Page 68 - GRIHA Manual Volume V - Introduction to National Rating System
P. 68
Evaluation procedure 61
5) Provide the calculated ShgC in the prescribed format for window details (table 13.4) to
support that all proposed fenestration meet the ShgC requirement as prescribed in eCbC
2007.
6) Certificate from architect/ service consultant on compliance with clause 13.1.4.
Review checklist
1) review the calculations of window to wall ratio (wwr) and the skylight to roof ratio (Srr)
and check if they are as per the limits prescribed in eCbC 2007.
2) review the calculations of effective ShgC to see if it has been calculated as per the procedure
prescribed in eCbC 2007. to ensure that the projection factor calculation has been done
correctly and correct multiplication (m) factor has been used, use the ShgC calculator to
cross check the calculations for a few sample cases.
Possible errors
1) the calculations for wwr and Srr may not have been done correctly. the wall area taken
for wwr calculation may not be the gross wall area. for example, sometimes wall/window
as seen in a particular elevation is taken instead of gross wall area.
2) Calculation of the effective ShgC may have been done erroneously. the effective depth
of the shading device or the value taken for the critical solar angle on the façade may be
incorrect.
3) glass cut sheet values may not match the values in the tables.
Point allocation
two mandatory points should be awarded if appropriate climate responsive strategies have been
adopted in the building design, wwr and Srr are as per the limits prescribed in the eCbC and all the
fenestrations meet the ShgC requirement of the eCbC.
Appraisal 13.3.2
minimum 25% of the living area (as mentioned above) should be daylighted and adequate level of
daylight is provided as prescribed by iS code as per clauses 13.2.6 and 13.2.8 (2 points – mandatory)
and/or
# if the total daylighted area > 50% of total living area (1 point – additional) and/ or
# if the total daylighted area > 75% of total living area (1 point – additional)
Required documentation
1) Calculated daylighted area in the prescribed format and the calculated daylight factor (df)
in the format for daylight factor calculation. total daylighted area should be > 25% of the
living area of the proposed building. the calculated df is to demonstrate that all the living
areas compliance with iS: 2440-1975.
Review checklist
1) review the daylight area calculation and check the percentage of daylighted area of the
total living area.
2) Check if the recommended daylight factor (df) has been achieved.
5) Provide the calculated ShgC in the prescribed format for window details (table 13.4) to
support that all proposed fenestration meet the ShgC requirement as prescribed in eCbC
2007.
6) Certificate from architect/ service consultant on compliance with clause 13.1.4.
Review checklist
1) review the calculations of window to wall ratio (wwr) and the skylight to roof ratio (Srr)
and check if they are as per the limits prescribed in eCbC 2007.
2) review the calculations of effective ShgC to see if it has been calculated as per the procedure
prescribed in eCbC 2007. to ensure that the projection factor calculation has been done
correctly and correct multiplication (m) factor has been used, use the ShgC calculator to
cross check the calculations for a few sample cases.
Possible errors
1) the calculations for wwr and Srr may not have been done correctly. the wall area taken
for wwr calculation may not be the gross wall area. for example, sometimes wall/window
as seen in a particular elevation is taken instead of gross wall area.
2) Calculation of the effective ShgC may have been done erroneously. the effective depth
of the shading device or the value taken for the critical solar angle on the façade may be
incorrect.
3) glass cut sheet values may not match the values in the tables.
Point allocation
two mandatory points should be awarded if appropriate climate responsive strategies have been
adopted in the building design, wwr and Srr are as per the limits prescribed in the eCbC and all the
fenestrations meet the ShgC requirement of the eCbC.
Appraisal 13.3.2
minimum 25% of the living area (as mentioned above) should be daylighted and adequate level of
daylight is provided as prescribed by iS code as per clauses 13.2.6 and 13.2.8 (2 points – mandatory)
and/or
# if the total daylighted area > 50% of total living area (1 point – additional) and/ or
# if the total daylighted area > 75% of total living area (1 point – additional)
Required documentation
1) Calculated daylighted area in the prescribed format and the calculated daylight factor (df)
in the format for daylight factor calculation. total daylighted area should be > 25% of the
living area of the proposed building. the calculated df is to demonstrate that all the living
areas compliance with iS: 2440-1975.
Review checklist
1) review the daylight area calculation and check the percentage of daylighted area of the
total living area.
2) Check if the recommended daylight factor (df) has been achieved.
