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IEQ-5 DAYLIGHT GLARE CONTROL

 

Technical Clarification
Solid opaque blinds
Technical Clarification Number
IEQ5-T-OB1-1686

(replaces IEQ5-T-OB1-612)


Guidance
2016-11-15
The GBCSA confirm that for the purposes of proving compliance with the IEQ-5 Daylight Glare Control credit, solid (not perforated or woven) opaque blinds such as solid metallic or solid timber blinds can be assumed to have a VLT of < 10%. Confirmation from the manufacturer or manufacturers datasheets detailing the nature of the material component must be provided in the submission however and this assumption clearly stated referencing this Technical Clarification.

Similarly, in most instances ‘block-out’ fabric blinds will also have a VLT < 10%. Where the VLT of the block-out fabric product is unknown, project teams may provide documentation from the supplier merely showing that the fabric is being marketed as “block-out” fabric and no VLT information is required.

 

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Credit Interpretation Request

Manual override of automated blinds with a monitoring system may be omitted

Credit Interpretation Request Number
IEQ5-T-OB1-1359

Guidance
2016-04-05

The GBCSA confirm that: 

Manual override of automated blinds with a monitoring system may be omitted on the basis that the project team demonstrates that the automation and monitoring system in combination with the particular blind design can meet the aim of the credit without intervention from occupants.

It would be expected that the system is able to keep direct sunlight off occupants in the designated UA during daylight hours via the physical design of the blinds, and that the automation as well as the monitoring system ensure that the blinds are operating as intended (are in the correct position per the time of day and or year.) If the system does allow direct sunlight to pass into the occupied area for any design reasons (e.g. directing solar gain onto the ceiling in winter to reduce space heating) it should be demonstrated that the system can be adapted to future tenants, adjustment in furniture layouts to ensure the glare control requirements can still be met. It is to be noted that the blinds still need to meet the current glare control requirements expected of manual control blinds with regards to transmission of materials and the amount of light passing between framing and the blinds.

Documentation Requirements:

Short Report - The short report must detail the nature of the blind system, including the physical blinds as well as the automation and the monitoring system referencing relevant contractual project documentation. It must be demonstrated that 95% of all direct sun penetration will be  avoided without intervention from occupants.

Extracts from Specifications (Design Rating) - Contract documentation must clearly indicate the inclusion of the automation and monitoring system as described in the Short Report.

Extracts from Commissioning Report (As Built Rating) - confirming that the blind system including automation and monitoring has been commissioned and is operating as intended by the design.

Extracts from the O&M manuals (As Built Rating) - indicating how the system would need to be reprogrammed to adjust to new conditions if and when required.

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Technical Clarification

Clarification of extent of blinds/fixed shading required

Technical Clarification Number
IEQ5-T-OB1-0817

Guidance
2015-09-16

The GBCSA confirm that: 

  • 100% of the windows within the Usable Area (UA) requires fixed shading when following this route to compliance. Windows that do not fall within the UA do not require fixed shading.
  • 100% of the windows within the Usable Area (UA) requires blinds when following this route to compliance. Windows that do not fall within the UA do not require blinds.

 

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Technical Clarification

Definition of VLT vs TV

Technical Clarification Number
IEQ5-T-OB1-0662

Guidance
2013-04-23

The GBCSA notes that for the purposes of Green Star SA, the terms Visual light transmittance (VLT) and Visible transmittance (TV) can be used interchangeably as they refer to the same concept (i.e. the amount of light in the visible portion of the spectrum that passes through a glazing material)

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Technical Clarification

Solid opaque blinds

Technical Clarification Number
IEQ5-T-OB1-612

Guidance
2013-01-07

The GBCSA confirm that for the purposes of proving compliance with the IEQ-5 Daylight Glare Control credit, solid (not perforated or woven) opaque blinds such as solid metallic or solid timber blinds can be assumed to have a VLT of < 10%. Confirmation from the manufacturer or manufacturers datasheets detailing the nature of the material component must be provided in the submission however and this assumption clearly stated referencing this Technical Clarification.

Similarly, in most instances ‘block-out’ fabric blinds will also have a VLT < 10%. For ‘block-out’ fabric blinds, where the VLT of the material is not known, project teams can confirm through Technical Clarification (TC) that the material composition is similar in nature to another fabric with a known VLT < 10%. Confirmation from the manufacturer or manufacturers datasheets detailing the nature of the material component must be provided within the TC submitted.

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Credit Interpretation Request

Alternative credit criteria compliance methodology

Credit Interpretation Request Number
IEQ5-C-OB1-0311

Ruling
2012-01-10

The Credit Interpretation Request (CIR) seeking approval for a proposed alternative credit criteria compliance methodology is conditionally granted.

The CIR Review Panel opinion is that the use of architectural modelling software and associated pulg-in programs (e.g. Google Sketch-Up and 1001Shadows) to demonstrate compliance with the credit criteria is deemed acceptable as many 3D CAD packages have the ability to draw shadows at any time based on the sun path. Therefore such programs have the potential to assess the hours a given point is in sunligh for the purposes of this credit.

However such programs often lack the functionality of assessing a point for a detailed time schedule or period (i.e. yearly working ours, as available in more advanced solar analysis programs). To minimise non-automated computation time, it is an acceptable approximation that the analysis of a point be evaluated on discrete reference days which are representative of the variation in vertical solar angle during different seasons. An average may then be taken of the reference days analysed.

The CIR Review Panel conditionally grant this alternative compliance methodology.on condition of the following requirements:

- The methodology is applied to each window/glazing element with a whole building model only (i.e. not individual models of windows/glazing elements). This is to account for the impact of adjacent windows/glazing elements and the intrusion of direct daylight on the adjoining analysis point on facades where low-angle sun is prevalent;
- The methodology is applied to façade windows/glazing elements only. It is not acceptable to assess clerestory windows or roof lights. If such elements exist, an alternative methodology is must be proposed by CIR and approved separately;
- The analysis dates are the summer solstice, winter solstice and either autumn or spring equinox, with average of the three results deemed as the annual average for the purpose of demonstrating compliance with the credit criteria.

The CIR Review Panel intention of this CIR is to enable a broader range of software packages to be used for the purpose of demonstrating compliance with the credit criteria.

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Technical Clarification

Green Star SA - Office v1 Technical Manual: Page 67

Technical Clarification Number
IEQ5-E-OB1-0158

Guidance
2011-01-06

Credit Criteria, second bullet point, change "Eliminate all direct sun penetration" to "Eliminate 95% of all direct sun penetration".

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Erratum

Green Star SA - Office v1 Technical Manual: Page 68

Erratum Number
IEQ5-E-OB1-0152

Guidance
2011-01-06

Documentation Requirements, documentation description, under the heading "Short Report," third bullet point, change "describing how all direct sun penetration will be avoided" to "describing how 95% of all direct sun penetration will be avoided".

 

Erratum

Green Star SA - Office v1 Technical Manual: Page 68

Erratum Number
IEQ5-E-OB1-0159

Guidance
2011-01-06

Documentation Requirements, under the heading "Occupant controlled, automated blinds/screens," second bullet point, change "prevent all direct sunlight penetration" to "prevent 95% of all direct sunlight penetration".

 

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Erratum

Green Star SA - Office v1 Technical Manual: Page 67

Erratum Number
IEQ5-E-OB1-0160

Guidance
2011-01-06

Documentation Requirements, under the "Fixed Shading" heading, delete "The business day of 8am to 6pm is to be used for calculating 80% of the standard occupancy hours".

 

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Technical Clarification

Definitions - "occupied hours”, “standard hours of occupancy” and "standard working hours"

Technical Clarification Number
IEQ5-T-OB1-0110

Guidance
2010-11-02

For the purpose of this credit, “occupied hours”, “standard hours of occupancy” and "standard working hours" are defined as equivalent and equal to the operational profile of the ‘HVAC plant’ as detailed in the applicable Energy Calculator & Modelling Protocol Guide. This definition is applicable to both mechanically ventilated spaces and naturally ventilated spaces (irrespective of the inclusion of HVAC plant or not). Please note these definitions do not amend the ‘Occupancy’ profiles as defined in the applicable Energy Calculator & Modelling Protocol Guide.

 

Credit Interpretation Request

Calculation methodology

Credit Interpretation Request Number
IEQ5-C-OB1-0081

Ruling
2010-06-10

The Credit Interpretation Request (CIR) seeking to use the sunlight hours methodology in place of stereographic diagrams is approved conditionally, as long as the following criteria are demonstrated. The project must set up a grid at desk height (720mm AFFL) starting 1.5 metres in from all glazing (or any source of natural light) and extending throughout the floor plan on a 1m x 1m maximum grid, to 1.5 metres from all daylight sources. All grid points 1.5m and further in must be shaded from direct sun for 80% of standard working hours. Projects must provide output indicating values for every grid point, clearly demonstrating compliance. Projects are encouraged to provide a coloured grid with grid colours scaled to indicate where compliance is and is not achieved, demonstrating that any points where compliance is not achieved are outside the required calculation zone. It must be clear that all sources of natural light have been accounted for, including skylights and atria.

 

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Technical Clarification

Manual blinds

Technical Clarification Number
IEQ5-T-OB1-0071

Guidance
2010-05-21

In addition to the Credit Criteria stated in the technical manual, the following additional credit criteria have been developed. Projects using the following criteria can claim one point for this credit. This criteria can be used in conjunction with the criteria stated in the technical manual, or by itself.

One point is awarded where it is demonstrated that glare from daylight is reduced through the fitting of blinds or screens on all glazing and atria as a base building provision and meet the following criteria:
- Eliminate 95% of all direct sun penetration; AND
- Have a visual light transmittance (VLT) of ≤10%; AND
- Can be controlled by all affected occupants within each floor or area.

Projects seeking to claim this alternative methodology must use the documentation requirements for Occupant Controlled, Automated Blinds/Screens as stated in the credit criteria, with the exception of the provision of an automated motorized control for these blinds.

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Credit Interpretation Request

Direct sun penetration CORRECTION

Credit Interpretation Request Number
IEQ5-C-OB1-0065

Ruling
2010-05-13

The requirement to eliminate all direct sun penetration for this credit has been modified. Where the second bullet point of the credit criteria (for blinds or screens) states "eliminate all direct sun penetration" must be changed to "eliminate 95% of all direct sun penetration". This change accounts for the need to allow a small sliver of light to enter between the wall and the edges of the blind.

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Credit Interpretation Request

Tinted Glazing

Credit Interpretation Request Number
IEQ5-C-OB1-0067

Ruling
2010-05-12

The Credit Interpretation Request (CIR) to deem the combination of tinted glazing and fixed shading devices, which are shown to be effective via a daylight glare model, equivalent to the credit criteria, is granted conditionally on the project’s ability to demonstrate that the solution, as designed and built, will result in a reduction of glare to the user equivalent to that which is stated in the credit criteria.
Projects must submit a CIR that shows how the specific solution is equivalent to meeting the Credit Criteria. The documentation submitted with the CIR must show:
- The methodology used to create the daylight glare model and the software used;
- How the selected points represent the areas that would be effected by glare;
- That all terms are clearly defined within the report;
- The Name, type, glazing properties, and location of glazing (please ensure that this is clear); and
- How the results in the model are equivalent to that of the Credit Criteria in the Technical Manual.

Projects using this methodology must show that the above requirements are met in the documentation. Please ensure that all documentation is clearly correlated and highlighted.

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