Specialty & Green Systems
Blue Roof (Water Detention)
Top brand: Custom Engineered
Installed cost
$17.70–$35.40
CAD per sq ft
Lifespan
25–40 yrs
manufacturer typical
Region
Lower Mainland
+18% CAD adjustment
Overview
Engineered to temporarily detain rainfall — usually using a controlled-flow drain — to reduce peak storm-sewer loading. Common on Vancouver mid-rises subject to stormwater bylaws.
Best for
Mid-rises required to throttle peak stormwater discharge.
Live cost estimate
Estimate your Blue Roof (Water Detention) roof
Lower Mainland installed pricing in CAD. Drag the slider to match your roof area.
500 sq ft8,000 sq ft
Low
$35,400
Typical
$53,100
High
$70,800
Range: $17.7 – $35.4 per sq ft installed. Includes tear-off, underlayment, flashing, and labour. Excludes permits, structural work and tax.