Daylight & Sunlight Assessments of a Strategic Housing ...

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Daylight & Sunlight Assessments of a Strategic Housing Development at Mount St. Mary’s, Dundrum Road, Dublin 14.

Applicant: Winterbrook Homes (MSM) Ltd. Date: 27th April 2021

Prepared by John HealyMSc Environmental Design of Buildings

1 Rathmines Road Upper, Dublin 6, D06 Y5P5 tel 01 4965340 email [email protected] web digitaldimensions.ie Digital Dimensions Ltd trading as Digital Dimensions.

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1: Introduction

We, Winterbrook Homes (MSM) Ltd, intend to apply to An Bord Pleanála for planning permission for a strategic housing development at a site of approx. 1.6 ha at Mount Saint Mary’s and Saint Joseph’s, Dundrum Road, Dublin 14 (D14 P9P3 & D14 AH57).

The site consists of the former Middle House; the Small Hall; the Gate Lodge Bungalow; the former Residence Wing building; former Chapel, Oratory and Side Chapels; and associated ancillary outbuildings (Stables/Lockups and Workshops). Robert Emmet House (a protected structure, RPS. No. 18) is located immediately adjacent to the main development site.

The development will consist of a new residential and mixed use scheme to include apartments, a central public park, café, afterschool childcare facility, pedestrian routes and associated resident facilities and amenities. A detailed development description is now set out as follows:

The proposal provides for the demolition (total area of approx. 2,913.8 sq m) of (a) the existing buildings on site (ranging in height from 1 - 3 storeys) and (b) part of the granite wall along Dundrum Road. The existing Small Hall (approx. 170 sq m) is retained and reconfigured as part of the overall proposal.

The new development will provide for the construction of a new residential scheme of 231 no. apartment units in the form of 5 no. apartment blocks (Villas A to E) ranging in height from 4 to 10 storeys as follows:

• Villa A (4 storeys) comprising 40 no. apartments (23 no. 1 bed and 17 no. 2 bed units)• Villa B (4 - 5 storeys) comprising 37 no. apartments (14 no. 1 bed and 23 no. 2 bed units)• Villa C (5 - 6 storeys) comprising 40 no. apartments (11 no. 1 bed and 29 no. 2 bed units)• Villa D (5 - 10 storeys) comprising 80 no. apartments (51 no. 1 bed and 29 no. 2 bed units)• Villa E (4 - 6 storeys) comprising 34 no. apartments (16 no. 1 bed and 18 no. 2 bed units)

Each residential unit has associated private open space in the form of a terrace/balcony.

The existing Small Hall will be reconfigured to accommodate an Afterschool Childcare Facility of approx. 161 sq m. The proposal will also provide for a café of approx. 83 sq m at the ground floor of Villa E.

Residential amenity areas of approx. 308 sq m are proposed in the form of resident support services and concierge services of approx. 111 sq m at the ground floor of Villa A; a gym room of approx. 77 sq m at the ground floor of Villa D; and a glazed pavilion indoor social space of approx. 120 sq m at the fourth floor of Villa D. A roof garden residential amenity area of approx. 130 sq m is also proposed at the fourth floor of Villa D.

Works to the northern and eastern boundary of Robert Emmet House (a protected structure) include (a) the closing up of opes to the existing Small Hall; and (b) the partial removal of a link between the existing Middle House on site and the adjacent Robert Emmet House (a protected structure) at ground and first floor levels and the subsequent reconfiguration and retention of existing fire escape at ground floor level for this building on the eastern elevation.

Open space (approx. 8,200 sq m) is proposed in the form of (a) a central public park including formal gardens, lawns, play area and pedestrian and cyclist links (approx. 6,300 sq m) and (b) residential / communal open space (approx. 1,900 sq m) including the roof terrace at Villa D (approx. 130 sq m).

Basement areas (total approx. 3,372 sq m) are proposed on one level, below Villas A and B, and include parking areas, waste management and plant areas. An ESB substation (approx. 45.5 sq m) and café waste store (approx. 18 sq m) are also proposed at surface level.

A total of 118 no. car parking spaces (99 no. at basement level and 19 no. at surface level) are proposed. 20 no. spaces are reserved for Robert Emmet House (10 no. at basement level and 10 no. at surface level). 463 no. bicycle spaces (365 no. at basement level and 98 no. at surface level) and 4 no. motorcycle spaces are proposed (all at basement level).

The development shall be served via the existing vehicular access point from Dundrum Road. Upgrade works are proposed to this vehicular access point to facilitate the proposed development and to provide for improved access and egress for the overall development. New pedestrian and cyclist access points will be provided via Dundrum Road and Churchfields. Future pedestrian links to the Hawthorn Residential Estate can be facilitated subject to third party approval.

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The associated site and infrastructural works include provision for water services; foul and surface water drainage and connections; attenuation proposals; permeable paving; all landscaping works including tree protection, tree removal and new tree planting; green roofs; boundary treatment; internal roads and footpaths; and electrical services.

This analysis is carried out based on the drawings of Reddy Architecture and Urbanism.

1.1 Executive SummaryThe report assesses the impact of the proposed development for Daylight and Sunlight on the neighbouring buildings and the quality of daylight and sunlight to within the proposed development.

Impact on adjacent propertiesThere will be minimal impact to the daylight and sunlight to the adjacent dwellings with no perceivable reduction in either daylight or sunlight. There will be a minimal reduction in the sunlight to any of the adjacent amenity spaces. All areas assessed continue to meet or exceed the recommendations of the BRE guidelines.

Assessment of the quality of the proposed development.All the proposed units within the development will exceed the recommendations of the BRE guidelines for quality of Daylight with the apartments layouts which have been optimised for daylight and sunlight. The proposed amenity spaces will be bright well sunlit places and exceed the recommendations of the BRE guidelines.

Overall the results find that any impact on the adjacent residential structures would be minimal and imperceivable. There would be a good quality of daylight in the apartments analysed and the amenity areas would have sufficient sunlight to be bright and a pleasant spaces. The proposed development meets the recommendations of the BRE guidelines.

2: Methodology

2.1 Notes on the use of BS 8026-2 2008 and BRE guidance document (2011) Site layout planning for daylight and sunlight.Sustainable Urban Housing: Design Standards for New Apartments, Guidelines for Planning Authorities 2020 directs Planning authorities to have regard to quantitative performance approaches to daylight provision outlined in guides like the BRE guide ‘Site Layout Planning for Daylight and Sunlight’ (2nd edition) or British Standard BS 8206-2: 2008 – ‘Lighting for Buildings – Part 2: Code of Practice for Daylighting’. The standards for daylight and sunlight access in buildings (and the methodologies for assessment of same) suggested in both of these documents have been referenced in this Sunlight and Daylight Access Analysis. Neither the British Standard nor the BRE Guide set out rigid standards or limits. The BRE Guide is preceded by the following very clear warning as to how the design advice contained therein should be used: “The advice given here is not mandatory and the guide should not be seen as an instrument of planning policy; its aims is to help rather than constrain the designer. Although it gives numerical guidelines, these should be interpreted flexibly since natural lighting is only one of many factors in site layout design.” That the recommendations of the BRE Guide are not suitable for rigid application to all developments in all contexts is of particular importance in the context of national and local policies for the consolidation and densification of urban areas.

2.2 Daylight to the existing dwellingsThe site is analysed in plan, section and building use. Windows and amenity area are selected to test for impact from the proposed development.

BRE guidelines recommend that: “Loss of light to existing windows need not be assessed if the distance of each part of the new development from the existing window is three or more times its height above the centre of the existing window.”To check for this if part of a new building measured in a vertical section perpendicular to the main window wall of an existing building, from the centre of the lowest window, subtends an angle of more than 25º to the horizontal, then the diffuse light of the existing building may be adversely affected. If a window falls within a 45° angle both in plan and elevation with a new development in place then the window may be affected and should be assessed.

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For loss of daylight and sunlight to existing buildings BRE guidance document (2011) “Site layout planning for daylight and sunlight” is used and BS8206 Part 2:2008 Lighting for Buildings, Code of Practice for Daylighting.

For loss of light the report recommends calculation of the Vertical Sky Component. This is the ratio of direct sky illuminance falling on the outside window, to the simultaneous horizontal illuminance under an unobstructed sky. The standard CIE Overcast Sky is used and the ratio is usually expressed as a percentage. The maximum value is just under 40% for a completely unobstructed vertical wall. The Vertical Sky Component on a window is a good measure of the amount of daylight entering it.

The BRE guidelines set out a two stage assessment for the Vertical Sky Component: a) Where the Vertical Sky Component at the centre of the existing window exceeds 27% with the new development in place then enough sky light should still be reached by the existing window.

b) Where the Vertical Sky Component with the new development in place is both less than 27% and less than 0.8 times its former value, then the area lit by the window is likely to appear more gloomy, and electric light will be needed more of the time.

2.3 SunlightThe BRE guidelines recommend assessing the loss of sunlight to the main living rooms and conservatories if they have a window wall facing within 90° of due south. Kitchens and bedrooms are less important but care should be taken not to block too much sun. If the proposed development is fully north then sunlight need not be assessed.

The Annual Probable Sunlight Hours (APSH) is used to assess the quantity of sunlight for a given location. This is the total amount sunshine for a given location on an unobstructed horizontal surface taking cloud cover into account. To Assess the APSH and the Probable Sunlight Hours for winter statistical data from the Irish Meteorological Service is used. Table 1 shows the average sunlight hours for each month and the maximum possible without any cloud cover. This gives the factor of possible sunlight hours for each month.

Met Eireann Sunlight Hours Data Set 1981-2010Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

Average Sunlight Hours/ Day 1:54 2:45 3:36 5:32 6:44 6:40 5:17 5:13 4:16 3:17 2:10 1:44Average Sunlight Hours/ Month 58:54 77:00 111:36 166:00 208:44 200:00 163:47 161:43 128:00 101:47 65:00 53:44 1496.25Total Available Sunlight Hours 252 265 358 412 488 485 496 451 375 320 250 248 4383Probable Sunlight Hours Ratio 23.37% 29.06% 31.17% 40.29% 42.77% 41.24% 33.02% 35.86% 34.13% 31.81% 26.00% 21.67% 34.14%

Table 1: Average monthly sunlight hours recorded at Dublin Airport - Data set 1981-2010

The BRE guidelines recommend that the centre of a window or 1.6m above ground for a door be assessed and receive at least 25% of the APSH and at least 5% during the period of 21st September to 21st March. If the available APSH is less than this then it should not be reduced below 0.8 times its former value or noticeable loss of sunlight may occur.

2.4 Sunlight to gardens and open spacesFor calculations of sunlight analysis it is general practice to use March 21 and the recommendations of the BRE guidance document (2011) “Site layout planning for daylight and sunlight”. P.J Littlefair, in relation to Gardens and open spaces section 3.3.17 state:

“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. If a detailed calculation cannot be carried out, it is recommended that the centre of the area should receive at least two hours of sunlight on 21 March.”

2.5 Daylight in the proposed development. The proposed project is analysed in plan & section, and building use. The rooms are assessed for Average Daylight Factor (ADF).

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2.6 Environmental impact assessmentThe BRE guidelines sets out criteria for classification for assessment of impact where a new development affects a number of existing buildings or open spaces. The guide does not give a specific range or percentages but sets out parameters set out below.

“Where the loss of skylight or sunlight fully meets the guidelines in this book, the impact is assessed as negligible or minor adverse. Where the loss of light is well within the guidelines, or only a small number of windows or limited area of open space lose light (within the guidelines), a classification of negligible impact is more appropriate. Where the loss of light is only just within the guidelines, and a larger number of windows or open space area are affected, a minor adverse impact would be more appropriate, especially if there is a particularly strong requirement for daylight and sunlight in the affected building or open space.

Where the loss of skylight or sunlight does not meet the guidelines in this book, the impact is assessed as minor, moderate or major adverse. Factors tending towards a minor adverse impact include: • only a small number of windows or limited area of open space are affected • the loss of light is only marginally outside the guidelines • an affected room has other sources of skylight or sunlight • the affected building or open space only has a low level requirement for skylight or sunlight • there are particular reasons why an alternative, less stringent, guideline should be applied.

Factors tending towards a major adverse impact include: • a large number of windows or large area of open space are affected • the loss of light is substantially outside the guidelines • all the windows in a particular property are affected • the affected indoor or outdoor spaces have a particularly strong requirement for skylight or sunlight, eg a living room in a dwelling or a children’s playground.

Beneficial impacts occur when there is a significant increase in the amount of skylight and sunlight reaching an existing building where it is required, or in the amount of sunlight reaching an open space.

Beneficial impacts should be worked out using the same principles as adverse impacts. Thus a tiny increase in light would be classified as a negligible impact, not a minor beneficial impact.”

A flexible approach should be taken when assessing the impact with daylight and sunlight being one of many factors that influence the environment when planning a new development.

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Figure 1: Existing Site Plan.

3: Daylight to adjacent buildings.

Buildings to be demolished

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The site contains former institutional buildings of 1-3 Storeys, most of which are to be demolished. The protected structure, Emmet House and the adjoining single storey building to the rear, will be retained. Churchfields housing estate surrounds the site to the North and East. There are sports grounds to the South and the Dundrum road to the West with houses facing the site.

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Figure 2: Aerial view of site.

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Figure 3: Proposed site plan showing the zone of influence and sections through window wall of adjacent residential properties.

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3.1 Preliminary assessment of adjoining dwellings The BRE guideline recommends that loss of light to existing windows need not be assessed if the distance of each part of the new development from the existing window is three or more times its height above the centre of the existing window. The zone of influence 3 times the height of the proposal is plotted in Figure 3 in yellow.

Section planes perpendicular to the window wall of the properties facing the proposed development are indicated in blue. The planes at locations A-H extend and intersect the proposed development. Sections at these locations are plotted in Figures 4 & 5.

The document also states that if part of a new building measured in a vertical section perpendicular to the main window wall of an existing building, from the centre of the lowest window, subtends an angle of more than 25º to the horizontal, then the diffuse light of the existing building may be adversely affected. If a window falls within a 45° angle both in plan and elevation with a new development in place then the window may be affected and should be assessed.

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Figure 4: Sections through the window wall of the adjacent residential properties.

Villa B

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68 Churchfields

67 Churchfields

27 Churchfields

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Emmet House

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Figure 5: Sections through the window wall of the adjacent residential properties.

Villa DVilla E

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1 Coolnahinch, Dundrum Rd

3.2 DiscussionLocations A, B C and D: The 25º line would be subtended by the proposed development, indicating further assessment required.

Locations E, F and G: The 25º line is not subtended by the proposed development, indicating any reduction in available daylight is negligible and no further assessment required.

Location H: The 25º line would be subtended by the proposed development, indicating further assessment required.

3.3 ConclusionThe houses at Churchfields and Coolnahinch require further detailed assessment. For completeness all the houses adjacent to the proposed development within the zone of influence will be assessed in detail for the Vertical Sky Component (VSC) as recommended in the BRE guidelines.

30 St. Lukes Crescent

Villa DVilla E

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Figure 6: No.68 Churchfields - indicating VSC and APSH test points.

4: Detailed assessment to adjoining dwellings

Following the preliminary analysis the windows in No.s 14 - 30 Churchfields, No.s 44, 67 & 68 Churchfields, No.s 29 & 30 St. Lukes Crescent, Chandos and No.s 1 & 2 Coolnahinch, Dundrum Road were assessed for their Vertical Sky Component (VSC). The BRE guidelines recommends assessing adjacent dwellings for the Vertical Sky Component where there is a potential loss of daylight identified in the preliminary assessment. The BRE guideline recommends that if a window retains a VSC in excess of 27% with the proposed development in place then it will still receive enough daylight. If the existing VSC is below 27% or is reduced below 27% and below 0.8 times its former value then the diffuse light maybe adversely affected.

Test points representing window in the dwellings at locations identified in Section 3.3 are indicated in Figures 6 - 12. The BRE guidelines recommend assessing the Vertical Sky Component (VSC) to adjacent properties, where the preliminary assessment indicates a further assessment is required. The Annual Probable Sunlight Hours will also be assessed.

Window locations are represented as accurately as possible and are determined based on available information from Architectural and survey drawings, Local authority planning records, Google earth and on site observation. Access to private rear gardens was not possible and any omissions or inaccurate window locations are unintentional.

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Vertical Sky ComponentLocation Use/ Assumed

UseVertical Sky Component Recommended Value > 27%

Ratio: Proposal to Existing Recommended > 80%

Meets criteria of >27% VSC Or <27% but >80% Existing ValueExisting % Proposed %

68 Churchfields

1 Living room 29.2 28.1 96.4% Meets criteria

2 Family room 34.9 32.7 93.9% Average84.8%

*Dual AspectMeets criteria3 Family room 30.9 21.0 68.2%

4 Kitchen/ Dining 30.2 27.9 92.4% Average93.5%

*Dual AspectMeets criteria6 Kitchen/ Dining 34.7 32.8 94.6%

7 Bedroom 35.7 35.2 98.4% Meets criteria


9 Bedroom 32.0 29.3 91.6% Average77.9%

**Dual AspectMeets criteria10 Bedroom 36.2 23.2 64.2%



* The guidelines recommends where a room has 2 or more windows the average all the windows should be used.** Windows that retain a VSC in excess of 27% will not perceive a reduction in daylight availability.

Table 2: Vertical sky component for windows adjacent residential properties

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Figure 8: No.67 Churchfields - Indicating VSC and APSH test points.

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67 Garden Space

Vertical Sky ComponentLocation Use/ Assumed Use Vertical Sky Component Recommended

Value > 27%Ratio: Proposal to Existing Recommended > 80%

Meets criteria if >27% VSC or <27% but >80% Existing ValueExisting % Proposed %

67 Churchfields

13 Kitchen 34.8 32.1 92.4% Meets criteria

14 Study 30.2 30.0 99.2% Meets criteria

15 Family room 33.3 31.7 95.1% Meets criteria




19 Bathroom 36.0 32.3 89.7% Meets criteria

20 Landing 36.7 25.5 69.5% Meets criteria




130 Garden Room 27.0 25.2 93.3% Average87.3%

Meets criteria

131 Garden Room 31.1 25.5 81.2% Meets criteria

44 Churchfields






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Figure 7: No.67 Churchfields - Indicating VSC and APSH test points.



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No. 30

Figure 9: No.s 25 - 30 Churchfields - Rear view of model, locating VSC and APSH test points.

No. 29

No. 28No. 27

No. 25 No. 26




No.s 29 & 30 Churchfields






34 Dining 26.5 22.9 86.6% Meets criteria



No.s 25 - 28 Churchfields



















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Figure 10: No.s 17- 24 Churchfields - Rear view of model, locating VSC and APSH test points.

No. 24No. 23

No. 22No. 21No. 18

No. 19

No. 17

No. 20








































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No. 16

No. 14No. 15

Figure 11: No.s 14 - 16 Churchfields, No.s 29 & 30 St. Lukes Crescent - indicating VSC and APSH test points.

















No.s 29 & 30 St. Lukes Crescent







No. 30 No. 29

No.s 29 & 30 St. Lukes CrescentNo.s 14 - 16 Churchfields



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No. 2No. 1

Figure 12: Chandos, No.s 1 & 2 Coolnahinch -indicating VSC and APSH test points.

Chandos




Chanos, Dundrum Road







No.s 1 & 2 Coolnahinch






114 Bedroom 37.9 34.2 90.4% Meets criteria* The guidelines recommends where a room has 2 or more windows the average all the windows should be used.** Window retains a VSC in excess of 27% and no reduction in daylight availability will be perceived.


4.1 DiscussionAll the windows to the adjoining dwellings facing the proposed development were tested in detail. There is a minor reduction to the available daylight to some of the windows but all the windows either retain a VSC in excess of 27% or are not reduced below 80% of their former value if less than 27% VSC. In the case of a dual aspect room, it is sufficient that if one window retains a VSC in excess of 27% there will be no perceived loss of light or the average of the number of windows retains a VSC in excess of 80% of the existing value.

The assessment of the VSC is a measurement at a point at the centre of each window to determine the portion of the sky visible to the point and window. The assessment does not take into account window size, room depth and the interior finishes to the room. Even if there is a reduction below the values set out in the BRE guidelines there may not be a noticeable reduction in available daylight.

4.2 ConclusionThe loss of light to all the windows assessed is well within the recommendations of the BRE guidelines and the proposed development meets the recommendations of the BRE Guidelines and BS8206 Part 2:2008 Lighting for Buildings Code of Practice for Daylighting. Any reduction to the daylight in neighbouring dwellings would be imperceptible and any impact will be negligible.

No.s 1 &2 Coolnahinch

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Figure 13: View of Emmet House and of the model locating VSC test points.

4.3 Detailed assessment of Emmet House. Emmet House is a protected structure, 2 storeys over lower ground level and is currently in commercial use. The BRE guidelines does not set out specific requirement for daylight in rooms with commercial use. The windows that face the proposed development were assessed for impact on their VSC. Test points locations are indicated in Figure 13 and the results are displayed in Table 8 below.

Vertical Sky ComponentLocation Use Vertical Sky Component

Recommended Value > 27%Ratio: Proposal to Existing Recommended > 80%

Meets criteria of >27% VSC Or <27% but >80% Existing ValueExisting % Proposed %

115 Commercial 29.7 19.9 67.2% Minor impact


117 Commercial 24.1 19.9 82.4% Meets criteria













Table 8: Vertical sky component for windows in Emmet House.

4.4 Discussion4 of the 15 windows are below 80% of their former value. Windows 115 and 116 most likely serve the same room and have a window facing away from the proposed development (as can be seen in figure 13) on a different elevation which would average at 80% of the existing VSC value for the cumulative of the 3 windows. The same applies to windows 120 and 121. Five of the windows would have an increase in available access to light from the sky.

4.5 ConclusionThe majority of windows meet the recommendations of the BRE guidelines. 4 of the windows are reduced below marginally below 80% of their existing value but there is an increase availability to 5 windows. The building meets the recommendations of the BRE guidelines and any impact will be negligible.

DRAFT

17

5: Sunlight in Adjoining Residential Living Areas

5.1 Annual Probable Sunlight HoursThe BRE guidelines recommends assessing window walls for the APSH that face within 90° of due South. The houses that this applies to are No.s 14 to 30, 44, 67 & 68 Churchfields. For a proposed development to have a noticeable impact on the annual Probable Sunlight Hours the value need to be reduced below the recommended 25% annual or 5% in the winter period from September to March. If the value is either below this to begin with or is reduced below this then it should not be reduced below 80% of its former value.

The guidelines states only the main living spaces need to be assessed. Bedrooms do not need to be assessed. The windows identified in the preliminary assessment and indicated in Figures 6-12 that face within 90° of due South are assessed and the results are set out in Table 9.

Annual Probable Sunlight HoursAPSH >25% Target Sept 21 - Mar 21 PSH >5% Target Meets criteria of

>25% APSH and >5% PSH Or

<25% or <5% PSH but >80% Existing Value

Location ID

Assumed room use

Existing Proposed Ratio Existing Proposed Ratio

% of APSH

% of APSH

If less than 25% APSH Target >80%

% PSH % PSH If less than 5% PSH Target >80%

68 Churchfields

1 Living room 71.0% 64.8% 91.3% 29.5% 26.1% 88.4% Yes

2 Family room 71.0% 59.9% 84.4% 29.3% 24.0% 81.9% Yes

3 Family room 46.3% 24.9% 53.7% 15.4% 9.3% 60.5% Yes

67 Churchfields

13 Kitchen 70.4% 61.3% 87.2% 23.6% 17.5% 74.3% Yes

14 Study 52.4% 52.4% 100.0% 10.7% 10.7% 100.0% Yes

44 Churchfields

24 Living room 75.7% 69.5% 91.8% 26.6% 21.6% 81.0% Yes

25 Family room 60.2% 52.5% 87.3% 23.5% 17.5% 74.6% Yes

26 Family room 36.1% 31.7% 87.8% 10.9% 7.2% 66.4% Yes

30 Churchfields

29 Living room 58.6% 53.9% 91.9% 14.4% 10.4% 72.7% Yes

30 Kitchen 60.2% 52.5% 87.2% 18.4% 11.9% 65.0% Yes

29 Churchfields

33 Kitchen 64.2% 55.9% 87.0% 18.4% 11.5% 62.4% Yes

34 Dining 50.2% 40.7% 81.0% 16.6% 8.7% 52.3% Yes

28 Churchfields

37 Living room 49.1% 44.1% 89.9% 9.8% 5.7% 57.8% Yes

38 Kitchen 53.2% 42.1% 79.2% 17.4% 8.2% 47.1% Yes

27 Churchfields

41 Kitchen 67.8% 56.3% 83.0% 21.3% 11.7% 55.0% Yes

42 Dining 42.9% 35.2% 82.1% 12.9% 6.5% 50.5% Yes

26 Churchfields

45 Dining 40.2% 33.2% 82.6% 12.4% 6.6% 53.1% Yes

46 Kitchen 68.4% 57.7% 84.4% 21.4% 12.5% 58.6% Yes

25 Churchfields

49 Kitchen 69.0% 57.5% 83.2% 21.9% 12.2% 56.0% Yes

50 Dining 51.6% 42.8% 82.9% 16.9% 9.5% 56.5% Yes

24 Churchfields

53 Dining 54.7% 45.4% 83.0% 16.3% 8.5% 52.6% Yes

54 Kitchen 63.6% 53.4% 83.9% 17.3% 8.8% 50.7% Yes

23 Churchfields

57 Kitchen 62.9% 53.0% 84.2% 17.5% 9.2% 52.8% Yes

58 Dining 44.2% 37.1% 83.8% 13.2% 7.3% 55.2% Yes

22 Churchfields

61 Dining 46.2% 38.9% 84.2% 11.8% 5.7% 48.4% Yes

DRAFT

18

Annual Probable Sunlight HoursAPSH >25% Target Sept 21 - Mar 21 PSH >5% Target Meets criteria of

>25% APSH and >5% PSH Or

<25% or <5% PSH but >80% Existing Value

Location ID

Assumed room use

Existing Proposed Ratio Existing Proposed Ratio

% of APSH

% of APSH

If less than 25% APSH Target >80%

% PSH % PSH If less than 5% PSH Target >80%

62 Kitchen 62.3% 52.6% 84.5% 16.1% 8.1% 50.3% Yes

21 Churchfields

65 Kitchen 60.9% 53.2% 87.3% 15.8% 9.4% 59.4% Yes

66 Dining 47.4% 43.1% 90.8% 13.5% 9.8% 73.0% Yes

20 Churchfields

69 Dining 41.3% 37.5% 90.7% 9.8% 6.6% 67.4% Yes

70 Kitchen 61.1% 56.4% 92.3% 15.1% 11.2% 74.0% Yes

19 Churchfields

73 Kitchen 60.5% 57.5% 95.2% 15.4% 13.0% 84.2% Yes

74 Dining 30.4% 29.8% 97.8% 6.9% 6.3% 92.0% Yes

18 Churchfields

77 Dining 28.0% 27.8% 99.3% 7.4% 7.2% 97.7% Yes

78 Kitchen 61.0% 58.3% 95.5% 15.0% 12.8% 85.0% Yes

17 Churchfields

81 Kitchen 61.1% 59.9% 98.0% 16.0% 14.9% 93.6% Yes

82 Dining 38.4% 38.2% 99.5% 10.2% 10.0% 98.3% Yes

16 Churchfields

85 Living room 35.5% 35.1% 98.9% 9.3% 8.9% 96.5% Yes

86 Living room 56.9% 55.7% 97.9% 12.6% 11.6% 92.0% Yes

87 Living room 48.2% 47.5% 98.5% 12.2% 11.6% 95.0% Yes

88 Kitchen 46.3% 45.4% 98.0% 10.5% 9.7% 92.8% Yes

15 Churchfields

91 Kitchen 49.9% 51.3% 102.8% 14.7% 15.9% 107.9% Yes

92 Dining 51.4% 50.5% 98.3% 11.5% 10.8% 93.6% Yes

14 Churchfields

95 Kitchen 40.6% 41.3% 101.6% 7.7% 8.3% 107.1% Yes

Table 9: Annual Probable Sunlight hours to adjoining properties

5.2 DiscussionNo.s 14 to 30, 44, 67 & 68 Churchfields are the relevant houses which have a living space with a window facing within 90° of due South. These were assessed and all windows have an APSH percentage greater than the recommended 25% (414 hours) and 5% (75 hours) from 21 September to 21 March.

In assessing the overall quality of light within a space it is important to note that sunlight is of lesser importance than good quality daylight. Direct sunlight is intermittent and a bright well lit living space is more desirable than a gloomy living space with spells of sunshine.

5.3 ConclusionAll windows assessed exceed the target values set out for annual and winter probable sunlight hours. The proposed development meets the recommendations of the BRE guidelines and any potential loss of sunlight will be negligible.

DRAFT

19

6: Daylight to Proposed Development.The BRE guidelines recommend that the Average Daylight Factor (ADF) be assessed in habitable rooms of new developments. BS 8206-2 gives minimum values of ADF of 2% for kitchens and living rooms which include a kitchen, 1.5% for living rooms and 1% for bedrooms. An average daylight factor of 5% is a well ‘daylit’ space. Where there are two room uses within a space then the higher ADF value should be used.

The factors that affect ADF are room depth, aspect, window size relative to floor area and closeness to an adjacent obstruction. All habitable rooms on the ground, first and the fourth floors were assessed. Results are shown for each block in table form together with false colour plans from generated analysis.

A01.01

A01.02

A02.02

A02.01

A02.03

A03.02

A03.01

A04.01

A04.02

A05.01

A05.02

A06.03

A06.02

A06.01

A07.01

A07.02

A08.01

A08.02

A09.02

A09.01

A10.02

A00.01

A10.01

Figure 14: Villa A False Colour Plan of ground & first floors indicating habitable rooms assessed for ADF

A11.01

A11.02

A12.02

A12.01

A12.03

A13.02

A13.01

A14.01

A14.02

A15.01

A15.02

A16.03

A16.02

A16.01

A17.01

A17.02

A18.01

A18.02

A19.02

A19.01

A20.03

A20.01

A15.03

A20.02

A17.03

Gro

und

Floo

rFi

rst F

loor

ADF

7%

0%

DRAFT

20

Average Daylight Factor - Villa ASpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment

Ground Floor

A00.01 Concierge 85.9 207 8.82% N/A Meets Criteria

A01.01 Liv / Kit 24.1 66 2.40% 2 Meets Criteria

A01.02 Bed 10.0 30 3.48% 1 Meets Criteria





















First Floor


























Table 10: Villa A - Average Daylight Factor of Ground & First Floor Habitable Rooms

DRAFT

21

Figure 15: Villa B False Colour Plan of ground, first and fourth floors indicating habitable rooms assessed for ADF

ADF

7%

0%

B01.01

B01.02

B02.02

B03.02

B03.01

B04.01

B04.02

B05.03

B05.01

B06.02

B06.01

B07.01

B07.02

B08.02

B08.01

B01.03

B02.01

B03.03

B04.03

B05.02

B08.03

B09.01

B09.02

B10.02

B11.02

B11.01

B12.01

B12.02

B13.03

B13.01

B14.02

B14.01

B15.01

B15.02

B16.02

B16.01

B09.03

B10.01

B11.03

B12.03

B13.02

B16.03

Gro

und

Floo

r

B33.01

B34.02

B34.01

B35.03

B35.01

B36.02

B36.01

B37.01

B37.02

B33.02

B34.03

B35.02

B33.03

Four

th F

loor

Firs

t Flo

or

DRAFT

22

Average Daylight Factor - Villa BSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment

Ground Floor

B01.01 Liv / Kit 28.3 81 5.80% 2 Meets Criteria

B01.02 Bed 11.7 28 4.70% 1 Meets Criteria




















First Floor






















Fourth Floor






DRAFT

23

Average Daylight Factor - Villa BSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment









Table 11: Villa B - Average Daylight Factor of Ground, First & Fourth Floor Habitable Rooms

DRAFT

24

Figure 16: Villa C False Colour Plan of ground, first and fourth floors indicating habitable rooms assessed for ADF

C01.01

C01.02

C02.01

C03.01

C03.02

C04.01

C04.02

C05.03

C05.01

C06.03

C06.01

C06.02

C07.02

C07.01

C01.03

C02.02

C04.03

C05.02

C07.03

C08.01

C08.02

C09.01

C10.01

C10.02

C11.01

C11.02

C12.03

C12.01

C13.03

C13.01

C13.02

C14.02

C14.01

C08.03

C09.02

C11.03

C12.02

C14.03

C29.01

C29.02

C30.01

C31.01

C31.02

C32.01

C32.02

C33.03

C33.01

C34.03

C34.01

C34.02

C35.02

C35.01

C29.03

C30.02

C32.03

C33.02

C35.03

Gro

und

Floo

rFi

rst F

loor

ADF

7%

0%

Four

th F

loor

DRAFT

25

Average Daylight Factor - Villa CSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment

Ground Floor

C01.01 Liv / Kit 28.3 81 5.73% 2 Meets Criteria

C01.02 Bed 11.7 28 2.01% 1 Meets Criteria


















First Floor




















Fourth Floor












DRAFT

26

Average Daylight Factor - Villa CSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment









Table 12: Villa C - Average Daylight Factor of Ground & First Floor Habitable Rooms

D47.01

D47.02

D48.02

D51.03

D51.01

D53.01

D53.02

D54.02

D54.01

D47.03

D48.01

D51.02

D50.01

D50.02

D52.01

D52.02

D49.01

D49.02

D55.03

D55.01

D55.02

D00.04

Figure 17: Villa D False Colour Plan of 4th floor indicating habitable rooms assessed for ADF

Four

th F

loor

ADF

7%

0%

DRAFT

27

Figure 18: Villa D False Colour Plan of ground & 1st floors indicating habitable rooms assessed for ADF

D11.01

D11.02

D12.01

D14.01

D14.02

D15.01

D18.03

D18.01

D20.01

D20.02

D21.02

D21.01

D11.03

D12.02

D15.02

D18.02

D15.03

D16.01

D16.02

D17.01

D17.02

D17.02

D19.01

D19.02

D13.01

D13.02

D22.03

D22.01

D22.02

Firs

t Flo

or

D01.01

D01.02

D02.01

D03.01

D03.02

D04.01

D07.03

D07.01

D09.01

D09.02

D10.02

D10.01

D01.03

D02.02

D04.02

D07.02

D00.01

D04.03

D05.01

D05.02

D06.01

D06.02

D06.02

D10.03

D08.01

D08.02

Gro

und

Floo

r

ADF

7%

0%

DRAFT

28

Average Daylight Factor - Villa DSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment

Ground Floor

D00.01 Gym 66.3 174 10.45% N/A Meets Criteria

D01.01 Liv / Kit 29.1 69 5.64% 2 Meets Criteria

D01.02 Bed 13.1 36 3.77% 1 Meets Criteria

























First Floor























DRAFT

29

Average Daylight Factor - Villa DSpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment








Fourth Floor

D04.00 Co working 105.5 280 17.14% N/A Meets Criteria






















Table 13: Villa D - Average Daylight Factor of Ground, First & Fourth Floor Habitable Rooms

DRAFT

30

E01.01

E01.02

E02.01E02.02

E03.02 E03.01E04.01E05.01E05.02

E00.01

E02.03

E03.03

E04.02E06.01 E06.02

E06.03

E07.01

E07.02

E08.01E08.02

E09.02 E09.01E10.01E11.01E11.02

E08.03

E09.03

E10.02E12.01 E12.02

E12.03

E13.03E13.01

E13.02

E28.01E29.01E29.02 E28.02E30.01 E30.02

E30.03

E31.03E31.01

E31.02

Gro

und

Floo

rFi

rst F

loor

Four

th F

loor

Figure 19: Villa E False Colour Plan of ground, first and fourth floors indicating habitable rooms assessed for ADF

DRAFT

31

Average Daylight Factor - Villa ESpace ID Description Area m2 Sensor Count ADF Minimum ADF Comment

Ground Floor

E00.01 Cafe 69.8 176 9.42% N/A Meets Criteria

E01.01 Liv / Kit 20.1 55 6.93% 2 Meets Criteria

E01.02 Bed 11.5 35 4.95% 1 Meets Criteria














First Floor



















Fourth Floor











Table 14: Villa E - Average Daylight Factor of Ground, First & Fourth Floor Habitable Rooms

DRAFT

32

6.1 DiscussionWithin the development the design was optimised for good quality daylight. Priority is given to main living spaces over bedrooms and where possible they are positioned away from inner corners or projecting stair cores to maximise available daylight. The use of very large windows also enhances available daylight and light penetration to the depths of the rooms.

The higher target value of 2% is selected for all the main living rooms because they contain a kitchen and the BRE guide and BS 8602:2 recommend that the higher value should be used were there are multiple uses in a room. The assessment plane covers 100% of living space being considered and in some cases excludes the circulation space from the apartment entrance to the main living space. The corridors associated with the living space would be traditionally be internalised and are deep within the plan where natural light levels will not penetrate and artificial lighting will be required. The assessment plane in these rooms still exceed 80% of the floor plate.

All habitable rooms on the ground, first and fourth floors were assessed. Its is evident from the results that the ADF values improve with the higher the floor level. This is due to increased access to the sky with less obstruction from opposing buildings. All the rooms assessed exceed the minimum ADF levels with a large number of the rooms exceeding an ADF of 5%, this is particularly evident in the rooms with dual aspect.

6.2 ConclusionAll the rooms assessed exceed the minimum recommendations for the Average Daylight Factor and will be well daylit. The proposed development meets the recommendations of the BRE Guidelines and BS8206 Part 2:2008 Lighting for Buildings, Code of Practice for Daylighting.

DRAFT

33

The BRE document indicates that for an amenity area, such as a garden, to have good quality sunlight throughout the year, 50% should receive in excess of 2 hours sunlight on the 21st March. It also states that front gardens need not be assessed for sunlight.

The guidelines states that the 21 March should be used for the assessment and that “Sunlight at an altitude of 10° or less does not count, because it is likely to be blocked by low level planting anyway.” The amenity space is assessed for the amount of direct sunlight received by the space in 5 minute intervals between 8am and 6pm on the 21st March over an analysis grid with a 300mm grid size and the average is calculated.

7.1 Private amenity space to neighbouring properties.No.s 14 - 30 Churchfields are to the North of the Proposed Development, No.s 67 & 68 are to the East. The private amenity space to the neighbouring properties which is generally the rear garden were assessed for the availability of sunlight on the ground. The existing and proposed radiation maps are in Figures 20 - 22, the results can be seen in Table 15 below.

Sunlight on the Ground - Adjacent ResidencesLocation ID Location Existing Proposed Ratio Meets criteria of

>50% area Or if <50% but >80% Existing Value

% Area receiving 2 hours sunlight on 21st March

L1 Churchfields 14 83.8 83.8 100.0% Meets criteria

L2 Churchfields 15 79.7 79.7 100% Meets criteria

L3 Churchfields 16 71.0 76.7 108% Meets criteria

L4 Churchfields 17 56 74.5 133% Meets criteria

L5 Churchfields 18 54.3 73 134% Meets criteria

L6 Churchfields 19 54.8 70 127.7% Meets criteria














Table 15: Calculation of Sun on the Ground to Adjacent Amenity Spaces.

7.2 DiscussionThe adjacent residential properties which have private amenity spaces (rear gardens) facing toward the proposed development are all in Churchfields. There is a marginal reduction to the percentage of the amenity spaces receiving at least 2 hours sunlight to some of the gardens but this is not reduced to 80% of their former value set out in the BRE guidelines. There is a positive impact to some of the gardens from 15 to 21 Churchfields where the removal of the boundary structures will allow increased availability of access to the sun.

The CUS grounds are entirely to the south of the proposed buildings and will not have any reduction in sunlight to the amenity space.

7.3 ConclusionA small number of gardens will have a small reduction to the percentage of the amenity spaces receiving at least 2 hours sunlight on the 21st March but none are reduced below 80% of their existing value. Additionally some amenity spaces will experience an increased availability. The proposed development meets the recommendations of the BRE guidelines.

7: Sunlight to gardens and open spaces

DRAFT

34

Figure 20: No.s 15 - 30 Churchfields: Existing radiation map generated through the calculation of sun on the ground, on the 21st March. Scale indicates 0-8 hours of sunlight.

Figure 21: No.s 15 - 30 Churchfields: Proposed radiation map generated through the calculation of sun on the ground, on the 21st March. Scale indicates 0-8 hours of sunlight.

N

N Existing

Proposed

30

28

29

272625

Churchfields

44

67

68

2423222120191817

161514

30

28

29

272625

Churchfields

44

67

68

2423222120191817

161514

DRAFT

35

N

Figure 22: No.s 67 & 68 Churchfields: Existing & Proposed radiation maps generated through the calculation of sun on the ground, on the 21st March. Scale indicates 0-8 hours of sunlight.

No. 67 No. 67

No. 68 No. 68

Existing Proposed

DRAFT

36

S2

7.4 Sunlight to amenity within the proposed development

The areas of amenity within this proposal have been assessed with a calculation of Sun on the Ground on the 21st March. A location plan is shown in Figure 23, generated analysis in Figure 24 and the results are set out in Table 16 below.

Sunlight on the ground - within developmentLocation ID Location Proposed Meets criteria if

>50% area receiving 2 hours sunlight on 21st March% Area receiving 2 hours sunlight on 21st March

S1 Ground level 88.4% Meets criteria

S2 Roof terrace, Villa D 92% Meets criteria

Table 16: Calculation of Sun on the Ground to amenity area within the proposed development.

Figure 23: Landscape plan, locating areas of amenity assessed for direct sunlight.

N

S1

DRAFT

37

S1

S2

Figure 24: Proposed Radiation map of amenity areas, showing available sunlight on 21st March. The scale represents the percentage of daylight received from 0 - 8 hours.

N

7.5 ConclusionA variety of amenity spaces have been designed into this scheme, they are well oriented for sunlight and over 88% of the proposed amenity spaces will have over 2 hours sunlight on the 21st March. The proposed development meets the recommendations of the BRE guidelines.

DRAFT

38

8: Shadow Diagrams

8.1 BRE Guidance on Shadow StudiesThe BRE guidelines recommend using the 21st March for plotting shadow, it states: “If a space is used all year round, the equinox (21 March) is the best date for which to prepare shadow plots as it gives an average level of shadowing. Lengths of shadows at the autumn equinox (21 September) will be the same as those for 21 March, so a separate set of plots for September is not required.”

June 21st and December 21st are provided below for information but it should be noted that the summer solstice is the best case scenario with shadows at their shortest. In Winter even low buildings will cast long shadows and it is common for large areas of the ground to be in shadow throughout the day especially in a built up area and sun barely rises above an altitude of 10° during the course of the day. The guidelines recommends that Sunlight at an altitude of 10° or less does not count. Below are the times for the Equinox and Solstice that the sun is above 10° altitude rounded to the nearest half hour.

Equinox: between 8:30 and 17:30Summer Solstice: Between 6:30 and 20:00Winter Solstice: Between 10:30 and 14:00

Section 8.3 shows the proposed shadow diagrams for the Equinox on the 21st March at 2 hourly intervals during the day between 09:00 and 17:00. Section 8.4 shows the proposed shadow diagrams for the Summer Solstice on the 21st June at 2 hourly intervals during the day between 10:00 and 18:00. Section 8.5 shows the proposed shadow diagrams for the Equinox on the 21st September at 2 hourly intervals during the day between 09:00 and 17:00. Section 8.6 shows the proposed shadow diagrams for the Winter Solstice on the 21st December at 2 hourly intervals during the day between 10:00 and 16:00.

The shadows cast on the September equinox are the same as the March Equinox. They are included here with the Daylight Saving Time (DST) applied, as with the Summer Solstice diagrams. Much of the site is a greenfield, where there is no shadows cast from any structures on the site at present.

The use of shadow diagrams as an assessment method should be taken over the course of the day and not a specific time due to the transient nature of the sun and the shade caused by obstructions.

In relation to the effects of trees and hedges the BRE guidelines states, “It is generally more difficult to calculate the effects of trees on daylight because of their irregular shape and because some light will generally penetrate through the crown. Where the effects of a new building on existing buildings nearby is being analysed, it is usual to ignore the effects of existing trees. This is because daylight is at its scarcest and most valuable in winter when most trees will not be in leaf.”

The trees were not included because they are mostly deciduous and guidelines recommends only including trees where there are dense bands of evergreen trees.

8.2 ConclusionShadow diagrams are a visual aid to understand where possible shading may occur. The BRE guidelines recommends using the March Equinox due the equal length of the day and night time.

It can be seen that the proposed development does not cast any additional shading to the surrounding properties on the 21st March until late evening when the sun is low and the existing walls cast long shadows and are self shading. There will be no shading to the CUS grounds which lie entirely to the south of the proposed development.

DRAFT

39

Proposed

Existing

N

N

8.3 Shadow Casting diagrams March Equinox

Figure 25: Shadow diagrams 21 March 09:00 GMT

DRAFT

40

Proposed

Existing

N

N


DRAFT

41


Proposed

Existing

N

N

DRAFT

42


Proposed

Existing

N

N

DRAFT

43


Proposed

Existing

N

N

DRAFT

44

Figure 30: Shadow diagrams 21 June 10:00 GMT +1 (DST)

8.4 Shadow Casting diagrams June Solstice

Proposed

Existing

N

N

DRAFT

45


Proposed

Existing

N

N

DRAFT

46


Proposed

Existing

N

N

DRAFT

47


Proposed

Existing

N

N

DRAFT

48


Proposed

Existing

N

N

DRAFT

49

N

8.5 Shadow Casting diagrams September Equinox

Figure 35: Shadow diagrams 21 September 09:00 GMT +1 (DST)

N

Proposed

Existing

DRAFT

50

N

N


Proposed

Existing

DRAFT

51


Proposed

Existing

N

N

DRAFT

52


Proposed

Existing

N

N

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53


Proposed

Existing

N

N

DRAFT

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Figure 40: Shadow diagrams 21 December 10:00 GMT

8.6 Shadow Casting diagrams December Solstice

Proposed

Existing

N

N

DRAFT

55


Proposed

Existing

N

N

DRAFT

56


Proposed

Existing

N

N

DRAFT

57


Proposed

Existing

N

N

Daylight & Sunlight Assessments of a Strategic Housing ...

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