DAYLIGHT, SUNLIGHT AND OVERSHADOWING The EXO Building at Point Village North Wall Quay & East Wall Road, Dublin 1. For Grant Thornton, on behalf of the Specified Assets of Henry A. Crosbie (In Receivership)
DAYLIGHT, SUNLIGHT AND OVERSHADOWING 1. INTRODUCTION This report comprises an assessment of the likely potential daylight, sunlight, overshadowing impacts associated with the proposed development of a commercial building of The Exo Building and associated public realm works, including a Glass Box restaurant café, at Point Village Square, Dublin 1. It is proposed to develop The Exo Building as a linear building to the east of the former Point Depot, now the 3Arena, and along the East Wall Road. The building will range from 8 to 17 storeys in height, with the taller element extending into Point Village Square. In addition, a range of public realm works are proposed, including a Glass Box restaurant/café within Point Village Square which will assist in providing a sense of enclosure along the eastern side of Point Village Square. The proposed Exo Building and Glass Box restaurant café are indicated in red on Figure 1 below. Figure 1: Location of proposed development
2. SUNLIGHT, DAYLIGHT AND OVERSHADOWING Sunlight, Daylight and Overshadowing assessment is normally carried out with particular regard to potential impacts on the living spaces and private open spaces of residential properties, but assessments may also extend to include amenity spaces such as public spaces, parks, playing fields and playgrounds between nondomestic buildings and in streetscapes. In the case of the proposed development, there are no existing residential properties within the immediate vicinity. The guidance documents, referenced below, indicate that site specific characteristics be taken into account when carry out assessments. As such, the locations of the spaces assessed in this report are provided below in Section 4: Assessment. Methodology The assessment of the impacts of the proposed development was prepared using the methodology set out in BRE 209, Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice, Second Edition 2011, by P. J. Littlefair. This is the non-statutory guide referred to in the Dublin City Council Development Plan 2011 2017, and sets out guidelines that are most commonly used in Ireland and the UK to assess the impacts of development on daylight and sunlight. It provides advisory numerical targets that represent good practice; however, the location specific characteristics of each site must also be taken into account. This report uses these guidelines to assess the likely impacts on sunlight, daylight and overshadowing of the proposed development on nearby properties and public spaces. It is noted that the guidance is intended to be used in conjunction with the interior daylighting recommendations in British Standards BS 8206-2 Code of Practice for Daylighting, and in the CIBSE publication Lighting guide: daylighting and window design. These publications provide specific advice and design consideration at new rooms and windows which are part of the development, and may themselves be susceptible to adverse lighting impacts arising from other parts of the same development. The advice in these publications is not applicable to existing receptors that are outside of the proposed development. Sunlight The BRE Report recommends that loss of sunlight should be checked for main living rooms of dwellings, and conservatories, if they have a window facing within 90 of due south. If the development wholly lies due north, then sunlight loss need not be analysed. Sunlight can be quantified in terms of the Annual Probable Sunlight Hours (APSH) for any given location. Annual Probable Sunlight Hours is the total number of hours in the year that the sun is expected to shine on unobstructed ground while allowing for average monthly levels of cloud cover for the specific location. The APSH for any given location depends on its latitude and longitude which determines the number of daylight hours for any particular location, but also on statistical records for that location which indicates the number of daylight hours that are likely to experience sunshine. The number of daylight hours in Dublin ranges from 7hrs 30mins on 21 st December to 17hrs 00mins on 21 st June. Over the whole year, there are a total of 4410 daylight hours. In order to determine sunlight hours, statistical data is available from Met Eireann that identifies the mean daily duration of sunshine for each month of the year averaged over the 30 year period from 1961 to 1990, recorded at Dublin Airport.
Table A: Average monthly sunshine hours recorded at Dublin Airport from 1960 to 1990 Month Daylight Hours Average Sunlight Hours Factor January 245.1 55.8 22.80% February 268.8 70.0 26.00% March 360.6 111.6 30.90% April 412.5 156.0 37.80% May 483.8 189.1 39.10% June 499.1 180.0 36.10% July 502.1 167.4 33.30% August 452.2 158.1 35.00% September 376.8 129.0 34.20% October 323.9 96.1 29.70% November 254.8 72.0 28.30% December 229.1 52.7 23.00% Total 4408.8 1437.8 32.60% Winter 1677.3 465.2 27.70% While the average percentage of daylight hours likely to experience sunshine is 32.60%, this varies substantially from just below 23% in January to just over 39% in May. The BRE Report recommends that the centre of the window, or in the case of a patio door, a point 1.6m above floor level, should receive at least 25% of the APSH, including at least 5% of the APSH from 21 st September to 21 st March. If the available sunlight hours become less than this, and less than 0.8 times their former value, either over the whole year or just in the winter months, then a noticeable loss of sunlight can occur. If the overall annual loss is greater than 4% of APSH, rooms may appear colder and less pleasant. For Dublin, 25% of the APSH, totalling 1,438 hours as seen in Table A, equates to 25% of 1438 hours, or 359.5 hours. During winter, from 21 st September to 21 st March, there should be a minimum of 5% of 1423 hours, or 71 hours of sun. Annual recommended target Winter recommended target 359.5 probable sunlight hours 71.9 probable sunlight hours A Sunpath Diagram is used to calculate the Annual Probable Sunlight Hours for any given reference point. Sunpath Diagrams are generated for different longitudinal locations using solar data for different days of the year at times of day. The Sunpath Diagram comprises a plot of the path of the sun as seen from a particular location on different days of the year and at different times of the day. Generally, sunlight in the lowest six degrees of elevation is discounted to take account of existing built or planted obstructions at or near the horizon. Existing and proposed developments outside the reference point can also be plotted onto the diagram, and the dates and times at which the suns path will be obstructed by these can be determined from the plots. The Sunpath Diagram provides a numeric value for the total number of daylight hours during each month during which the sun would not be blocked by any physical obstructions, but assuming an otherwise unobstructed clear sky throughout all the hours of daylight. This value, together with the statistical factor in Table A, can then produce the probable sunlight hours for each month, and in turn, for the whole year as well as the winter months. Brady Shipman Martin has developed its own specialised software for preparing Sunpath diagrams for specific locations using standard 3D CAD models. This plots the direction and altitude of the sun for every two minutes and every day of the year and checks whether any elements of the 3D model obstruct
the line of sight from the sun to particular reference points. It then calculates the total number of hours of daylight during which sun obstruction will occur. Sunpath Diagrams at test reference points are presented in Section 4 below. The Sunpath Diagrams are projections as seen from the test reference points, and the different elements of existing and proposed development are indicated using different coloured lines so that the relative positions of obstructions can be readily seen. The colour coding is as follows: Blue: Cyan: Green: Existing buildings or structures, within or external to the site, to be retained Canopies and brise soleil on existing buildings The proposed development Sunpath Diagrams show the full 360 panorama from each reference point, and the 180 portion of the panorama that faces into the room and cannot receive sun is shaded in yellow. Within the unshaded part, the intersection of the sunpath curves and the projection of the different elements of existing and proposed development are used to calculate the current and post construction access to sunlight hours. Daylight The BRE Report recommends the calculation of the Vertical Sky Component. The Vertical Sky Component (VSC) is defined as The ratio of that part of illuminance, at a point on a given vertical plane that is received directly from a CIE Standard Overcast Sky, to illuminance on a horizontal plane due to an unobstructed hemisphere of this sky. The maximum possible VSC value for an opening in a vertical wall, and assuming no obstructions, is 40%. BRE 209 indicates that if the VSC can be maintained above 27%, then enough skylight should still reach the window of an existing building. If the resultant VSC is both less than 27% and less than 0.8 times its former value after the construction of the proposed development, occupants of the building will notice a reduction in skylight. In order to calculate the VSC for a particular reference point, a Waldram Diagram is used. A Waldram Diagram is a geometric representation of the portion of the sky vault which might be visible from a particular reference point. Obstructions outside the window are plotted onto the diagram, and the remaining clear area can be calculated as a percentage of the complete unobstructed sky vault. Brady Shipman Martin has developed its own specialised software for preparing Waldram Diagrams using 3D digital models of the existing and proposed environment. This projects the 3D model onto the Waldram Diagram, and the projection is then used to calculate those parts of the sky that will be either obstructed or not in order to calculate the Vertical Sky Component at each test reference point. Waldram Diagrams are presented in this report for test reference points in Section 4 below. Like Sunpath Diagrams, Waldram Diagrams are projections as seen from the test reference points, where different elements from the existing and proposed development are indicated using different coloured lines so that the relative positions of obstructions can be readily seen. The colour coding is as follows: Blue: Cyan: Green: Existing buildings or structures, within or external to the site, to be retained Canopies and brise soleil on existing buildings The proposed development Waldram Diagrams only show the portion of the sky that can be seen from the reference point, and therefore, the whole area of diagram is relevant for calculation purposes. The areas of obstructed and unobstructed parts of the sky are calculated to determine the VSC.
Overshadowing The BRE Report acknowledges the value of sunlight in external spaces in enhancing their overall appearance, ambience and amenity. Relevant spaces noted in the report include private gardens of dwellings, amenity spaces such as parks, playing fields and playgrounds, and also public spaces between non-domestic buildings and in streetscapes. The report recommends that at least half of the area of relevant spaces should receive at least two hours of sunlight on 21 st March. In order to determine, and to quantify, the effect of overshadowing of the proposed development on the adjoining public spaces and properties, Sunlight Exposure Plans and Shadow Plans are prepared using 3D digital models of existing buildings and structures in and around the Point Village and of the proposed development. Sunlight Exposure Plans identify the areas of the ground plane that will be capable of receiving different durations of sunlight on any given day of the year. Sunlight exposure plans are prepared from the 21 st March, and identify areas that will receive up to 1 hour of sunlight, areas that will receive 1 to 2 hours, and areas that will receive more than 2 hours of sunlight. Shadow Plans provide a more conventional graphic representation, however, each one only represents a specific period of time on the 21 st March. Shadow plans are prepared for 09:00am, 12:00 noon, and 03:00pm on the 21 st March.
3. RECEIVING ENVIRONMENT Context and Location The development site is located along the eastern side of the Point Village Square, occupying the space between the 3Arena and the East Wall Road, and extending from North Wall Quay into Point Village Square. Dublin Port lies immediately east of East Wall Road, and in the vicinity of the development site, comprises marshalling and storage yards with a small number of associated administration and security buildings. The 3Arena is located on the western side of the development site, and extends from the North Wall Quay to Point Village Square. Its eastern façade is substantially solid, and any windows and doors serve internal back of house circulation areas and fire escape routes. The Point Village District Centre is located to the north of the site and forms the northern edge of Point Village Square. The southern part of the District Centre facing Point Village Square comprises the Gibson Hotel, commercial office space, and ground floor retail units. Point Village Square is a public space located between the 3Arena and the Point Village District Centre. At present, it extends from the existing Point LUAS station eastwards to East Wall Road, and the space continues around the 3Arena on the eastern side to North Wall Quay. The closest residential development is at Castleforbes Square on the northern side of Mayor Street Upper, over 200m from the development site as indicated in Figure 2 below in yellow Figure 2: Local context of proposed development, including closest residential uses, and indicating the horizontal and vertical elements of The Exo building.
Characteristics of the Proposed Development The proposed development comprises a number of elements, including: The Exo Building: a linear commercial building facing east and west, to be located along the eastern side of the former Point Depot, now the 3Arena, and along the East Wall Road. The building will be raised some 8.0m above ground supported on three separate elliptical cores, allowing the public space to flow freely underneath the building. The building is expressed as two distinct but connected volumes. The southern part, approximately 2/3 of the overall building footprint, is 8 storeys high, and the northern part rises to 17 storeys. The overall length of the proposed Exo Building is similar to that of the 3Arena, however, The Exo building will be positioned slightly further north. This allows the creation of a small public space at the southern end that addresses North Wall Quay and the River Liffey, and also partly extends The Exo Building into Point Village Square at the northern end so as to create a sense of enclosure to the public space, and to be a focal point and city marker that will be visible from along Mayor Street. The Public Realm: reconfiguration of parts of Point Village Square to provide enclosure along the East Wall Road side of its current configuration, and to integrate the public space under the Exo Building with the 3Arena and the main part of Point Village Square, and to provide connectivity between the various elements. A Glass Box restaurant/café, some 10.0m in height, in the main part of Point Village Square will be part of the public realm and, in conjunction with The Exo Building, will create a sense of enclosure in the space. For a full scheme description, see the Planning Report.
4. ASSESSMENT A set out above, there are no residential dwellings in sufficient proximity to the proposed development to warrant detailed assessment for impacts on access to daylight, sunlight or for overshadowing. Given the location of the proposed Exo Building, Glass Box and public realm works relative to existing buildings in the vicinity, and the function, orientation and arrangement are existing buildings, a number of reference points have been identified for which to carry out quantified assessment using the same standards that would be applied to the living spaces of dwellings. The Gibson Hotel, although commercial, incorporates a range of room types and spaces that could be considered either public spaces of private accommodation, albeit of a temporary nature. Within the Gibson Hotel, spaces identified for assessment of Daylight and Sunlight include: A. Ground Floor retail units of the Point Village District Centre facing Point Village Square B. The Third Floor restaurant of the Gibson Hotel C. The Fourth Floor guest rooms of the Gibson Hotel. Reference Points A, B and C are clearly identified on Figures 3 and 4 below. In relation to Overshadowing, the public space of Point Village Square is assessed. For Reference Points A and B, Sunlight and Daylight analysis has been undertaken in two manners. The first set of calculations take into consideration the substantial overhangs of the first floor terrace and the brise soleil above the third floor as relevant. The second calculations omit the presence of the terrace and brise soleil. In the case of Reference Point C at the fourth floor guest room, there is no existing overhang to regulate or obstruct access to light, and a single set of calculations is provided. Assessment of access to daylight sunlight where rooms are set back under terraces and other such features is specifically referenced in BRE 209, Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice, Second Edition 2011, by P. J. Littlefair, It is considered reasonable to measure the access to light at the outer edge of the terrace, even for living spaces of residential properties, as the space of the terrace is for the enjoyment of those using the adjacent internal space. In all cases assessed, the existing trees are omitted as recommended in the guidelines.
Figure 3: Location of test reference points for Daylight, Sunlight and Overshadowing Figure 4: Location of test reference points for Daylight and Sunlight assessment
Point A: Ground Floor retail unit, glass frontage facing Point Village Square. Point A, as indicated in Figures 3 and 4 above, is the eastern-most ground floor retail under the Gibson Hotel facing Point Village Square. The glass front enclosure is set back c. 3.0m from the colonnade that supports the first floor terrace above. As such, the frontage of the retail unit as it exists at present is substantially shielded from direct sunlight. In addition, there is a row of trees c. 5.0m outside the colonnade that creates further shading from direct sunlight. Photo 1: Test Reference Point A is at the glazed front of the retail units. Taking the terrace into account, Table A1 below, and Figures A1 and A2 further below, show the existing Daylight value, VSE Before, is 15.1% and significantly below the recommended target of 27.0%. Post construction, this will reduce further to 9.5%, or 0.629 times the current value. Table A1 also shows the existing Sunlight access is 407.7 hrs annually, or 28.35% of the APSH, and 289.3 hrs or 20.12% of the APSH during the winter months. Post construction, these will reduce to 273.1 hrs annually, or 18.99% of the APSH, and 153.5 hrs or 10.68% of the APSH during the winter months. On this basis, the annual result post construction is slightly below the target of 25.0% of APSH, but the Winter component, before and after construction, is well above the recommended 5% APSH. Table A1: Vertical Sky Component and Annual Probable Sunlight Hours at Reference Point A Reference Point A: Ground Floor retail unit, incorporating the first floor terrace overhang Vertical Sky Component, % VSC Before VSC After Ratio 15.1% 9.5% 0.629 Annual Probable Sunlight Hours Annual APSH = 1437.8 hrs APSH Before APSH After Ratio 407.7 hrs 273.1 hrs 0.670 28.35% 18.99% Winter PSH = 465.2 hrs 289.3 hrs 153.5 hrs 20.12% 10.68% 0.531
By omitting the terrace overhang, the results are significantly different, as shown in Table A2. It shows the existing Daylight value, VSE Before, is 33.7% and well above the recommended target of 27.0%. Post construction, this will reduce to 25.4%, slightly lower than the target 27%, and marginally lower than 0.8 times the current value. Table A2 also shows the existing Sunlight access is 990.7 hrs annually, or 68.91% of the APSH, and 342.7 hrs or 23.84% of the APSH during the winter months. Post construction, these will reduce to 764.7 hrs annually, or 53.19% of the APSH, and 181.0 hrs or 12.59% of the APSH during the winter months. On this basis, the annual result is well above the target of 25.0% of APSH, and the Winter component is also well above the recommended 5% APSH. Table A2: Vertical Sky Component and Annual Probable Sunlight Hours at Reference Point A Reference Point A: : Ground Floor retail unit, omitting the first floor terrace overhang Vertical Sky Component, % VSC Before VSC After Ratio 33.7% 25.4% 0.754 Annual Probable Sunlight Hours Annual APSH = 1437.8 hrs APSH Before APSH After Ratio 990.7 hrs 764.7 hrs 0.772 68.91% 53.19% Winter PSH = 465.2 hrs 342.7 hrs 181.0 hrs 23.84% 12.59% 0.528 The form and layout of the existing retail unit, set back under the terrace overhang, is such that the existing access to daylight by residential standards is poor, and access to sunlight is just above the residential recommendations. By considering the space outside the unit and under the overhang as being part of the amenity of the unit, it is clear that the access to both daylight sunlight by residential standards greatly exceeds the recommendations. The relative impacts of the existing buildings (the 3Arena), the existing terrace overhang, and the proposed development on both Daylight and Sunlight, can be clearly seen in Figures A1 and A2 below. The dark blue outline indicates the existing buildings, and they obstruct a relatively small area of the sky or the sunpaths. The cyan colour indicated the profile of the terrace overhang, and everything above that line in both the daylight and sunlight diagrams is obstructed by the terrace. The green colour outlines the proposed development, and although it illustrates a 17 storey development, it obstructs much less daylight or sunlight than the existing terrace overhang. Retail units typically make extensive use of artificial lighting as a means of presenting attractive window displays and creating internal ambience. The level of obstruction to daylight and to sunlight caused by the existing terrace overhang is substantially greater than any increased obstruction anticipated by virtue of this development. Given the retail use of the space, and the pre-existence of the overhang, it is considered that the impact of the proposed development on daylight and sunlight will be slight, and would be appropriate in an urban context.
Figure A1: Point A: Ground Floor retail unit. Waldram Diagram Figure A2: Point A: Ground Floor retail unit. Sunpath Diagram KEY to Waldram and Sunpath Diagrams above Blue: Existing buildings or structures, within or external to the site, to be retained Cyan: Canopies and brise soleil on existing buildings Green: The proposed development
Point B: Third Floor restaurant unit, on terrace in line with main building wall. Point B, as indicated in Figures 3 and 4 above, is the eastern part of the third floor restaurant terrace overlooking Point Village Square. The restaurant is enclosed by a glass wall that leads onto the seating terrace. The Reference Point in this instance is taken on the terrace itself, at a point that is in line with the main building wall. It is where the seating space joins the walking space along the terrace as shown in Photo 2 below. It should be noted that the restaurant is in fact dual aspect and it also enjoys the light provided by an atrium at the core of the building as shown in Photo 3 below. Photo 2: Test Reference Point B is at the edge of the seating area on the terrace. Photo 3: Interior of restaurant (terrace to the right) with additional atrium lighting on left.
Taking the brise soleil into account, and treating it as solid even though it does permit some reflected light through, Table B1 shows the existing Daylight value, VSE Before, is 9.6% and substantially below the recommended target of 27.0%. Post construction, this will reduce further to 6.5%, or 0.677 times the current value. Table B1 also shows the existing Sunlight access is 277.4 hrs annually, or 19.29% of the APSH, and 235.9 hrs or 16.41% of the APSH during the winter months. Post construction, these will reduce to 202.4 hrs annually, or 14.08% of the APSH, and 157.0 hrs or 10.92% of the APSH during the winter months. On this basis, the annual result, before and after construction, is below the target of 25.0% of APSH, and the post construction value is just under 0.8 times the existing value, but the Winter component, before and after construction, is well above the recommended 5% APSH. Note that the values do not include any additional daylight contribution arising from the atrium space, nor any additional daylight that is reflected as diffuse light through the brise soleil system overhead. Table B1: Vertical Sky Component and Annual Probable Sunlight Hours at Reference Point B Reference Point B: Third Floor restaurant unit, incorporating the brise soleil overhead Vertical Sky Component, % VSC Before VSC After Ratio 9.6% 6.5% 0.677 Annual Probable Sunlight Hours Annual APSH = 1437.8 hrs APSH Before APSH After Ratio 277.4 hrs 202.4 hrs 0.730 19.29% 14.08% Winter PSH = 465.2 hrs 235.9 hrs 157.0 hrs 16.41% 10.92% 0.666 By omitting the brise soleil overhang, the results are significantly different, as shown in Table B2. It shows the existing Daylight value, VSE Before, is 36.3% and well above the recommended target of 27.0%. Post construction, this will reduce to 30.1%, which is still well above the target 27%. Table A2 also shows the existing Sunlight access is 988.0 hrs annually, or 68.72% of the APSH, and 379.5 hrs or 26.39% of the APSH during the winter months. Post construction, these will reduce to 849.4 hrs annually, or 59.08% of the APSH, and 267.7 hrs or 19.24% of the APSH during the winter months. On this basis, the annual and winter month results are both well above the target values of 25.0% of APSH, and 5% APSH during the winter months. Table B2: Vertical Sky Component and Annual Probable Sunlight Hours at Reference Point B Reference Point B: Third Floor restaurant unit, omitting the brise soleil overhead Vertical Sky Component, % VSC Before VSC After Ratio 36.3% 30.1% 0.829 Annual Probable Sunlight Hours Annual APSH = 1437.8 hrs APSH Before APSH After Ratio 988.0 hrs 849.4 hrs 0.860 68.72% 59.08% Winter PSH = 465.2 hrs 379.5 hrs 276.7 hrs 26.39% 19.24% 0.729
The design and layout of the existing restaurant and terrace space, incorporating a substantial brise soleil, clearly indicates that regulation of daylight and sunlight has been an inherent part of the design in the existing building and appropriate to the restaurant use. The terrace space outside the restaurant is clearly part of the amenity of the restaurant, and it is clear that the access to both daylight and sunlight is highly regulated by inherent design, and that application of residential standards for this use is not appropriate. This is particularly true for daylight, and it is notable that the relatively small reduction in sunlight will occur only in the early to mid-morning period of the winter months. The relative impacts of the existing buildings (the 3Arena), the existing terrace overhang, and the proposed development on both Daylight and Sunlight, can be clearly seen in Figures B1 and B2 below. The dark blue outline indicates the existing buildings, and they obstruct a very small area of the sky or the sunpaths. The cyan colour indicated the profile of the brise soleil overhang, and everything above that line in both the daylight and sunlight diagrams is obstructed by the brise soleil. The green colour outlines the proposed development, and while it illustrates a 17 storey development, it obstructs much less daylight or sunlight than the existing brise soleil overhang. Given the restaurant use of the space, and the existence of the brise soleil that is an inherent part of the design of space, it is considered that the impact of the proposed development on daylight and sunlight will be slight, and would be appropriate in an urban context.
Figure B1: Point B: Third Floor restaurant terrace. Waldram Diagram Figure B2: Point B: Third Floor restaurant terrace. Sunpath Diagram KEY to Waldram and Sunpath Diagrams above Blue: Cyan: Green: Existing buildings or structures, within or external to the site, to be retained Canopies and brise soleil on existing buildings The proposed development
Point C: Fourth Floor guest room. Point C, as indicated in Figures 3 and 4 above, is the eastern-most guest room window at the fourth floor overlooking Point Village Square. The Reference Point in this instance is at the window plane. Table C shows the existing Daylight value, VSE Before, is 36.6% and substantially above the recommended target of 27.0%. Post construction, this will reduce to 30.7% but will remain substantially above the 27.0%. Table C also shows the existing Sunlight access is 970.2 hrs annually, or 67.48% of the APSH, and 377.8 hrs or 26.28% of the APSH during the winter months. Post construction, these will reduce to 840.6 hrs annually, or 58.47% of the APSH, and 275.2 hrs or 19.14% of the APSH during the winter months. On this basis, the annual result, before and after construction, is substantially above below the target of 25.0% of APSH, and the winter component in both instances is also substantially above the recommended 5% APSH. Table C: Vertical Sky Component and Annual Probable Sunlight Hours at Reference Point C Reference Point C: Fourth Floor guest accommodation, at window. Vertical Sky Component, % VSC Before VSC After Ratio 36.6% 30.7% 0.839 Annual Probable Sunlight Hours Annual APSH = 1437.8 hrs APSH Before APSH After Ratio 970.2 hrs 840.6 hrs 0.866 67.48% 58.47% Winter PSH = 465.2 hrs 377.8 hrs 275.2 hrs 26.28% 19.14% 0.728 The results above, and as illustrated in Figure C1 and C2 below, clearly demonstrate that access to both daylight and sunlight will greatly exceed standards for residential living spaces. It is considered that the impact of the proposed development on daylight and sunlight will be negligible.
Figure C1: Point C: Fourth Floor guest room. Waldram Diagram Figure B2: Point C: Fourth Floor guest room. Sunpath Diagram KEY to Waldram and Sunpath Diagrams above Blue: Cyan: Green: Existing buildings or structures, within or external to the site, to be retained Canopies and brise soleil on existing buildings The proposed development
Overshadowing In the case of the proposed development, and given the absence of existing residential dwellings, the relevant space for assessment of overshadowing and sunlight exposure is the Point Village Square. At present, Point Village Square comprises two connected parts that to the north of the 3Arena and the space to the east of the 3Arena that leads down to North Wall Quay. The proposed development, including the Exo Building and public realm works, will create better definition and sense of enclosure to the Point Village Square while retaining the two connected parts with related characters. For the purposes of overshadowing assessment, the solar exposure on the northern and eastern parts are treated separately as Area A and Area B indicated on Figures D1 to D6 below. Solar Exposure on the ground on 21 st March for both the Existing and Proposed situation is shown in Figure D1 below. It is clear from Figure D1, that on the 21 st March, both areas can currently receive greater than two hours of sunshine over almost the entire of each area. Post construction, the sunlight exposure in the area immediately in front of the northern face of the 3Arena will be reduced to between zero and two hours. This will be as a result of the northern part of the Exo Building extending into Point Village Square and obstructing early morning sunshine. Post construction, Area B will experience a reduction in the central portion to between 1 and 2 hours, and this will be as a result of the middle core of the Exo building coming down to ground level. The sunlight lost in Area B will also be early morning sunlight. Similarly, although not strictly required under BRE209, the results for 21 st June and 21 st December are provided in Figures D2 and D3 respectively. For 21 st June, Figure D2 shows that the two hour threshold is effectively not breached at all, before or after construction. For December, Figure D3 shows that Area A currently receives from zero to one hour in the space immediately in front of the northern façade of the 3Arena and extending approximately half of the way across Point Village Square, while Area B receives more than two hours. Post construction, the areas receiving from zero to one hour, and from one to two hours, will increase to include approximately 60% of Area A and 30% of Area B. It should be noted however that the sunlight lost will all be early morning sunlight when the amenity of the area as a public space is less relevant. Shadow Plans are provided for 21 st March, for Existing and Proposed, in Figures D4, D5 and D6 below for 09:00am, 12:00 noon, and for 3:00pm respectively. Shadows resulting from existing buildings or structures are shown in red, while those resulting from proposed structures are shown in blue. The figures reflect the findings of the Sunlight Exposure findings, in that the proposed development will result in additional overshadowing on Point Village Square in the morning hours, and that from approximately 1:00pm, there will effectively be no additional overshadowing on Point Village Square over and above existing levels of overshadowing. It is considered that the public space of Point Village Square, both to the north and east of the 3Arena, will experience some overshadowing, but given the public space nature of the area and the predominantly afternoon and evening use of the space, such impacts will be slight.
Figure D1: Sunlight Exposure on 21 st March As Existing (top) As Proposed (bottom)
Figure D2: Sunlight Exposure on 21 st June As Existing (top) As Proposed (bottom)
Figure D3: Sunlight Exposure on 21 st December As Existing (top) As Proposed (bottom)
Figure D4: Shadow Plans for 21 st March at 09:00am As Existing (top) As Proposed (bottom)
Figure D5: Shadow Plans for 21 st March at 12:00 noon As Existing (top) As Proposed (bottom)
Figure D6: Shadow Plans for 21 st March at 3:00pm As Existing (top) As Proposed (bottom)
5. CONCLUSION The Proposed development is located at the eastern end of the existing North Lotts area, and as such, there are no potentially sensitive buildings or spaces to the east of the site. Additionally, the closest residential dwellings to the proposed development are at Castleforbes Square approximately 200m to the west and as such, is sufficiently far away not to be of concern in relation to the proposed development. Therefore, there are no impacts on residential dwellings at all, and the impacts that will arise will be in the form of partial shading and obstruction of daylight on a combination of retail, hotel and commercial uses. As can be seen from the assessment above, the inherent design characteristics of those buildings is to substantially shade sunlight and filter daylight to suit their designed uses. By virtue of the relative location of the proposed building and its orientation, any such impacts will be restricted to the morning time only, and all afternoon and evening shadows arising from the development will fall east of any existing built development. Point Village Square, the public space at Point Village, will experience some additional overshadowing, but the residual access to sunlight will be greater than the recommendations set out in BRE209. The lossof sunlight will be limited to the morning hours only when the public spaces are less used. It should also be noted that the overall development proposals are designed to enhance the public realm by creating a greater sense of enclosure, together with animated frontage, revised pedestrian permeability and new elements of visual interest all of these factors will contribute to the quality and amenity of the public space and it is considered that any increase in overshadowing will be more than compensated for by the other benefits accruing to the public space and its amenity value. The impacts on Daylight, Sunlight and Overshadowing are slight to none, and are considered appropriate in an urban context.