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Hea 01 Visual comfort

Number of credits available	Minimum standards
Building type dependent	No

Aim

To ensure daylighting, artificial lighting and occupant controls are considered at the design stage to ensure best practice in visual performance and comfort for building occupants.

Assessment criteria

This issue is split into four parts:

Glare control (1 credit)
Daylighting (up to 2 credits - building type dependent)
View out (1 credit except for a Healthcare building with inpatient areas, which has 2 credits available)
Internal and external lighting (1 credit)

The following is required to demonstrate compliance:

One credit - Glare control

The potential for disabling glare has been designed out of all relevant building areas using a glare control strategy, either through building form and layout and/or building design measures (see compliance note CN3).
The glare control strategy avoids increasing lighting energy consumption, by ensuring that:
1. The glare control system is designed to maximise daylight levels under all conditions while avoiding disabling glare in the workplace or other sensitive areas. The system should not inhibit daylight from entering the space under cloudy conditions, or when sunlight is not on the façade.
AND
1. The use or location of shading does not conflict with the operation of lighting control systems.

Up to two credits - Daylighting (building type dependent)

Daylighting criteria have been met using either of the following options:
1. The relevant building areas meet good practice daylight factor(s) and other criterion as outlined in Table 10 and Table 11 .
OR
1. The relevant building areas meet good practice average and minimum point daylight illuminance criteria as outlined in Table 12 .

Table 10 Minimum values of average daylight factor required

Building/area type	Credits	Average daylight factor required	Minimum area (m²) to comply	Other requirements
Education buildings
Pre-schools, schools, further education- occupied spaces	2	2%	80%	EITHER (a) OR {(b) and (c)} in Table 11
Higher education- occupied spaces	1	2%	60%
Higher education- occupied spaces	2	2%	80%
Healthcare buildings
Staff and public areas	2	2%	80%	EITHER (a) OR {(b) and (c)} in Table 11
Occupied patient’s areas (dayrooms, wards) and consulting rooms	2	3%	80%	EITHER (a) OR {(b) and (c)} in Table 11
Multi-residential buildings
Kitchen	1	2%	80%	EITHER (a) OR (c) in Table 11
Living rooms, dining rooms, studies (including home office)		2 %	80%
Non-residential or communal occupied spaces		2%	80%
Retail buildings
Sales areas	1	-	35%	Point daylight factors of 2% or more
Other occupied areas	1	2%	80%	EITHER (a) OR {(b) and (c)} in Table 11
Courts, Industrial, Office, Prison buildings and all Other building types
Cells and custody cells	1	1.5%	80%	N/A
Internal association or atrium area		3%	80%	EITHER a uniformity ratio of at least 0.7 OR a minimum point daylight factor of 2.1%
Patient care spaces		3%	80%	EITHER (a) OR {(b) and (c)} in Table 11
Teaching, lecture and seminar spaces		2%	80%	EITHER (a) OR {(b) and (c)} in Table 11
All occupied spaces, unless indicated in Hea 01 Visual comfort		2%	80%	EITHER (a) OR {(b) and (c)} in Table 11

Table 11 Daylighting uniformity criteria

Ref	Criteria
(a)	A uniformity ratio of at least 0.3 or a minimum point daylight factor of at least 0.3 times the relevant average daylight factor value in Table 10 . Spaces with glazed roofs, such as atria, must achieve a uniformity ratio of at least 0.7 or a minimum point daylight factor of at least 0.7 times the relevant average daylight factor value in Table 10 .
(b)	At least 80% of the room has a view of sky from desk or table top height (0.85m in multi-residential buildings, 0.7m in other buildings).
(c)	The room depth criterion d/w +d/HW < 2/(1-RB) is satisfied. Where: d = room depth, w = room width, HW = window head height from floor level, RB = average reflectance of surfaces in the rear half of the room, Note: Table 17 gives maximum room depths in metres for different room widths and window head heights of side-lit rooms

Ref

Criteria

(a)

A uniformity ratio of at least 0.3 or a minimum point daylight factor of at least 0.3 times the relevant average daylight factor value in Table 10 . Spaces with glazed roofs, such as atria, must achieve a uniformity ratio of at least 0.7 or a minimum point daylight factor of at least 0.7 times the relevant average daylight factor value in Table 10 .

(b)

At least 80% of the room has a view of sky from desk or table top height (0.85m in multi-residential buildings, 0.7m in other buildings).

(c)

The room depth criterion d/w +d/HW < 2/(1-RB) is satisfied.

Where:

d = room depth,

w = room width,

HW = window head height from floor level,

RB = average reflectance of surfaces in the rear half of the room,

Note:

Table 17 gives maximum room depths in metres for different room widths and window head heights of side-lit rooms

Table 12 Space type and illuminance requirements - both criteria (average illuminance and minimum point illuminance) should be met.

Area type	Credits	Minimum area to comply	Average daylight illuminance (averaged over entire space)	Minimum daylight illuminance at worst lit point
Education buildings
Pre-schools, schools, further education - occupied spaces	2	80%	At least 300 lux for 2000 hours per year or more	At least 90 lux for 2000 hours per year or more
Higher education - occupied spaces	1	60%
OR Higher education - occupied spaces	2	80%
Healthcare buildings
Staff and public areas	2	80%	At least 300 lux for 2000 hours per year or more	At least 90 lux for 2000 hours per year or more
Occupied patient's areas (dayrooms, wards) and consulting rooms	2	80%	At least 300 lux for 2650 hours per year or more	At least 90 lux for 2650 hours per year or more
Multi-residential buildings
Kitchen	1	100%	At least 100 lux for 3450 hours per year or more	At least 30 lux for 3450 hours per year or more
Living rooms, dining rooms, studies (including home office)		100%	At least 100 lux for 3450 hours per year or more	At least 30 lux for 3450 hours per year or more
Non-residential/communal occupied spaces		80%	At least 200 lux for 2650 hours per year or more	At least 60 lux for 2650 hours per year or more
Retail buildings
Sales areas	1	35%	At least 200 lux point daylight illuminances for 2650 hours per year or more
Other occupied areas	1	80%	At least 200 lux for 2650 hours per year or more	At least 60 lux for 2650 hours per year or more
Courts, Industrial, Office, Prison buildings and all Other building types
Cells and custody cells	1	80%	At least 100 lux for 3150 hours per year or more	N/A
Internal association or atrium		80%	At least 300 lux for 2650 hours per year or more	At least 210 lux for 2650 hours per year
Patient care spaces		80%	At least 300 lux for 2650 hours per year or more	At least 210 lux for 2650 hours per year or more
Teaching, lecture and seminar spaces		80%	At least 300 lux for 2000 hours per year or more	At least 90 lux for 2000 hours per year or more
All occupied spaces, unless indicated in Relevant definitions		80%	At least 300 lux for 2000 hours per year or more	At least 90 lux for 2000 hours per year or more

One credit - View out

95% of the floor area in each relevant building areas is within 7m of a wall which has a window or permanent opening that provides an adequate view out.
The window/opening must be ≥ 20% of the surrounding wall area (refer to Hea 01 Visual comfort in the Additional information section). Where the room depth is greater than 7m, compliance is only possible where the percentage of window/opening is the same as, or greater than, the values in table 1.0 of BS 82061BS 8206-2:2008 Lighting for buildings Code of practice for daylighting.
In addition, the building type criteria in Table 13 are applicable to view out criteria.

Table 13 View out building specific requirements.

Building type	View out requirements
Prison buildings	Cells An adequate view out from a normal standing or sitting position and the distance between each window and nearest external solid object (i.e. buildings, screens, walls/fences) is ≥ 10m. Where existing features prevent compliance with this criteria in less than 20% of the cells within the building, the credit can still be awarded. Patient occupied spaces See Healthcare requirements for these spaces.
Multi-residential buildings	Self-contained flats - living rooms Sheltered housing - communal lounges, individual bedrooms and bedsits All positions within relevant areas are to be within 5m of a wall which has a window or permanent opening providing an adequate view out. The window/opening must be ≥ 20% of the surrounding wall area.
Healthcare buildings with inpatient areas (one additional credit)	Patient occupied spaces, e.g. wards and dayrooms As criteria 4 and 5 for the relevant building areas PLUS the distance between the wall with the window/opening and nearest external solid object (e.g. buildings, screens, walls/fences) is ≥ 10m.

Building type

View out requirements

Prison buildings

Cells

An adequate view out from a normal standing or sitting position and the distance between each window and nearest external solid object (i.e. buildings, screens, walls/fences) is ≥ 10m.

Where existing features prevent compliance with this criteria in less than 20% of the cells within the building, the credit can still be awarded.

Patient occupied spaces

See Healthcare requirements for these spaces.

Multi-residential buildings

Self-contained flats - living rooms

Sheltered housing - communal lounges, individual bedrooms and bedsits

All positions within relevant areas are to be within 5m of a wall which has a window or permanent opening providing an adequate view out. The window/opening must be ≥ 20% of the surrounding wall area.

Healthcare buildings with inpatient areas (one additional credit)

Patient occupied spaces, e.g. wards and dayrooms

As criteria 4 and 5 for the relevant building areas PLUS the distance between the wall with the window/opening and nearest external solid object (e.g. buildings, screens, walls/fences) is ≥ 10m.

One credit - Internal and external lighting levels, zoning and control

Internal lighting

All fluorescent and compact fluorescent lamps are fitted with high frequency ballasts.
Internal lighting in all relevant areas of the building is designed to provide an illuminance (lux) level appropriate to the tasks undertaken, accounting for building user concentration and comfort levels. This can be demonstrated through a lighting design strategy that provides illuminance levels in accordance with the SLL Code for Lighting 2012 and any other relevant industry standard.
For areas where computer screens are regularly used, the lighting design complies with CIBSE Lighting Guide 72CIBSE Lighting Guide 7, 2015 sections 2.4, 2.20, and 6.10 to 6.20. This gives recommendations highlighting:
1. Limits to the luminance of the luminaires to avoid screen reflections. (Manufacturers’ data for the luminaires should be sought to confirm this.)
2. For uplighting, the recommendations refer to the luminance of the lit ceiling rather than the luminaire; a design team calculation is usually required to demonstrate this.
3. Recommendations for direct lighting, ceiling illuminance, and average wall illuminance.

External lighting

All external lighting located within the construction zone is designed to provide illuminance levels that enable users to perform outdoor visual tasks efficiently and accurately, especially during the night. To demonstrate this, external lighting provided is specified in accordance with BS 5489-1:2013 Lighting of roads and public amenity areas3BS 5489-1:2013 Lighting of roads and public amenity areas, Code of Practice for the design of road lighting, BSI, 2013 and BS EN 12464-2:2014 Light and lighting - Lighting of work places - Part 2: Outdoor work places.

Zoning and occupant control

Internal lighting is zoned to allow for occupant control (see Relevant definitions) in accordance with the criteria below for relevant areas present within the building:
1. In office areas, zones of no more than four workplaces
2. Workstations adjacent to windows/atria and other building areas separately zoned and controlled
3. Seminar and lecture rooms: zoned for presentation and audience areas
4. Library spaces: separate zoning of stacks, reading and counter areas
5. Teaching space or demonstration area
6. Whiteboard or display screen
7. Auditoria: zoning of seating areas, circulation space and lectern area
8. Dining, restaurant, café areas: separate zoning of servery and seating/dining areas
9. Retail: separate zoning of display and counter areas
10. Bar areas: separate zoning of bar and seating areas
11. Wards or bedded areas: zoned lighting control for individual bed spaces and control for staff over groups of bed spaces
12. Treatment areas, dayrooms, waiting areas: zoning of seating and activity areas and circulation space with controls accessible to staff.
Note: the criteria for zoning of lighting control are excluded for assessments of prison buildings.
Areas used for teaching, seminar or lecture purposes have lighting controls provided in accordance with CIBSE Lighting Guide 54SLL LIGHTING GUIDE 5: Lecture, teaching and conference rooms, 1991
In addition the building type criteria in Table 14 (where relevant);

Table 14 Internal and external lighting building specific requirements.

Building type	Internal and external lighting requirements
Education buildings	Manual lighting controls are easily accessible for the teacher while teaching and on entering/leaving the teaching space.
Prison buildings	Cells Lit to a maintained illuminance of 200 lux at table top level. In addition there must be the facility (using, for example, dimming, step switching or separate task and general lighting) for the occupant of the cell to select a lower level of general lighting if required. Exercise yards Lit to a maintained illuminance of at least 10 lux. However, if such spaces are, or will be, used as sports facilities they must be lit to a maintained illuminance of 100 lux.
Court buildings	Separate zoning is also provided for the following areas (as a minimum): Judge’s/magistrate’s bench Dock Jury area Public seating area. Lighting control of the zones in the above spaces, and the courtroom as a whole, cater for the following settings: Full lighting (to allow cleaning etc.) Normal lighting (for court sessions) Dimmed (for the purpose of showing audio-visual evidence, but allowing enough light for note taking).

Building type

Internal and external lighting requirements

Education buildings

Manual lighting controls are easily accessible for the teacher while teaching and on entering/leaving the teaching space.

Prison buildings

Cells

Lit to a maintained illuminance of 200 lux at table top level. In addition there must be the facility (using, for example, dimming, step switching or separate task and general lighting) for the occupant of the cell to select a lower level of general lighting if required.

Exercise yards

Lit to a maintained illuminance of at least 10 lux. However, if such spaces are, or will be, used as sports facilities they must be lit to a maintained illuminance of 100 lux.

Court buildings

Separate zoning is also provided for the following areas (as a minimum):

Judge’s/magistrate’s bench
Dock
Jury area
Public seating area.

Lighting control of the zones in the above spaces, and the courtroom as a whole, cater for the following settings:

Full lighting (to allow cleaning etc.)
Normal lighting (for court sessions)
Dimmed (for the purpose of showing audio-visual evidence, but allowing enough light for note taking).

Exemplary level criteria

The following outlines the exemplary level criteria to achieve an innovation credit for daylighting:

Daylighting criteria have been met using either of the following options:
1. Relevant building areas meet exemplary daylight factor(s) and the relevant criteria in Table 15 .
OR
1. Relevant building areas meet exemplary average and minimum point daylight illuminance criteria in Table 16 .

Table 15 Exemplary level values of average daylight factor required.

Area type	Credits	Average daylight factor required	Minimum area (m2) to comply	Other requirements
All building types	The criteria outlined in Table 10 and Table 11 concerning uniformity ratio (a), view of sky (b) or room depth criterion (c) are met where they are used to demonstrate compliance.
All building types (excluding retail – see below)
Functions as identified in the standard criteria (multi storey buildings)	1	3%	80%	Where used, a minimum point daylight factor of 1.2% OR 2.1% for spaces with glazed roofs, such as atria
Functions as identified in the standard criteria (single storey buildings)		4%	80%	Where used, a minimum point daylight factor of 1.6% OR 2.8% for spaces with glazed roofs, such as atria
Prisons and court cells		2%	80%	N/A
Prison internal association/atrium area		5%	80%	A uniformity ratio of at least 0.7 or a minimum point daylight factor of 3.5%
Retail
Sales areas	1	N/A	50%	A minimum point daylight factor of 2% must be achieved in the compliant areas. Assess total sales areas without rounding up to the nearest room.
Common areas and offices (multi storey buildings)		3%	80%	Where used, a minimum point daylight factor of 1.2% OR 2.1% for spaces with glazed roofs, such as atria
Common areas and offices (single storey buildings)		4%	80%	Where used, a minimum point daylight factor of 1.6% OR 2.8% for spaces with glazed roofs, such as atria

Table 16 Exemplary level illuminance value requirements. Both criteria (average illuminance and minimum point illuminance) should be met.

Area type	Credits	Minimum area to comply	Average daylight illuminance (averaged over entire space)	Minimum daylight illuminance at worst lit point
All building types (excluding retail – see below)
Multi-storey buildings Occupied spaces (unless indicated below)	1	80%	At least 300 lux for 2650 hours per year or more	At least 90 lux for 2650 hours per year or more
Single storey buildings Occupied spaces (unless indicated below)		80%	At least 300 lux for 3000 hours per year or more	At least 120 lux for 3000 hours per year or more; or in spaces with glazed roofs (such as atria), at least 210 lux for 3000 hours per year or more
Prisons and courts buildings Cells and custody cells		80%	At least 100 lux for 3450 hours per year or more	N/A
Prison buildings Internal association or atrium areas		80%	At least 300 lux for 3250 hours per year or more	At least 210 lux for 3250 hours per year or more
Retail
Retail buildings Sales areas	1	50%	At least 300 lux point daylight illuminances for 2000 hours per year or more
Retail buildings Other occupied areas	1	80%	Select relevant criteria above for occupied spaces dependant on whether you are assessing a multi-storey or single- storey building.

Checklists and tables

Reflectance for maximum room depths and window head heights

The table below gives maximum room depths in metres for different room widths and window head heights of side-lit rooms.

Table 17 Reflectance for maximum room depths and window head heights

Reflectance (RB)	0.4		0.5		0.6
Room width (m)	3	10	3	10	3	10
Window head height (m)
2.5	4.5	6.7	5.4	8.0	6.8	10.0
3.0	5.0	7.7	6.0	9.2	7.5	11.5
3.5	5.4	8.6	6.5	10.4	8.1	13.0

Compliance notes

Ref	Terms	Description
Shell and core
CN1	Applicable assessment criteria	Glare control, criteria 1 to 2 Both options :These criteria are not applicable. Daylighting, criteria 3 and 14 Both options : All criteria relevant to the building type and function apply. View out, criteria 4 to 6 Both options: All criteria relevant to the building type and function apply. Internal lighting, zoning and occupant control, criteria 7 to 9, 11 to 13 Both options : These criteria are not applicable. External lighting, criteria 10, 13 Both options: All criteria relevant to the building type and function apply. Refer to Appendix D – BREEAM UK New Construction and Shell and Core Project Assessments for a more detailed description of the above shell and core assessment options.
CN1.1	Glare control	This compliance note has been removed as the Glare control credit is not applicable to Shell only and Shell and core assessments.
CN1.2	View out	Both options Where it is not possible to confirm which areas of the building will contain workstations/benches or desks, then all areas of the building designed for and/or likely to be occupied by workstations/benches or desks must comply with the relevant criteria.
Simple buildings
CN2	Applicable assessment criteria	All criteria relevant to the building type and function apply.
General
Glare control
CN3	Compliant forms of glare control - curtains as glare control	Compliant shading measures for meeting glare control credit include: building integrated measures (e.g. low eaves) occupant controlled devices such as blinds (where transmittance value is < 0.1 (10%)) bioclimatic design external shading or brise soleil. Glare control must provide shading from both high level summer and low level winter sun. Where using fixed systems, design studies can be used to demonstrate that sunlight is prevented from reaching building occupants during occupied hours. Curtains (where used without other forms of shading) do not meet the criteria for the glare control credit, as they do not provide sufficient control to optimise daylight in to the space. Furthermore, the use of curtains to control glare is likely to cause occupants to rely more on artificial lighting.
Daylighting
CN3.1	Percentage of assessed area See criterion 3.	Where the criteria specify that a percentage of floor area must be adequately illuminated by daylight, this refers to the percentage of the total floor area of all the rooms that must be assessed, i.e. the compliant area. If for example, a development has six rooms that must be assessed, each 150m² (total area 900m²) and 80% of this floor area must meet the criterion, then 720m² must comply with the criterion; this is equal to 4.8 rooms. The number of rooms that must comply must always be rounded up; therefore in this example, five rooms must have an average daylight factor of 2% or more (plus meet the other criteria) to achieve the credit. When using the point daylight factor to determine compliance for retail sales areas, the minimum percentage area should be based on the total floor area being assessed. Individual 'rooms' or sub areas do not need to meet the minimum thresholds. This is to allow for the typical building form restrictions and layout configurations that are necessary for these type of spaces.
CN3.2	External obstructions	In calculating minimum and average daylight factors and daylight illuminances, external obstructions should be taken into account. For illuminance calculations, the reflectance of external obstructions should be taken as 0.2 unless on-site measurements of external reflectance have been made.
CN3.3	Dirt factors when calculating daylight	Daylight calculations should include a maintenance factor for dirt on the windows, as given in British Standard Code of Practice for daylighting, BS8206 Part 2, appendix A1.3.
CN3.4	Borrowed light	For areas where borrowed light is used to demonstrate compliance with daylighting criteria, calculations or results from appropriate lighting design software must be provided to demonstrate that such areas meet the BREEAM criteria (if the light from these sources is required in order for the room to comply). Examples of borrowed light include: light shelves, clerestory glazing, sun pipes or internal translucent/transparent partitions (such as those using frosted glass).
CN3.5	Room depth criterion - rooms lit from two opposite sides	For rooms lit by windows on two opposite sides, the maximum room depth that can be satisfactorily illuminated by daylight is twice the limiting room depth (d) (measured from window wall to window wall; CIBSE Lighting Guide LG105CIBSE Lighting Guide LG10 Daylighting and window design, 1999.. The reflectance of the imaginary internal wall should be taken as 1.
CN3.6	Uniformity with rooflights	The room depth criteria cannot be used where the lighting strategy relies on rooflights. In such areas either appropriate software has to be used to calculate the uniformity ratio or, in the case of a regular array of rooflights across the whole of the space, figure 2.36 (page 37) within CIBSE Lighting Guide LG10 can be used to determine the uniformity ratio.
CN3.7	Daylighting - uniformity ratio Calculation	The uniformity ratio calculation, minimum point daylight factor and minimum daylight illuminance can exclude areas within 0.5m of walls. Areas within 0.5m are not regarded as part of the working plane for this purpose, although they are included in the average daylight factor and average daylight illuminance calculations.
CN3.8	View of sky requirement See criterion 3.	To comply with the view of sky criteria (ref (b)) in Table 11 , at least 80% of the room that complies with the average daylight factor requirement must receive direct light from the sky, i.e. it is permissible for up to 20% of the room not to meet the view of sky requirement and still achieve a compliant room.
Internal and external lighting levels/zoning and control
CN3.9	Relevant industry standard for lighting design	Pre-schools, schools and sixth form colleges: Building Bulletin 90: ‘Lighting Design for Schools’6Building Bulletin 90: ‘Lighting Design for Schools’ Please note that for care homes housing people with dementia the following standard can be used instead of the SLL Code for Lighting: Design Lighting for People with Dementia, University of Stirling, Stirling, 20137Pollock R, McNair D, McGuire B and Cunningham C, Design Lighting for People with Dementia, Dementia Services Development Centre, University of Stirling, Stirling, 2013. Please note that the illuminance levels specified in the SLL Code for Lighting, 2012 align with BS EN 12464-18BS EN 12464-1:2014 Light and lighting. Lighting of work places. Indoor work places, 2003.
CN3.10	Occupancy/ workstation layout unknown	Where occupancy or workstation layout is not known, lighting control can be zoned on the basis of 40m² grids, i.e. an assumption of 1 person/workspace per 10m².
CN3.11	Small spaces	Buildings consisting entirely of small rooms/spaces (less than 40m²) which do not require any subdivision of lighting zones/control will meet the zoning criteria by default.
CN3.12	Zones of four workspaces	The limit of four workspaces is indicative of the required standard but is not a fixed requirement. Where there is justification for this to be increased to fit with the adopted lighting strategy, this may be accepted provided that the assessor is satisfied that the aim of this criterion is upheld, i.e. that there is suitable zoning/control of lighting to enable a reasonable degree of occupant control over lighting in their personable work area. The relevant design team member, e.g. lighting consultant, should set out how this is to be achieved in such an instance.
CN3.13	Lighting zoning and control - auditoria spaces	The controls specified will depend on the size and use of the space but a typical auditorium or lecture theatre with stepped seating and a formal lectern/demonstration/performance area would typically be expected to have lighting controls as follows: Full normal lighting (to allow for entry/exit, cleaning etc.) Demonstration area lighting off and audience area lighting reduced to a low level (for the purpose of line slide projection, but allowing enough light for the audience to take notes) All lighting off (for the projection of tone slides, colour slides, and for the purposes of visual demonstrations/performances) Separate localised lectern lighting.
CN3.14	No external lighting	Where no external light fittings are specified (either separate from or mounted on the external building façade or roof), the criteria relating to external lighting do not apply and the credit can be awarded on the basis of compliance with the internal lighting criteria. The following internal areas are excluded from the lighting zone requirements: Media and arts production spaces Sports facilities (exercise spaces only, including hydrotherapy and physiotherapy areas).
Building type specific
CN4	Education - Education Funding Agency (EFA) requirements	For Education buildings, where the EFA daylighting requirements have been achieved, for all relevant rooms within the building (in accordance with Priority School Building Programme (PSBP) Authority Draft, Facilities Output Specification: Generic Design Brief by the Education Funding Agency, June 20139Priority School Building Programme PSBP Authority Draft, Facilities Output Specification: Generic Design Brief by the Education Funding Agency, June 2013), it can be assumed that the BREEAM daylighting requirements have also been met and therefore the two credits available for daylighting can be awarded by default. In this instance, evidence would need to be provided to demonstrate that the EFA requirements have been achieved.
CN4.1	Education (pre-schools) and acute Special Educational Needs (SEN) controls for children	Where child care and/or acute SEN spaces are included within the scope of the assessment, controls should be provided for the teacher/member of staff, i.e. it is not a necessity for the controls to be accessible to the children. Where nursery spaces are included within the scope of the assessment, controls should be provided for the member of staff, not the nursery school children.

Methodology

None.

Evidence

Criteria	Interim design stage	Final post construction stage
All	One or more of the appropriate evidence types listed in The BREEAM evidential requirements section can be used to demonstrate compliance with these criteria.
3, 4	Daylighting calculations	Refer to generic evidence requirement above

Additional information

Relevant definitions

Adequate view out

BREEAM defines an adequate view out as a view of a landscape or buildings (rather than just the sky) at seated eye level (1.2 – 1.3m) within the relevant building areas and should ideally be through an external window. A view into an internal courtyard or atrium will comply provided the distance from the opening to the back wall of the courtyard/atrium is at least 10m (therefore allowing enough distance for the eyes to refocus). The view cannot be an internal view across the room, as this is likely to become obstructed by partitions, filing cabinets etc.

Average daylight factor

The average daylight factor is the average indoor illuminance (from daylight) on the working plane within a room, expressed as a percentage of the simultaneous outdoor illuminance on a horizontal plane under an unobstructed CIE Standard Overcast Sky.

Clinical areas

Areas of the building in which medical functions are carried out that require specific restricted environmental conditions such as humidity, daylighting, temperature, etc. (e.g. X-ray, operating department, delivery room, etc.).

Computer simulation

Software tools that can be used to model more complex room geometries for daylighting.

Construction zone

For the purpose of this BREEAM issue the construction zone is defined as the site which is being developed for the BREEAM-assessed building, and the external site areas that fall within the scope of the new works.

Illuminance

The amount of light falling on a surface per unit area, measured in lux.

Occupied space

A room or space within the assessed building that is likely to be occupied for 30 minutes or more by a building user. Please note there is a specific, unrelated, definition of 'unoccupied' with reference to acoustic testing and measurement and this should not be confused with the definition used here.

Patient areas

Areas of the building used mainly by inpatients (e.g. wards, dayrooms, etc.).

Point daylight factor

A point daylight factor is the ratio between the illuminance (from daylight) at a specific point on the working plane within a room, expressed as a percentage of the illuminance received on an outdoor unobstructed horizontal plane. This is based on an assumed overcast sky, approximated by the ‘CIE (Commission Internationale de l’Eclairage) overcast sky’.
The minimum point daylight factor is the lowest value of the daylight factor on the working plane at a point that is not within 0.5m of a wall. Similarly the minimum illuminance is calculated at the worst lit point on the working plane that is not within 0.5m of a wall. These points will usually be close to a rear corner of the room. Computer simulations are the most appropriate tools to allow for point daylight factors and illuminances to be calculated.

Public areas

Within a Healthcare building type, this includes areas of the building designed for public use where no medical functions are carried out (e.g. reception, retail unit, waiting areas).

Relevant building areas:

Daylighting

For the purpose of BREEAM this is defined as areas within the building where good daylighting is considered to be of benefit to the building users (typically those areas occupied continuously for 30 minutes or more). This includes the following (where occupied continuously for 30 minutes or more) specifically stated because they are often omitted;

Sports hall exercise spaces
Laboratory areas unless the type of research that will be carried out requires strictly controlled environmental conditions, such as the exclusion of natural light at all times.
Self-contained flats
Kitchen and catering areas
General communal areas
Small offices (including those within multi-residential buildings)
Meeting rooms (including those within multi-residential buildings)
Leisure areas
Any area that may involve close up work.

However, this excludes the following (where present):

Media, arts production, SEN sensory spaces, x-ray rooms and other areas requiring strictly controlled acoustic or lighting conditions
Clinical areas with controlled environmental conditions, e.g. operating theatres, delivery rooms or pathology. However, BREEAM strongly advises that the benefits from daylighting and view out are seriously considered when designing areas of critical and intensive care in Healthcare buildings.
Holding areas and custody cells where security issues conflict with the BREEAM daylighting requirements
Custody cells in courts, where privacy is a functional/operational requirement.

Glare control

For glare control include areas of the building where lighting and resultant glare could be problematic for users, e.g. those areas that have been designed to contain/use workstations, projector screens etc. and sports halls. Spaces in the categories described above, for which daylight and view out are excluded, should not be assessed against the glare control criteria.

View out

BREEAM defines relevant building areas requiring a view out to include areas of the building where:

There are or will be workstations/benches or desks for building users.
Close work will be undertaken or visual aids will be used.
A view out is deemed to be of benefit to the building occupants, e.g. in spaces where occupants are likely to spend a significant amount of time.

Excluded areas for each of these might include:

Nurse bases where they are located centrally in a ward/patient area in order to enable patient observation.
Courtrooms and interview rooms where compliance is not possible due to security or privacy criteria.
Prison staff areas containing workstations that for security or observational purposes must be located centrally within the building.
Any clinical areas where the control of environmental/operational conditions prevents such spaces from providing a view out.
Conference rooms, lecture theatres, sports halls, acute SEN and also any spaces where the exclusion or limitation of natural light is a functional requirement e.g. laboratories, media spaces, etc.

Internal and external lighting

Where no external light fittings are specified (either separate from or mounted on the external building façade or roof), the criteria relating to external lighting do not apply and the credit can be awarded on the basis of compliance with the internal lighting criteria. The following internal areas are excluded from the lighting zone requirements:

Media and arts production spaces
Sports facilities (exercise spaces only, including hydrotherapy and physiotherapy areas).

Lighting zoning

For rooms or spaces not listed within criterion 12, the assessor can exercise an element of judgement when determining whether the specification is appropriate for the space given its end use, and the aim and criteria of this BREEAM issue.

Separate zoning control

Light switches or controls for a particular area/zone of the building that can be accessed and operated by the individual(s) occupying that area or zone. Such controls will be located within, or within the vicinity of, the zone or area they control.

Staff areas

Areas of the building used mainly by staff (e.g. offices, meeting rooms, staff rooms) and medical areas where patients are admitted but that do not require restricted environmental conditions (e.g. consulting rooms, physiotherapy, etc.).

Surrounding wall area

Surrounding wall area refers to the area (in m²) of the internal wall on which the window/opening is located, including the area of the window/opening itself.

Uniformity

The uniformity is the ratio between the minimum illuminance (from daylight) on the working plane within a room (or minimum daylight factor) and the average illuminance (from daylight) on the same working plane (or average daylight factor).

View of sky/no-sky line

Areas of the working plane have a view of sky when they receive direct light from the sky, i.e. when the sky can be seen from working plane height. The no-sky line divides those areas of the working plane, which can receive direct skylight, from those that cannot.

Working plane

CIBSE LG10 defines the working plane as the horizontal, vertical or inclined plane in which a visual task lies. The working plane is normally taken as 0.7m above the floor for offices and 0.85m for industry.

Other information

None.