and early October to late November. At motorist position 1 there is no solar reflection from G4, however, there will be in between MP1 and MP2 as a motorist travels SE along Alison Road from 1600 hrs through to 1730 hours. varying in the year from mid-January through to mid-November, with that period of exposure depending on the position on the road between MP1 and MP2.

Real sun path Reflected sun path



13


Figure 13 High level hotel structure glazed facade G5 facing SW towards Alison Road. No experience of solar

reflection as the plotted image of the façade does not intersect the reflected solar sun path.

Real sun path Reflected sun path



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6.1.6 Glazed façade G6 aspect 326 degrees (low level admin/functions structure)

Figure 14 Low level admin/functions structure glazed facade G6 facing NW towards Alison Road and Darley Road. G6 is a short pane of glass assumed to be flat (not curved) between two vertical louvres. Motorist position MP3 (and the positions in between MP2 and MP3) will experience some solar reflection during different periods of the year and different times of the day.

Real sun path

Reflected sun path



15

6.1.7 Glazed façade G7 aspect 305 degrees (low level admin/functions structure)

Figure 15 Low level admin/functions structure glazed facade G7 facing NW towards Alison Road and Darley

Road. G7 is a short pane of glass assumed to be flat (not curved) between two vertical louvres. Motorist position MP2 (and the positions in between MP1 and MP3 including MP2) will experience some solar reflection during different periods of the year late afternoons.



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6.2 Luminance Calculations

Table 2 summarises the presence and magnitude of solar reflections expected at each of the observer locations. The data corresponds to the solar charts plotted in Figure 9 to Figure 15; details of the luminance calculations are provided in Appendix A.

Table 2: Summary of the luminance calculations for observer points MP1 to MP5 and Glazed facades G2, G3, G4, G6, & G7

Observer Location Facade

Driver viewing direction (BRG)

Presence of solar reflections

Months Time (without daylight savings)

Angle above

horizon

Luminance Value (cd.m-2)

Acceptable (ie < 500)

Comments

MP1

Alison Road heading towards Randwick

High level hotel structure G3 116 April thru to mid-May and late July thru to end of August

0630 to 0715 hrs 5 395 yes

MP2

Alison Road heading towards Randwick but possibly preparing to turn left into Darley Road

Low level admin/functions structure G7

175

September and March 1715 thru to 1745 hrs 6 16 yes

High level hotel structure G3 Mid April thru to last August

0730 thru to 0930 hrs 13 201 yes

High level hotel structure G4 Start of October to late November and mid-January to late-February

1645 thru to 1845 hrs 17 670 No Assumes no obscuration by trees (refer 7.1.1)

MP3

Darley Road heading SW towards Alison Road intersection

High level hotel structure glazed façade G3

219

End May thru to mid-July

0850 hrs 18 24 yes

Low level admin/functions structure G6

Late March thru to mid-April and late September thru to early October

1730 thru to 1800 hrs 8 165 yes

MP4

King Street preparing to enter Alison Road

West end high level hotel structure glazed façade G3

175

Start of May thru to end July

1200 thru to 1500 hrs 25 23 yes

East end high level hotel structure glazed façade G3

Start of May thru to end July

1000 thru to 1200 hrs 39 153 yes

MP5

Alison Road heading High level hotel structure G2 304

Late march thru to mid-September

0830 to 1000 hrs 23 174 Yes



17

towards the City



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7.0 Discussion of Results

7.1 Motorists Reflected glare reaching motorists travelling on Alison Road is important with respect to safety, due to the expected high traffic density and vehicle speed. The intersection of Alison and Darley Roads is important due to both traffic and pedestrian interaction. The results presented in Figures 9 through to Figure 15 and Table 2 indicates that there is solar reflection from different facades to different motorist positions. There will also be effects as motorists travel from one point to another (eg MP1 travelling towards Randwick towards MP2). The calculations included in Appendix A and summarised in Table 2 indicate that in most instances the reflected glare is below the disability glare threshold stated in reference 1. One high level hotel glazed façade facing NW towards Alison Road (G4) exceeds the threshold of disability glare, an issue that will be resolved during design development and prior to commencement of construction works.

7.1.1 Driving South-East on Alison Rd (Motorist points MP1 and MP2)

MP1 is a point where there is a potential view of the proposed project high level hotel structure (depending on screening from adjacent foliage) as shown in Figure 11 and there will be reflected glare towards that point from the long north facing façade in the morning 0630 thru to 0715 hours April through to mid-May and late July through to end of August although the calculated value as summarised in Table 2 is below the disability threshold (ref 1).

In the mornings as the motorist travels towards MP2 there will continue to be reflection from the high level hotel structure north façade beginning to decline as the reflection only comes from the east end of the façade, mid-April through to late August, 0730 through to 0930 hours. The calculated value is below the disability threshold (ref 1).

During the afternoon 1645 through to 1845 hours, beginning of October through to mid-November and mid-January through to mid-February, the north-west façade (Figure 12) reflects the sun towards the motorist and to the point that at MP2 the disability glare threshold is exceeded and no longer acceptable (Table 2) without some further change to arrangements (refer Recommendations 7.2). The sun will strike the façade and reflect toward motorists although the reflected light will be obscured to varying degrees by the trees identified in Figure 11. It is possible that part of the façade could be screened from view by the use of vehicle sun-visors (refer Figure 17) as the top of the façade will be approximately 8 degrees above the horizontal and sun-visors can cut-off down to 5 degrees.

Figure 15 shows that there will be some reflection from the lower admin/functions facade G7 to MP2, however, Table 2 shows the value of veiling glare to be quite low and well below the disability threshold (ref 1). Figure 16 shows that the proposed vertical louvres do not provide much shielding towards MP2, however, the incident sun is at a low angle (table 2) and most likely to be shielded by existing trees (the opposite side of Alison Road) which means there is unlikely to be any solar reflection.

7.1.2 Driving from Darley Rd (Motorist point MP3) heading towards Alison Rd intersection and preparing to turn either left into Alison Rd or across the intersection right into Alison Rd.

In the mornings at approximately 0850 hours end of May through to mid-July there will be some reflection from the east edge of the high level hotel structure façade towards MP3 (Figure 11), however, Table 2 shows the value of veiling glare to be quite low and well below the disability threshold (ref 1).

Likewise, Figure 14 shows that there will be some reflection from the lower admin/functions facades G6, however, Table 2 shows the value of veiling glare to be quite low and well below the disability threshold (ref 1). Figure 16 indicates that the proposed vertical louvres will have limited effect for this particular circumstance, however, the incident sun is at a low angle (table 2) and most likely to be shielded by existing trees which means there is unlikely to be any solar reflection.

7.1.3 Driving on King St preparing to enter Alison Rd (Motorist point MP4)

MP4 is a point where there is a potential view of the proposed project high level hotel structure as shown in Figure 11 and there will be reflected glare towards that point from the long north facing façade in the morning 1000 hours through to 1500 hours May through to end of July although the calculated value as summarised in Table 2 is below the disability threshold (ref 1).



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7.1.4 Driving North-West on Alison Rd (Observer Point MP5)

Motorist location MP5 is clear of potential screening by foliage. There is a potential view of the proposed project high level hotel structure as shown in Figure 10 and there will be reflected glare towards that point from the north-east facing façade in the morning 0830 hours through to 1000 hours mid-April through to late August although the calculated value as summarised in Table 2 is below the disability threshold (ref 1).

Figure 16: Solar reflection from lower Admin/Functions Centre façade showing reflection path and cut-off from proposed louvres.



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7.1.5 Small Radius corners

For the high level hotel structure small radius corners (NW and NE) shown on the proposed floor plans are likely to be a series of short flat planes arranged around small radii. Each small plane may potentially reflect the sun to a particular location at a particular time of year and period of the day. If, however, those corners are constructed from curved glass the angular size of the effect will be even less, however, the zone through which there may be an effect will be wider. The very small angular size of that plane(s) as viewed from any one location combined with travel means that at worst there may be a momentary flash of solar reflection insignificant in comparison with the aspects being analysed earlier in the report and not considered further.

8.0 Recommendations The NW facing façade of the high level hotel structure (G4) has the potential to provide solar reflection to motorists on Alison Road but that can be reduced by any one or a combination of the following options:

1. Reduce the visible light reflectance of the proposed façade at normal to the surface to approximately 17 percent or less reducing the solar reflection below the threshold for disability glare (ref 1);

2. In the vertical plane tilt the top of the façade towards Alison Road by 20 degrees. This could be staggered in a series of steps preventing solar reflection to Alison Road;

Figure 17: Glare Protractor (Hassall (ref 1) Showing Typical Angles for Sun-visor Cut-off and Average Window Cut-off.



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9.0 Conclusions There will be solar reflection from the proposed Royal Randwick Racecourse Hotel facades towards motorists. Reflected glare reaching motorists travelling on Alison Road is important with respect to safety, due to the expected high traffic density and vehicle speed. The intersection of Alison and Darley Roads is important due to both traffic and pedestrian interaction.

The results presented in Figures 9 through to Figure 15 and Table 2 indicates that solar reflection from different facades to different motorist positions occurs during different periods of the year and times of the day. The effects are not just at the selected analysis locations (MP’s) but at points in between as well as motorists travel from one point to another (eg MP1 travelling towards Randwick, that is towards MP2).

The calculations included in Appendix A and summarised in Table 2 indicate that in most instances the reflected glare is below the disability glare threshold stated in reference 1, however, one high level hotel glazed façade facing NW towards Alison Road (G4) potentially produces reflected solar glare that exceeds the threshold of disability glare although there may be some obscuration of the reflected light by existing trees (Figure 11). There are a number of potential options to reduce that impact as noted in section 8.0; the issue can be resolved during design development and prior to commencement of construction works.

10.0 References 1. Reflectivity, Dealing with Rogue Solar Reflections, D N H Hassall, 1991



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Appendix A - Calculations (Tables 3 to 11) Veiling luminance calculations caused by solar reflection from glazed facades towards Motorist Positions (MP1 through to MP5).


Location: MP5 Alison Rd heading towards the City

Month: Mid April thru to Late August

Time: 0900 hrs

Façade Aspect (ASP): 71

Direction of View (BRG) : 304

Sun position:

AZI 47

ALT 23

Solar Power (w/m2): 695

Luminous Efficacy (lm/w): 125

Solar Illumination(lux): 86875

Solar Position relative to Façade:

HAS (deg) -24

VSA (deg) 24.9

I (deg) 32.8

Virtual Sun position:

VALT(deg) 23

VAZI(deg) -85

VAZI(deg) absolute 275

Glare position relative to observer:

Alpha (deg) -29

Beta (deg) 23

Theta (deg) 36.4

Reflectivity of glass:

At normal (%) 25

At angle of incidence

Read corresponding value from report Figure 3(a) 32.8 33

Fraction of façade spectrally reflective:

1.0 Illumination at observer's eye due to glare

source in plane normal to line of sight (lux): 23080 Equivalent veiling luminance - Holladay

formula (cd/m2): 174

Provisional limit to veiling luminance of 500 cd/m2 is situation acceptable? Yes



23


Location: MP1 Alison Rd heading towards

Randwick


Time: 0645 hrs



Sun position:

AZI 73

ALT 5





HAS (deg) 62

VSA (deg) 10.6

I (deg) 62.1


VALT(deg) 5

VAZI(deg) -231



Alpha (deg) 13

Beta (deg) 5

Theta (deg) 13.9


At normal (%) 25






formula (cd/m2): 395 Provisional limit to veiling luminance of

500 cd/m2: is situation acceptable? Yes



24


Location: MP2 Alison Rd heading towards

Randwick


Time: 0730 thru to 0930 hrs



Sun position:

AZI 60

ALT 13





HAS (deg) 49

VSA (deg) 19.4

I (deg) 50.3


VALT(deg) 13

VAZI(deg) -218



Alpha (deg) 26

Beta (deg) 13

Theta (deg) 28.9


At normal (%) 25










25


Location: MP3 Darley Rd heading towards Alison

Rd intersection

Month: end May thru to mid July

Time: 0850 hrs



Sun position:

AZI 43

ALT 18





HAS (deg) 32

VSA (deg) 21.0

I (deg) 36.2


VALT(deg) 18

VAZI(deg) -201



Alpha (deg) -60

Beta (deg) 18

Theta (deg) 61.6


At normal (%) 25










26

Table 7 High level hotel structure glazed façade G3 reflection towards motorist position MP4 from west end of facade

Location: MP4 King St entering Alison Rd

Month: Start of May thru to end July




Sun position:

AZI 322

ALT 25





HAS (deg) 311

VSA (deg) 35.4

I (deg) 53.5


VALT(deg) 25

VAZI(deg) -480

VAZI(deg) absolute -120


Alpha (deg) -295

Beta (deg) 25

Theta (deg) 67.4


At normal (%) 25










27

Table 8 High level hotel structure glazed façade G3 reflection towards motorist position MP4 from east end of facade

Location: MP4 King St entering Alison Rd

Month: Start of May thru to end July




Sun position:

AZI 22

ALT 39





HAS (deg) 11

VSA (deg) 39.5

I (deg) 40.3


VALT(deg) 39

VAZI(deg) -180



Alpha (deg) 5

Beta (deg) 39

Theta (deg) 39.3


At normal (%) 25










28


Location: MP2 Alison Rd heading towards Randwick

Month: Start of October thru to mid November and mid January thru to mid February

Time: 1645 thru to 1845 hrs Façade Aspect (ASP): 311

Direction of View (BRG) : 175 Sun position:

AZI 265 ALT 17

Solar Power (w/m2): 605 Luminous Efficacy (lm/w): 117

Solar Illumination(lux): 70785 Solar Position relative to Façade:

HAS (deg) -46

VSA (deg) 23.8

I (deg) 48.4 Virtual Sun position:

VALT(deg) 17

VAZI(deg) 177

VAZI(deg) absolute 177 Glare position relative to observer:

Alpha (deg) 2

Beta (deg) 17

Theta (deg) 17.1 Reflectivity of glass:

At normal (%) 25

At angle of incidence Read corresponding value from report Figure 3(a) 48.4 29

Fraction of façade spectrally reflective: 1.0 Illumination at observer's eye due to glare source in

plane normal to line of sight (lux): 19618 Equivalent veiling luminance - Holladay formula

(cd/m2): 670 Provisional limit to veiling luminance of 500

cd/m2: is situation acceptable? No



29


Location: MP3 Darley Rd heading towards Alison Rd intersection

Month: late March thru to mid April and late

September thru to early October

Time: 1730 to 1800 hrs



Sun position:

AZI 270

ALT 8





HAS (deg) -56

VSA (deg) 14.1

I (deg) 56.4


VALT(deg) 8

VAZI(deg) 202



Alpha (deg) -17

Beta (deg) 8

Theta (deg) 18.7


At normal (%) 11



Fraction of façade spectrally reflective: 1.0

Illumination at observer's eye due to glare source in plane normal to line of sight (lux): 5796

Equivalent veiling luminance - Holladay formula (cd/m2): 165

Provisional limit to veiling luminance of 500 cd/m2: is situation acceptable? Yes



30


Location: MP2 Alison Rd heading towards Randwick

Month: September and March Time: 1715 thru to 1745 hrs

Façade Aspect (ASP): 305 Direction of View (BRG): 116

Sun position: AZI 276

ALT 6 Solar Power (w/m2): 300

Luminous Efficacy (lm/w): 90 Solar Illumination(lux): 27000

Solar Position relative to Façade: HAS (deg) -29 VSA (deg) 6.9 I (deg) 29.6

Virtual Sun position: VALT(deg) 6 VAZI(deg) 154 VAZI(deg) absolute 154

Glare position relative to observer: Alpha (deg) 38 Beta (deg) 6 Theta (deg) 38.4

Reflectivity of glass: At normal (%) 11 At angle of incidence

Read corresponding value from report Figure 3(a) 29.6 11 Fraction of façade spectrally reflective: 1.0

Illumination at observer's eye due to glare source in plane normal to line of sight (lux):

2327

Equivalent veiling luminance - Holladay formula (cd/m2):

16

Provisional limit to veiling luminance of 500 cd/m2: is situation acceptable?

Yes

Date post:	27-Dec-2021
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