The most important characteristics of pavers are:
- the pavers are pervious. Impervious surfaces cause environmental problems by causing increased storm-water runoff. This additional runoff can overwhelm storm-water systems and cause flooding and pollution of steams and waterways.
- the pavers have a high Solar Reflectance Index (SRI). High SRI pavers do not reflect heat back into the environment or into buildings increasing heating loads.
The most common types of green pavers are:
- Open Grid Pavers - (Open grid pavers is pavement that is less than 50% impervious and allows moisture to pass through the material and soaks the earth below the paving system. These pavers resemble a grid where the open area can can filled with gravel or is has mulch or grass growing through. These support the weight of cars and can be used for driveways.
- Interlocking Concrete Pavers- Interlocking concrete pavers have openings between individual pavers comprising 10-15% of the surface area. The open area is filled with highly permeable, small-sized aggregates.
- High SRI pavements - High SRI Pavements reflect a high percentage of the heat from sunlight. Materials with the highest SRI are the coolest and are the most appropriate choice for reducing the heat island effect. The heat island effect can increase air conditioning loads in buildings near low SRI pavers.