Page 30 - GRIHA Manual Volume V - Introduction to National Rating System

Evaluation procedure 23

CRIteRIon 5

ReduCe HARd pAvInG on-sIte
And/oR pRovIde sHAded

HARd-pAved suRfACes

GRIHA-speciic information

Objective

to reduce hard paving on-site (open areas surrounding building premises) and/or provide shade
on hard-paved surfaces to minimize the heat island effect and imperviousness of the site.
5.1 Commitments

5.1.1 net paved area of the site under parking, roads, paths, or any other use not to exceed
25% of the site area or net imperviousness of the site not to exceed the imperviousness
factor as prescribed by the national building Code of india, bureau of indian Standards,
2005; Part 9 (Plumbing services) Section 5.5.11.2.1, whichever is more stringent.
5.1.2 total surface parking not to exceed the area as permissible under the local bye-law and
# more than 50% of the total paved area to have previous paving/open grid pavement/
grass pavers, or
# a minimum 50% of the total paved area (including parking) to have shading by
vegetated roof/pergola with planters, or
# a minimum 50% of the total paved areas (including parking) to be topped with finish
having solar reflectance of 0.5 or higher.

combination
a minimum of 50% of the total paved area to have any combination of above mentioned strategies
for pervious paving shaded paved area or area with Sri > 50% where common area having 2 or
more strategies shall be calculated only once.

Table 5.1 Run-off coeficient for various surfaces
Surface type Run off coeficient
Roofs (conventional) 0.95
Roof garden <100 mm thick 0.50
Roof garden 100 –200 mm thick 0.30
Roof garden 200 -500 mm thick 0.20
Roof garden >500 mm thick 0.10
Concrete/Kota Paving 0.95
Gravel 0.75
Brick Paving 0.85