Suburban Green Roof

Tommy, Kenny, Gary

Introduction

• Urban Sprawl

http://lal.cas.psu.edu/Research/sprawl.html

Cont’d

• Cramped Spaces

Reasons for Suburban Green Roof

• lot size, sunlight restriction, limited vegetation, environment

Front Back

Before & After

Suburban Green Roof

• Will increase green space• Maximize sunlight• Increase variety of vegetation

• Help filter the air• Reduce runoff• Lower green house gas• Save money in the long run• More will be discussed later on….

Implementing

Issues : Structural

Issues : Safety

Issues : Micro-Climate

Preferred plant list :

Sedum acre ‘Aureum’

Sedum album

Sedum album ‘Murale’

Sedum floriferum ‘Weihenstephaner Gold’

Sedum kamtschaticum

Sedum reflexum

Sedum sexangulare

Sedum spurium ‘Fuldaglut’

Sedum spurium ‘Roseum’

Sedum ‘John Creech’

Talinum calycinum

Issues : Permit/Inspection

Benefits of green roof

• storm water management • water filtration • visual enhancement• heating and cooling • greenhouse effect• urban biodiversity • roof life extension• sound reduction • air quality improvement • urban heat island effect• urban ecology

Important Statistic

• Storm water management plays a major role in terms of landscaping and city planning. Green roof can directly reduce (50-10%) rate of storm water runoff by absorbing water into the roof membrane and not overcome municipal sewage system[1].

Cont’d

• According National Research Council (NRC) in Ottawa, in 2001 during a hot summer day a normal conventional roof has a record of 70ºC while green roof has a record of 25ºC to 30ºC. In reference, it is approx 40ºC to 45ºC difference between conventional and green roof.

Cont’d

• The roof’s medium will infiltrate and reduce 66% of heat from ultraviolet; therefore it will extent the life of a roofline much longer. According to a study in Germany, a green roof will have double life span service than a conventional roof by 20 years

Maintenance of green roof:

• Target to be a low maintenance and stress-free roof

• Require very little watering

• Once the roof is established in period of time, trimming and weeding is necessary to maintain the green roof healthy

Total cost of green roof

• Area of extensive green roof = 630 sq ft • Re-roofing with root-repelling membrane ($ 10.00 - $ 15.00

per s.f.) = $ 6300 to $ 9450

• Green roof system (curbing, drainage layer, filter cloth and growing medium): ($ 5 - $ 10 per s.f.) = $ 3150 to $ 6300

• Plants: $1-$13 = $630 to $1890

• Installation / Labour: ($3 to $8 per s.f) = $1890 to $5040

• Maintenance: ($1.25 to $2.00 per s.f.) = $787.50 to $1260

Total Cost

• Total cost excluding (design & specifications and project administrative & site review)

Approximately

= $13000 to $24000