How much does a green roof cost?

Depending on type of plants, total size of project, roof top design, building location and height, our green roofs typically range from $10-$20 per foot installed.

What’s the cost recovery or ROI?

There are several variables to consider, so each case is different. When you consider the energy savings, reduced roof maintenance, extended roof life and in some cases tax credits and grant money available, it’s safe to say that in most cases, a green roof will pay itself off within 5-7 years.

What’s so special about the LiveRoof® system?

LiveRoof® represents the best aspects of modular and conventional green roofs combined in one simple, attractive effective system. LiveRoof® is an integrated system designed by growers in conjunction with experts in the fields of architecture, roofing, logistics, and ergonomics. It is earth-friendly, as well as rooftop functional and aesthetically pleasing.  LiveRoof® systems, because they are pre-vegetated at the nursery, require minimal maintenance.  Compared to site-built green roofs, which are time-consuming and costly to install and maintain, LiveRoof® offers a turn-key alternative that doesn’t require you to be a horticulturist.  LiveRoof® modules can be vegetated with various plant assortments to address your particular design needs and climate.  And if there is ever any need to make changes to the roof, LiveRoof® modules are easily moved aside and replaced after the work is done.

What are the biggest financial benefits?

1. Extended roof life and reduced maintenance. By protecting the rooftop from ultraviolet radiation, large temperature fluctuations, drying winds, and  punctures, a green roof can double the life of a roof. There is also reduced membrane maintenance. 

2. Significant energy savings. Green roofs have been proven to bring about significant energy savings, particularly during the summer in which a single story building can experience a reduction of 25%-30% in energy use. In addition, plants transform heat and soil moisture into humidity, to create natural evaporative cooling.

How much does the LiveRoof® system weigh?

The LiveRoof® system weighs approximately 10-29 lbs/foot depending on system and water retention.

Can I retrofit my existing building?

It depends on the load capacity of the existing building.  Also, some older buildings can be redesigned for the additional weight of the LiveRoof® modules.   A qualified engineer must always conduct a thorough analysis.

Does LiveRoof® need irrigation?

The need for irrigation (beyond normal rainfall) will depend upon the plants selected, the local climate, and specific weather patterns.  Under normal circumstances, supplemental irrigation is seldom if ever required.  Even so, we suggest a backup irrigation system in the event of prolonged hot, dry, windy, sunny weather.  During very long bouts of dry weather, plants can go dormant, shrink up, and expose soil. This can increase maintenance requirements as weeds can become established in bare soil. Excessively dry soil also causes the evapotranspirative cooling effect of the green roof to be reduced.  
             
Irrigating, even once per month during protracted dry weather, can keep your green roof looking its best and pay dividends through maintenance reductions and evaporative cooling. Irrigating during protracted hot dry weather is a personal choice, the cost is minimal and one has the piece of mind that if ever needed, the water will be there. Backup irrigation systems can range from spigot and hose to overhead irrigation (similar to what one might have in one’s yard.)

What are the best plants to use with the LiveRoof® System?

Those that have extreme drought resistance through some means other than the root system.  This means succulent, water-holding plants like Sedums, Alliums, Sempervivums, Delospermas and a few others.  The best LiveRoof® plants will both store water and have a special type of metabolism called ‘Crassulacean Acid Metabolism’, CAM for short.  CAM plants are unique in that under drought conditions their stomates (leaf pores) are open at night rather then during the day, as is the case with most plants.  CAM plants exchange gasses (oxygen and carbon dioxide) in the dark when it is cooler and less windy.  CAM plants are up to ten times more efficient with water conservation than non-CAM plants.

LiveRoof® plants have been selected for extreme drought tolerance, disease and insect resistance, long life, low maintenance, and beauty.  LiveRoof® plants are planted in the LiveRoof® modules at Hortech and other nurseries and cared  for until shipped to the job site.  Plants are selected by local horticulturists in order to meet the above objectives as well as the local climate and customer preferences.

How does a green roof help mitigate urban heat island effect?

Traditional rooftops are usually covered with tar, shingles or stone,  And as a result, absorb sunlight.  On sunny days with an air temperature of 95°F, city roofs can easily reach temperatures of 175°F or more.  The LiveRoof® system acts like a protective umbrella above the roof to shade and insulate buildings, avoiding the heat island effect associated with traditional rooftops.

Plants, of course, release oxygen and evaporate water, a process known as evapotranspiration, and act like evaporative cooling systems to make the air surrounding them considerably cooler.  By implementing a LiveRoof® system, the combined benefit of eliminating the heat generated by a non-vegetated rooftop, along with the evaporative cooling effect, is significant.

How does the LiveRoof® system reduce storm water runoff?

In urban areas, impermeable surfaces (streets, sidewalks, rooftops etc.) dominate the landscape, preventing rainwater from following a natural cycle of absorption.  Instead, as much as 75% of the rainwater runs into sewer systems.  Carrying contaminates from the air and roadways (salt, oil, mercury, etc.), this water flows untreated into lakes and streams.  In some cases, it may cause overflows of sanitary sewer systems, causing the dumping of untreated sewage.  In contrast, LiveRoof® green roof surfaces can absorb up to 99% of a 1”  rainfall, reduce runoff, lessen the risk of sewer overflows and flooding, and to some degree filter the water as it percolates through the LiveRoof® soil.  Even when a rainfall is such that it can not all be absorbed by your LiveRoof®, the excess rain that runs through the media is filtered and delayed until after peak flows, which allows additional time for sanitary sewer systems to handle uncontrolled runoff.

Can you install on a sloped roof?

LiveRoof® works well on low-sloped (non-pitched) roofs, on industrial, commercial, institutional, governmental and residential buildings. 

Can the LiveRoof® system be used in nonroof areas?

Certainly—median strips, patios, plazas, and malls are also great opportunities to use the LiveRoof® system.

Can I lift up a LiveRoof® module if I want to access my roof?

Yes, it’s relatively easy. First, using a flat bladed shovel, probe the planting to locate the container edge. Then peel away some plant material. This is easy to do as the root systems of LiveRoof® plants is fibrous and easy to separate (not at all like sod). Using a sturdy pair of pliers, lift up and remove the exposed module. Any additional modules may be removed by trimming around them with the handle of a spoon and lifting them up. Once you are finished, replace the modules. Note: Never use sharp intruments around roof membranes.

Are there financial incentives available for green roofs?

As energy demands rise and smog and other pollution impacts our cities, many cities and states are encouraging “green” building methods, including green roof systems.  Cities also encourage green roofs to reduce storm water surges, to protect the ground water, lakes, and streams, and to conserve energy.

Of course, incentives vary from city to city and state to state, but it is not uncommon for owners of buildings with green roofs to be generously rewarded. Cities all across North America are following suit, and grant money is often available for the energy conservation and air and water quality benefits that green roofs bring.

States and municipalities benefit greatly from green roofs, and often provide tax credits, avoidance of fees assessed for impervious surfaces, grant funding, and/or favorable zoning to encourage their development.

What about maintenance after the green roof is installed?

We offers maintenance on all roof top projects we install that includes monthly weeding and inspections, year end plant care. This low cost service (10-20 cents per foot) ensures your living investment is always in the best of health.