SWANSEA CENTRALswanseacentral.info/assets/daylight-and-sunlight...BS 8206 Part 2: 2008 Code of...

30 JANUARY 2017

FOR

PREPARED BY

PETER BRETT ASSOCIATES

© ALL RIGHTS RESERVED. MAY NOT BE USED, REPRODUCED OR MODIFIED WITHOUT EXPRESSED PERMISSION IN WRITING.

SWANSEA CENTRALDAYLIGHT AND SUNLIGHT ASSESSMENT

draft

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SWANSEA CENTRAL – DAYLIGHT AND

SUNLIGHT STATEMENT

JAN 2017

DAYLIGHT AND

SUNLIGHT STATEMENT

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1 Introduction 1.1 Introduction

1.1.1 This report is for submission as part of an outline planning application for Swansea Central and demonstrates that daylight and sunlight matters have been considered from the outset in accordance with planning policy.

1.1.2 The project comprises the redevelopment of part of Swansea City Centre by the Council of the City and County of Swansea, to provide mixed-use accommodation across two sites (north and south), which are separated by Oystermouth Road.

1.1.3 The outline planning application (with all matters reserved) is for the refurbishment, alteration and / or demolition of all existing buildings / structures on the site (except St Mary’s Church and St David’s Church) and redevelopment of site with indicative access / layout and scale parameters on the north site of a maximum of 1 to 7 storeys and maximum new floorspace of 84,050 sqm comprising retail / commercial / office use (Classes A1/A2/A3/B1) residential (Class C3), non-residential institution (Class D1) and leisure (Class D2), multi storey car park and redevelopment of south site of a maximum of 40,700 sqm of floorspace comprising a new arena (Class D2), up to 13 storey hotel / residential building (Class C1/ C3), food and drink (Class A3), undercroft car park, potential energy centre. Across both sites, the provision of associated new public open space / public realm and landscaping, new pedestrian and vehicular access and servicing arrangements (including a pedestrian bridge link across Oystermouth Road), provision of new bus stops on Oystermouth Road, new pedestrian access through existing arches along Victoria Quay, relocation of Sir H Hussey Vivian statue, earthworks, and plant.

2 Planning policy context 2.1 Planning policy context

2.1.1 Planning policy relevant to the proposed development is summarised in Table 1.

Table 1: Planning policy context

Document Policy/reference Quantitative targets

National (Welsh Assembly)

The Wales Spatial Plan (2008

Update) None None

Local (The City and County of Swansea Council)

Unitary development plan

(November 2008) None None

Local Development Plan

2010-2025 Deposit Plan (July

2016)

Policy PS2: placemaking and

place management None

Non Retail Uses in Swansea

City Centre SPG (October

2010)

None None

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City Centre Strategic

Framework SPG None None

Tall Buildings Strategy SPG

(October 2008) Page 22 None

Swansea Bay Strategy SPG

(February 2008) None None

2.1.2 The Local Development Plan (LDP) represents emerging policy. Consultation on the Deposit LDP closed on 31 August 2016. The Deposit LDP is due to be submitted to the Welsh Government for independent examination during 2017, with a view to adoption in January 2018.

3 Methodology 3.1 Methodology

3.1.1 The key reference document is Site Layout Planning for Daylight and Sunlight - A Guide to Good Practice, which is widely recognised as defining good practice and is used extensively in drafting planning policy and in assessing planning applications. It is intended to be used in conjunction with BS 8206 Part 2: 2008 Code of Practice for Daylighting and Lighting Guide 10: Daylighting and Window Design, and its guidance is intended to fit in with their recommendations. These documents are referred to as the BRE Guide, BS 8206-2 and CIBSE LG10 respectively hereafter.

3.1.2 There are two measurements of daylight or sunlight referred to in the BRE Guide and used in this report.

Table 2: Measurements of daylight or sunlight

Measurement Description

Vertical Sky Component

(VSC)

Measurement of the total amount of skylight available on

the face of a building

Defined as the ratio of the direct sky illuminance falling on

the vertical wall at a reference point, to the simultaneous

horizontal illuminance under an unobstructed sky

The ratio is usually expressed as a percentage, with the theoretical maximum value being almost 40 % for a

completely unobstructed wall

Probable Sunlight Hours

(PSH)

Long-term average of the total number of hours during a

year in which direct sunlight reaches the unobstructed

ground (when clouds are taken in to account)

3.1.3 The BRE Guide is intended to provide advice to building designers and planners, and does not set mandatory standards or thresholds. It also states that the guidelines should be interpreted flexibly in conjunction with other site layout considerations.

3.1.4 Table 3 shows which aspects of daylight and sunlight assessment are covered in this report.

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Table 3: Daylight and sunlight assessments undertaken

Property type Daylight self-

assessment

Sunlight self-

assessment

Daylight impact

assessment

Sunlight impact

assessment

Dwellings Yes Yes Yes N/A

Non-dwellings Yes N/A Yes Yes

Gardens & open

spaces N/A Yes N/A Yes

3.1.5 At outline planning stage, the proposed development identifies minimum and maximum parameters for the buildings’ massing. This report is based on the maximum parameters, which are assumed to represent the worst-case scenario in terms of daylight and sunlight.

Table 4: Calculation parameters

Aspect Description

Geometry Drawings and 3-d modelling provided by Acme

Maximum parameters

Glazing performance (light transmittance)

Not applicable

Surface reflectance

Default:

Walls – 37 %

Roof – 25 %

Landscape – 25 %

Software

IES Virtual Environment (version 2016.0.1.0)

Daylight: Radiance module

Sunlight: SunCast module

3.1.6 For impact assessment existing (baseline) and proposed circumstances are compared. This is generally an appropriate approach for most urban locations where there are existing buildings on a site which is to be redeveloped. When dealing with infill sites (currently cleared land between developed plots) or sites with a particularly low level of existing development, the impact of new buildings often does not meet good practice. This is because existing neighbouring properties benefit from levels of daylight and sunlight that are unusual in, and not always commensurate with, urban areas. In these circumstances strict application of the good practice criteria is therefore not usually appropriate.

3.1.7 Figure 1 and Figure 2 show the existing and proposed circumstances respectively.

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Figure 1: Model of existing circumstances

Figure 2: Model of maximum parameters for proposed circumstances

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4 Daylight self-assessment

4.1 Design criteria

4.1.1 The BRE Guide proposes the following design criteria in respect of the potential for good daylight.

4.1.2 Obstructions can limit access to light from the sky. This can be checked by measuring the angle of visible sky (θ), angle of obstruction or VSC at the centre of the lowest window where daylight is required. If VSC is:

at least 27 % (θ is greater than 65 °, obstruction angle less than 25 °) conventional window design will usually give reasonable results.

between 15 % and 27 % (θ is between 45 ° and 65 °, obstruction angle between 25 ° and 45 °) special measures (larger windows, changes to room layout) are usually needed to provide adequate daylight

between 5 % and 15 % (θ is between 25 ° and 45 °, obstruction angle between 45 ° and 65 °) it is very difficult to provide adequate daylight unless very large windows are used.

Less than 5 % (θ less than 25 °, obstruction angle more than 65 °) it is often impossible to achieve reasonable daylight, even if the whole window wall is glazed.

4.1.3 For the outline planning application, the purpose of the assessment is to demonstrate the potential for good daylighting. Therefore, the focus is on quantifying the daylight falling on to the facades, rather than the penetration of daylight in to the building. Assessment of actual interior daylighting, typically based on the ADF, room depth and the position of the no-sky line, would be undertaken as part of the detailed, reserved matters application(s) for each Development Zone.

4.2 Calculations

4.2.1 Figure 5 to Figure 29 inclusive shows VSC for all of the proposed development’s primary elevations. There are two versions of each image: a plain monochrome rendering in the left-hand column; and false colour VSC contours in the right-hand column. Figure 3 shows the location of the ‘eye’ position and Figure 4 shows the key for each of these images.

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Figure 3: Location of ‘eye’ position for views 1 to 27

Figure 4: Key to views 1 to 25 (number represents VSC, so higher values demonstrate greater daylight availability)

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Figure 5: View 1 (proposed circumstances)




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4.2.2 There is one instance of VSC of less than 5 %, which occurs where there is a narrow gap between the maximum parameters of DZ1a and the existing Quadrant Shopping Centre; refer to Figure 9. However, the maximum parameters are intended to facilitate retail uses having a rear elevation and service yard.

4.2.3 Under the maximum development parameters, it is not likely to be possible to achieve reasonable daylighting in single-aspect rooms on the part of this elevation where the existing shopping centre is in close proximity. Therefore, were this development zone to accommodate dwellings above retail uses, daylight availability could be mitigated through design development, for example by articulating the massing, in accordance with the Design Principles.

4.2.4 There are several instances of VSC of between 5 % and 15 %, which are illustrated in the annotated images below (see Figure 32 to Figure 36). In these circumstances, based on the maximum development parameters, it is very difficult to provide adequate daylight unless very large windows are used. However, the VSC is generally only less than 15 % on the lowest storey of these facades

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and around internal corners. This could be mitigated through design development by allocating these parts of the development to consented use classes that do not generally have a requirement for good daylight, for example retail.

4.2.5 In three cases, this occurs where there are new ‘streets’ between the proposed development zones. The three other instances are due to proximity of the existing buildings: Excelsior building to DZ2a; Quadrant Shopping Centre to DZ1a; and Llanfair building to DZ2a.

Figure 32: View 7 (proposed circumstances) with point VSC measurements

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4.2.6 In each of the five instances where a VSC of less than 15 % occurs, a greater part of these facades

has a VSC of between 15 % and 27 %. There are also a further six instances of VSC in this range. Figure 38 shows one example.

4.2.7 In four cases, this occurs where there are new ‘streets’ between the proposed development zones. Otherwise, one case is due to the proximity of the Excelsior building to DZ2d and the other occurs where there are internal corners on DZ1a.

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4.2.8 Otherwise, the facades of the proposed blocks have a VSC of at least 27 %.

4.3 Summary

4.2.9 In summary, for most of the proposed development, daylight availability is sufficiently good that conventional window design is likely to provide good internal daylight. The exceptions are at low level, where other buildings are in fairly close proximity. In these circumstances, the likely use class would be shops and retail outlets, which do not generally have a requirement for good daylight. Where this is not the case, special measures (larger windows, shallow-plan rooms, articulated massing allowing dual aspect windows) could be needed to ensure adequate daylight.

5 Sunlight self-assessment 5.1 Design criteria

BUILDINGS

5.1.1 The BRE Guide proposes the following design criteria for dwellings.

In general, a dwelling or non-domestic building which has a particular requirement for sunlight, will appear reasonably sunlit provided:

at least one main window wall faces within 90 º of due south; and

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the centre of at least one window to a main living room can receive 25 % of annual probable sunlight hours, including at least 5 % of annual probable sunlight hours in the winter months between 21 September and 21 March.

Where groups of dwellings are planned, site layout design should aim to maximise the number of dwellings with a main living room that meets the above recommendations.

5.1.2 For the outline planning application, the purpose of the assessment is to demonstrate the potential for good sunlight. Therefore, the focus is on quantifying the sunlight falling on to the facades, rather than the penetration of sunlight in to the building. Assessment of actual sunlight availability for each room, based on probable sunlight hours for the winter and annual periods respectively, would be undertaken as part of the detailed, reserved matters application(s) for each development zone.

OPEN SPACE

5.1.3 The BRE Guide proposes the following design criteria for open space.

5.1.4 The availability of sunlight should be checked for all open spaces where it will be required. This would normally include:

Gardens, usually the main back garden of a house

Parks and playing fields

Children’s playgrounds

Outdoor swimming pools and paddling pools

Sitting out areas such as though between non-domestic buildings and in public squares

Focal points for views such as a group of monuments of fountains.

5.1.5 As a check, it is recommended that at least half of the amenity areas listed above should receive at least two hours of sunlight on 21 March. It is instructive to draw the ‘two hours sun contour’ which marks this area on plan, because the use of specific parts of a site can be planned with sunlight in mind. This could include reserving the sunniest parts of the site for gardens and sitting out, while using the shadier areas for car parking (in summer, shade is often valued in car parks). If a detailed calculation cannot be carried out, and the area is a simple shape, it is suggested that the centre of the area should receive at least two hours of sunlight on 21 March.

5.1.6 For the outline planning application, the purpose of the assessment is to demonstrate the potential for good sunlight. Therefore, the focus is on checking that the centre of open spaces receives at least two hours of sunlight on 21 March. Detailed assessment of sunlight availability in open spaces, based on the ‘two hours sun contour’, would be undertaken as part of the detailed, reserved matter application for each development plot.

5.2 Calculations

BUILDINGS

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5.2.1 The proposed development does not feature any non-domestic buildings anticipated to have a particular requirement for sunlight, so the analysis focuses on the elevations of those buildings whose potential use include dwellings (planning use class C3). These elevations are identified in Figure 39.

5.2.2 Table 5 shows the annual and winter probable sunlight hours for these elevations. Since window positions are unknown at this stage, the figures represent an area-weighted average for the façade as a whole. In practice sunlight availability varies across the façade, generally improving with height.

Figure 39: References of elevations tested for sunlight availability

Table 5: Equivalent probable sunlight hours for the proposed development

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Facade Annual PSH Winter PSH

DZ1a-1 26.82 19.97

DZ1a-2 40.47 33.35

DZ1a-3 51.71 56.32

DZ1a-4 13.92 5.28

DZ1a-5 18.76 16.45

DZ2a-1 23.84 22.35

DZ2a-2 27.02 21.78

DZ2a-3 33.12 40.23

DZ2a-4 57.06 52.95

DZ2a-5 47.32 40.21

DZ2a-6 17.89 4.32

DZ2a-7 6.63 1.82

DZ2a-8 9.48 2.25

DZ2b-1 8.86 1.99

DZ2b-2 7.33 1.06

DZ2b-3 42.01 43.70

DZ2b-4 49.01 37.46

DZ2b-5 23.85 20.97

DZ2b-6 7.02 0.23

DZ3-1 20.15 13.87

DZ3-2 62.33 61.97

DZ3-3 63.09 71.48

DZ3-4 21.35 12.61

DZ3-5 10.58 4.72

DZ4c-1 24.16 10.91

DZ4c-2 26.02 12.56

DZ4c-3 42.05 36.05

DZ4c-4 78.24 93.55

DZ4c-5 46.13 49.42

5.2.3 Due to the site’s essentially flat topography and city centre location, with its attendant scale and density, it is unsurprising that not all facades benefit from good levels of solar exposure. Of the 29 facades analysed, 15 show good sunlight availability, when treated as a whole and subjected to the good practice tests. Facades that are either north-facing or in close proximity to other buildings have lower levels of solar exposure. However, there is significant variance across all facades.

5.2.4 To minimise breaches of the good practice recommendations, the use classes could be arranged such that dwellings (and any other accommodation having a particular requirement for sunlight) are arranged on the upper storeys with facades benefitting from good sunlight availability. Single-aspect dwellings with low solar exposure could be avoided, unless there are compensating measures, such as a good view of St David’s Church, St Mary’s Church or the wider city.

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OPEN SPACE

5.2.5 The proposed development incorporates new open space around St David’s Church. Figure 41 to Figure 52 are shadow diagrams for the equinox. Figure 40 shows the viewpoint for these images and the redline indicates the site boundary for the purposes of the planning application.

5.2.6 These show that between about 10:00 and 15:00 a substantial proportion of the area to the northwest of the church receives sunlight. Even if the development plots around St David’s Church are built out to the maximum parameters, it is likely that the good practice recommendations could be met. As the sunniest part of the open space, the area to the northwest of the church would be suitable for a garden and/or seating.

Figure 40: Key to sun path diagram

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Figure 41: 07:00 March 21st








2 1 M a r 0 7 : 0 0 2 1 M a r 0 8 : 0 0

2 1 M a r 0 9 : 0 0 2 1 M a r 1 0 : 0 0

2 1 M a r 1 1 : 0 0 2 1 M a r 1 2 : 0 0

2 1 M a r 1 3 : 0 0 2 1 M a r 1 4 : 0 0

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6 Daylight impact assessment 6.1 Design criteria

6.1.1 The BRE Guide proposes the following design criteria.

If any part of a new building or extension, measured in a vertical section perpendicular to a main window wall of an existing building, from the centre of the lowest window, subtends an angle of more than 25 ° to the horizontal, then the diffuse daylighting of the existing building may be adversely affected. This will be the case if either:

the VSC measured at the centre of an existing main window is less than 27 %, and less than 0.8 times its former value;

the area of the working plane in a room which can receive direct skylight is reduced to less than 0.8 times its former value.

6.1.2 In this case compliance with the second criterion (direct skylight) has not been assessed as the internal layouts of the existing buildings were not available.

6.2 Calculations

6.2.1 Firstly, the potential for good daylight was tested. Figure 53 to Figure 74 inclusive show VSC contours plotted on the existing buildings’ elevations. The odd-numbered images in the left-hand column show the proposed circumstances and the even-numbered images in the right-hand

2 1 M a r 1 5 : 0 0 2 1 M a r 1 6 : 0 0

2 1 M a r 1 7 : 0 0 2 1 M a r 1 8 : 0 0

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column show the existing circumstances. Figure 3 shows the location of the ‘eye’ position for each of these images.

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Figure 53: View 1 (existing circumstances)








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6.2.2 These images were used to check the VSC at potentially affected locations under the existing and proposed circumstances. Sample point VSC measurements were used to estimate the range of VSC under both circumstances and to apply the good practice tests.

6.2.3 Two parts of the Excelsior building are affected by breaches of the good practice guidance. Firstly, on the lowest two floors, the rooms that face in to the courtyard/light-well bounded by DZ2a have VSC in the range 6-15 % under the existing circumstances, with reductions of typically 20-30 % under the proposed circumstances. Secondly on the lower three floors, under the proposed circumstances, the rooms directly opposite DZ2d would have a VSC in the range 20-30 %, which represent reductions of 15-40 % in comparison to the existing circumstances. (While the preliminary modelling does not take in to account the external balconies, the Excelsior building’s design appears to have incorporated compensating measures, in the form of large windows and glazed doors in these parts of the facade.)

6.2.4 Properties on Victoria Quay with rooms facing DZ4 would also be affected by breaches of the good practice guidance. At Squire Court the reduction in available daylight would be 10-40 %, resulting in VSC in the range 15-30 %. For York Court the reduction would be 30-40 %, resulting in VSC in the range 21-31 %. It is marginal whether the impact on Penryce Court would be significant. The impact on neither Anchor Court nor Dewsbury Court would breach the guidelines.

6.2.5 These buildings are three to five storeys high and accommodate predominantly residential dwellings. The results indicate that potentially significant impacts would likely be limited to the lower two levels. The ‘front’ elevations face on to Victoria Quay; the rear elevations are those potentially affected by the proposed development. The internal layouts of these buildings are not available via planning application search of the Council of the City and County of Swansea’s website but it appears that the properties are generally arranged with the primary living space(s) overlooking the marina and bedrooms and communal circulation space to the rear.

6.2.6 The calculations indicate that VSC on the east elevation of St David’s Church would be reduced by up to 40 %, taking the range to 20-28 % at ground floor level.

6.2.7 The south elevation of the LC Swansea Leisure Centre is essentially unaffected by the proposed development. On the west elevation, VSC would be reduced by around 40-60 %, bringing it in to 18-30 % range. Although this indicates a breach of the guidance on daylight availability, the pool hall benefits from extensive glazing on both elevations, so actual interior daylighting could remain satisfactory under the proposed circumstances.

6.2.8 Properties at nos. 10-12 St Mary’s Square are affected by breaches of the good practice guidance. These affect rooms on the first floor and part of the second floor, at the west end of no.12’s south elevation, and occur due to the increase in height associated with development zone DZ2a. However, even under the maximum parameters, the ground floor would benefit from better daylight availability, on account of the more generous spacing between the buildings. These properties accommodate a variety of use, including student residences and a clinic, which would benefit from good daylight.

6.3 Summary

6.2.9 Based on the maximum parameters, the modelling indicates some breaches of the guidance on daylight impact assessment in respect of the Excelsior building, properties on Victoria Quay, St David’s Church, the LC Swansea leisure centre and 10-12 St Mary’s Square. Potentially significant impacts could be mitigated through design development, primarily in the massing of buildings within DZ2a, DZ2d and DZ4c. Given the assessment is based on a ‘blocky’ parameter plan, representing the maximum bulk and massing of proposed buildings, there is considerable scope for refinement such that impacts are avoided or limited.

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7 Sunlight impact assessment 7.1 Design criteria

BUILDINGS

7.1.1 The BRE Guide proposes the following design criteria for buildings.

7.1.2 If a living room of an existing dwelling has a main window facing within 90 ° of due south, and any part of a new development subtends an angle of more than 25 ° to the horizontal measured from the centre of the window in a vertical section perpendicular to the window, then the sunlighting of the existing dwelling may be adversely affected. This will be the case if the centre of the window:

receives less than 25 % of annual probable sunlight hours, or less than 5 % of annual probable sunlight hours between 21 September and 21 March; and

receives less than 0.8 times its former sunlight hours during either period; and

has a reduction in sunlight received over the whole year greater than 4 % of annual probable sunlight hours.

OPEN SPACE

7.1.3 The BRE Guide proposes the following design criteria for open space.

It is recommended that for it to appear adequately sunlit throughout the year, at least half of a garden or amenity area should receive at least two hours of sunlight on 21 March. If as a result of new development an existing garden or amenity area does not meet the above, and the area which can receive two hours of sun on 21 March is less than 0.8 times its former value, then the loss of sunlight is likely to be noticeable.

7.2 Calculations

BUILDINGS

7.2.1 No existing dwellings that could be potentially adversely affected by the proposed development were identified.

7.2.2 The pool hall at the west end of the LC Swansea Leisure Centre currently benefits from good sunlight. This building type would not normally be considering as having a requirement for sunlight but nonetheless the impact of the proposed development has been assessed. Since the west and south elevations are heavily glazed, the impact on both has been assessed.

7.2.3 Table 6 and Table 7 shows annual and winter sunlight availability for the existing and proposed circumstances respectively.

Table 6: Annual sunlight availability for existing and proposed circumstances

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Location Annual PSH existing (%)

Annual PSH proposed (%)

Annual PSH reduction (%)

Ratio

(proposed: existing)

SC Leisure Centre

South elevation 74.1 70.7 3.4 0.95

West elevation 63.8 24.9 38.9 0.39

Table 7: Winter sunlight availability for existing and proposed circumstances

Location Winter PSH

existing (%)

Winter PSH

proposed (%)

Winter PSH

Reduction (%)

Ratio

(proposed:

existing)

SC Leisure Centre

South elevation 87.0 79.5 7.5 0.91

West elevation 73.8 28.8 45.0 0.39

7.2.4 Taken in isolation, for the west elevation the reduction in sunlight availability would breach the good practice recommendations, on account of it receiving 24.9 % of annual probable sunlight hours, marginally below the 25 % threshold. However, the pool hall receives sunlight from both south and west elevations, and overall the recommendations are met, i.e. the impact of the proposed development is not considered significant.

OPEN SPACE

7.2.5 The proposed development potentially affects sunlight availability to two existing open spaces: around St Mary’s Church; and the amphitheatre to the south of the LC Swansea Leisure Centre. Both areas are covered by the shadow diagrams for the equinox presented in section 5 (Figure 41 to Figure 52).

7.2.6 These show that the areas to the north, west and south of St Mary’s Church would all receive more than two hours of sunlight of the equinox. Similarly, more than half of the amphitheatre receives considerably more than two hours of sunlight of the equinox. Therefore, any impact of the proposed development on these areas is not considered significant.

8 Conclusions 8.1 Conclusions

8.1.1 Daylight and sunlight within and around the proposed development has been assessed, based on the guidance set out in Site Layout Planning for Daylight and Sunlight - A Guide to Good Practice.

8.1.2 The assessment is based on the maximum development parameters, which are assumed to represent the worst-case scenario in terms of daylight and sunlight. Design development would offer opportunities to further improve the daylight and sunlight penetration within and around the site.

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8.1.3 For the outline planning application, the purpose of the daylight self-assessment is to demonstrate the potential for good daylighting. Therefore, the focus is on quantifying the daylight falling on to the facades, rather than the penetration of daylight in to the building. Assessment of actual interior daylighting, typically based on the ADF, room depth and the position of the no-sky line, would be undertaken as part of the detailed, reserved matters application(s) for each development zone.

8.1.4 In summary, for most of the proposed development, daylight availability is sufficiently good that conventional window design is likely to provide good internal daylight. The exceptions are at low level, where other buildings are in fairly close proximity. In these circumstances, the likely use class would be shops and retail outlets, which do not generally have a requirement for good daylight. Where this is not the case, special measures (larger windows, shallow-plan rooms, articulated massing allowing dual aspect windows) could be needed to ensure adequate daylight.

8.1.5 For the outline planning application, the purpose of the sunlight self-assessment is to demonstrate the potential for good sunlight. Therefore, the focus is on quantifying the sunlight falling on to the facades, rather than the penetration of sunlight in to the building. Assessment of actual sunlight availability for each room, based on probable sunlight hours for the winter and annual periods respectively, would be undertaken as part of the detailed, reserved matters application(s) for each development zone.

8.1.6 Due to the site’s essentially flat topography and city centre location, with its attendant scale and density, it is unsurprising that not all facades benefit from good levels of solar exposure. Of the 29 facades analysed, 15 show good sunlight availability, when treated as a whole and subjected to the good practice tests. Facades that are either north-facing or in close proximity to other buildings have lower levels of solar exposure. However, there is significant variance across all facades.

8.1.7 To minimise breaches of the good practice recommendations, the use classes could be arranged such that dwellings (and any other accommodation having a particular requirement for sunlight) are arranged on the upper storeys with facades benefitting from good sunlight availability. Single-aspect dwellings with low solar exposure could be avoided, unless there are compensating measures, such as a good view of St David’s Church, St Mary’s Church or the wider city.

8.1.8 The proposed development incorporates new open space around St David’s Church, which would likely meet the good practice recommendations for sunlight, even if the development plots around St David’s Church were built out to the maximum parameters. As the sunniest part of the open space, the area to the northwest of the church would be suitable for a garden and/or seating.

8.1.9 Based on the maximum parameters, the modelling indicates some breaches of the guidance on daylight impact assessment in respect of the Excelsior building, properties on Victoria Quay, St David’s Church, the LC Swansea leisure centre and 10-12 St Mary’s Square. Potentially significant impacts could be mitigated through design development, primarily in the massing of buildings within DZ2a, DZ2d and DZ4c. Given the assessment is based on a ‘blocky’ parameter plan, representing the maximum bulk and massing of proposed buildings, there is considerable scope for refinement such that impacts are avoided or limited.

8.1.10 With regard to sunlight, the proposed development would have no significant impacts on either existing buildings or open spaces requiring sunlight.

8.1.11 Overall, the proposed development has the potential to be acceptable at reserved matters stage, so there are no reasons in respect of daylight or sunlight for not approving the outline planning application.

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