Green Roof Design

Transform your building into a beautiful, sustainable oasis with our expert green roof design services. Our team specializes in creating customized designs that not only absorb stormwater and reduce the urban heat island effect but also enhance the livability and functionality of your space. Whether you’re looking for a simple sedum roof or a complex rooftop farm, we have the expertise to make your vision a reality. And with our comprehensive services, including preliminary design, comprehensive design, and construction management, we’ll be with you every step of the way, ensuring a seamless and stress-free process. Don’t settle for a dull, conventional roof – choose our firm and experience the benefits of a beautiful, sustainable green roof today. Over the last decade, we have watched countless cities pass legislation promoting green roofs as a tool for stormwater management (delay, rate reduction, and volume reduction).

Built-in-place green roofs involve installing a growing medium and vegetation directly onto the roof surface. This approach allows for more customization and flexibility in terms of the shape and size of the green roof, as well as the type of vegetation that can be planted. However, it also requires more time and effort to install and can be more expensive. In general, built-in-place green roofs are better suited for larger, more complex roof structures, and may be preferred in situations where a specific plant selection or design is desired.

Modular green roofs, on the other hand, consist of pre-fabricated panels that are assembled on the roof surface. This approach is quicker and easier to install than built-in-place green roofs and can be more cost-effective. However, it may be more limited in terms of customization options, and may not be suitable for roofs with complex shapes or slopes.  In general, modular green roofs are a good option for smaller or simpler roofs, and may be a better fit for buildings with limited access to the roof or where time and cost are major considerations.

Options

Ground Cover
  • Moss, creeping thyme, clover, silver carpet, aloe
  • Shallow roots, drought-tolerant, good coverage, insulates the building, reduces stormwater runoff
Sedums
  • Many varieties and coverage types that are natives, maintenance-free, low growing
  • Low maintenance, can tolerate harsh environmental conditions such as high temperatures and low rainfall, shallow roots. Drought-tolerant plants that store water in their leaves
  • Agave, Aloe, Sedum (flowering plant known as stonecrop), Sempervivum
Colorful Pollinator-Friendly Flowers
  • Coneflowers, Black-eyed Susan, Daylilies, Lavender
  • Adds aesthetic appeal and colorful beauty to gardens
  • Echinacea purpurea, Rudbeckia hirta, Hemerocallis sp., Lavandula angustifolia
Herbs
  • Creeping rosemary, thyme, balm, mint, basil
  • Edible, pleasant aroma, attracts beneficial insects such as bees and butterflies. Used in cooking, medicine, and aromatherapy
  • Rosmarinus officinalis, Thymus vulgaris, Melissa officinalis, Mentha sp., Ocimum basilicum
Herbaceous Grasses
  • Big bluestem, little bluestem, switchgrass, purple lovegrass, prairie dropseed, muhly grass, feather reed grass, blue oat grass
  • Deep roots for erosion control, can reduce ambient temperatures, creates habitat for birds and insects, good for biodiversity
  • Andropogon gerardii, Schizachyrium scoparium, Panicum virgatum, Eragrostis spectabilis, Sporobolus heterolepis, Muhlenbergia capillaris, Calamagrostis x acutiflora, Helictotrichon sempervirens
Rooftop Farms
  • Tomatoes, peppers, lettuce, herbs such as basil and parsley
  • Enables growing fresh produce in urban areas where space is limited
  • Requires more maintenance and attention than other green roof options
Fire-resistant vegetation
  • Plants that can reduce the risk of fires and provide a natural buffer zone
  • Reduces the risk of fires, provides insulation for the building
  • Arctostaphylos sp., Ceanothus sp., Chrysolepis chrysophylla
Next-generation beehive
  • Innovative and easy-to-use beehives that don’t require beekeepers and support local bee populations while harvesting honey
  • Supports local bee populations and honey production, easy to use and maintain
  • Flow Hive, BEEcosystem, B-Box Hive

Types

Intensive
  • Also known as a “roof garden,” this type of green roof has a deeper soil layer and allows for a wider variety of plant types, including trees and shrubs. It requires more maintenance and irrigation than other types of green roofs.
  • Trees, shrubs, perennials, annuals, vegetables, and herbs
  • Soil Depth (Inches): 10 to 24
  • Load Bearing Capacity (lbs/sf): 100 to 150
  • Provides the most insulation, improves air quality, reduces stormwater runoff, and creates usable space for gardens or recreational areas.
Semi-intensive
  • This type of green roof has a moderate soil layer and a mix of plant types, including perennials, groundcovers, and some shrubs. It requires less maintenance than an intensive roof but more than an extensive roof.
  • Perennials, groundcovers, some shrubs
  • Soil Depth (Inches): 6 to 10
  • Load Bearing Capacity (lbs/sf): 50 to 100
  • Provides some insulation, improves air quality, reduces stormwater runoff, and can create usable space for gardens or recreational areas.
Extensive
  • This type of green roof has a shallow soil layer and is planted with low-maintenance, drought-tolerant plants such as sedums and grasses. It requires the least amount of maintenance and irrigation of all green roofs.
  • Soil Depth (Inches): 3 to 6
  • Sedums, grasses, herbs
  • Load Bearing Capacity (lbs/sf): 10 to 50
  • Provides some insulation, improves air quality, reduces stormwater runoff, and requires minimal maintenance.

Benefits

  • Increase the durability and lifespan of your roof by 300% and building, reducing the impact on landfills.
  • Enjoy improved amenity spaces and improved floor area ratio (FAR).
  • Save energy by reducing indoor temperatures by up to 18°F.
  • Reduce the need for larger HVAC mechanical systems.
  • Extensive green roof systems can reduce cooling needs by 25% and prevent heat loss by 26%.
  • Enjoy local, healthy food sources through urban agriculture.
  • Enjoy a biodiverse ecology with new habitats.
  • Enhance your building’s visual appeal and enjoy delightful aromas.
  • Manage stormwater runoff with growing media that absorbs 70%-80% of rainwater, compared to 20% on standard roofs.
  • Prevent flooding by intercepting the first 5mm of rainfall and retaining (storing) and detaining (delaying the release of) stormwater runoff.
  • Reduce combined sewer overflows (CSOs). A combined sewer system (CSS) collects rainwater runoff, domestic sewage, and industrial wastewater into one pipe, which can often overload the treatment plants.
  • Absorb urban noise pollution for a quieter environment.
  • Pair them with solar panels in a biosolar system to enhance the performance of the panels by up to 15%.
  • Reduce the urban heat island effect and air pollution by up to 20%.
  • May qualify for expedited plan check review and permit issuance, and some cities may also offer fee waivers or reductions.
  • Up to 15 credits can be earned towards a building’s LEED rating based on its design and level of integration with other building systems.

Layers

Vegetation
  • Material: Flora, plants, greening, sedum-mix blanket
  • The layer of plants that cover the green roof and provide the main environmental benefits, such as reducing stormwater runoff, improving air quality, and providing insulation.
Growing Medium
  • Green roll, long rock mineral wool fibers (various mineral mixtures), specially needled to form a compact and stable felt. Soil optimum water retention capacity, light weight, pH of 6.5 – 8.0, lava, pumice, expanded clay, Rockwool
  • The layer of soil or other growing material in which the vegetation is planted. This layer provides the plants with the necessary nutrients and moisture, and also helps to retain stormwater.
Filter
  • Geotextile fabric such as fleece, coco liner, sphagnum moss
  • The layer that separates the growing medium from the drainage layer, preventing fine particles from washing down and clogging the drainage system. This layer resists clogging from fine soil.
Drainage
  • Gravel, dimpled plastic sheets, ribbed fabric laminates
  • The layer that allows excess water to drain away from the growing medium and vegetation, preventing water from pooling and damaging the roof.
Water and Nutrient Reservoirs
  • Recycled non-rotting PP or Polyester fabrics
  • This layer provides additional water and nutrient storage to support plant growth.
Tough Protection Mat
  • HDPE or HDPET, around 500-900 g/m2 in weight
  • This layer provides additional protection for the roof membrane and insulation layers.
Root Barrier
  • HDPE or HDPP, more than 2.5 mm thick
  • The layer that prevents roots from penetrating the roof structure and causing damage.
Waterproofing Membrane
  • Typically made of a synthetic material such as PVC, EPDM, or butyl rubber (IIR)
  • The layer that provides a waterproof barrier to protect the roof structure from water damage and leaks.
Insulation
  • Foam or other insulating material
  • The layer that provides additional thermal insulation to the building, reducing heating and cooling costs.
Structural Support
  • Additional supports or reinforcement
  • The layer that provides the structural support necessary to hold the weight of the green roof and its components. This layer may include additional supports or reinforcement to ensure the roof can safely bear the weight of the vegetation and growing medium.
Note: While the drainage layer and water and nutrient reservoirs layers may serve some similar purposes, they are typically separate layers in a green roof construction. The drainage layer allows excess water to drain away from the growing medium, while the water and nutrient reservoirs layer retains water and nutrients to support plant growth during dry periods. However, some green roofs may use a combined drainage and water retention layer, which serves both functions.

Pricing

Green Roof Types

  • Intensive $100+ to $50 / SF
  • Semi-Intensive $50 – $30 / SF
  • Extensive $30 – $10 / SF
  • Annual Maintenance $0.75 – $1.50 / SF

Traditional Roof Types

  • Tile $7 / SF
  • Asphalt shingle $5 / SF
Discover the advantages of green roofs for your property with our flexible pricing options. Our installation pricing varies based on the size, roof access challenges, brand, warranty, and whether it’s for a residential or commercial building. For sedum and extensive (<4” media) roofs, significant economies of scale exist in larger sizes, making it an affordable investment for your property.

We understand that a green roof investment needs to have a clear ROI. Our experienced team can demonstrate the value of your investment, showcasing the potential monetary and health benefits of a green roof, particularly in high-rise city applications. Additionally, plants are considered a tax-deductible business expense, making it a smart financial decision. Furthermore, installing a green roof can add value to your property. When you sell your property, outdoor improvements like landscaping, installing a sprinkler system, or building a walkway or driveway can adjust your basis, lowering your capital gains tax.

Installation

When it comes to installing soil on a green roof, a boom lift with a super sack can be used as an alternative to blower trucks. Soil quality plays a crucial role in plant growth and is determined by several factors, including texture, structure, organic matter content, pH, and nutrient levels. The ideal soil type varies depending on the plants that are being grown, as different plants have different needs. For example, succulents prefer soils with good drainage and low water retention, while ferns prefer moist soils that retain water.

There are two main types of soil: organic and aggregated. Organic soils contain organic matter, such as decaying plant and animal material, which provides nutrients for plant growth but requires frequent replenishment. Aggregated soils, such as sandy clay soils, contain a higher percentage of mineral particles, including sand, silt, and clay, which give the soil structure and allow for proper drainage. Sandy clay soils have some of the advantages of both sandy and clay soils. They offer better drainage than clay soils while still retaining some moisture due to their clay content. Loam soils generally do not dry out as quickly as sandy soils.

Sedums, a type of low-growing succulent, are an excellent choice for visually appealing green roofs on multi-story buildings. Weeding is typically not necessary for sedums, but removing any weeds or unwanted plants that may compete for water and nutrients is important. Sedums are generally not heavy feeders and can thrive in nutrient-poor soils. However, adding a slow-release fertilizer once or twice a year can help promote healthy growth and flowering.

Tidying plant edges involves trimming back any overgrown or leggy stems, removing dead or damaged foliage, or tidying up the edges of the planting area. The use of L-shaped flashing can help create a clean edge for the sedums. Sedums are drought-tolerant plants that prefer well-draining soils. However, they still require occasional watering during dry periods to prevent the soil from becoming too dry. It’s important to adjust watering frequency based on weather conditions and soil moisture levels.

Case Studies

Urban Strong
  • Location: Brooklyn, NY
  • Premier Project: Javits Convention Center
  • Location of Premier Project: Manhattan, NYC
  • Size of Green Roof (sq ft): 292,000
  • Year Installed: 2018
Recover Green Roofs
  • Location: Somerville, MA
  • Premier Project: Boston Medical Center Rooftop Farm
  • Location of Premier Project: Boston, MA
  • Size of Green Roof (sq ft): 5,000
  • Year Installed: SP 2017
American Hydrotech
  • Location: Chicago, IL
  • Premier Project: California Academy of Sciences
  • Location of Premier Project: San Francisco, CA
  • Size of Green Roof (sq ft): 142,860
  • Year Installed: 2007
Good Earth Plants
  • Location: San Diego, CA
  • Premier Project: FAANG Company Moss Wall
  • Location of Premier Project: Los Angeles, CA
Green Rise Technologies
  • Location: Readyville, TN
  • Premier Project: University of Virginia Hospital
  • Location of Premier Project: Charlottesville, VA
  • Size of Green Roof (sq ft): 191,000
Green roofs are increasingly recognized as an important contributor to community well-being, with Toronto leading the way as the first city in North America to introduce a green roof by-law and boasting the highest rate of adoption. This initiative has allowed Toronto to manage 40% of its stormwater, and other US cities, including Washington DC, New York, Massachusetts, and Chicago, are following suit. San Francisco’s Better Roofs Ordinance mandates that new buildings incorporate either 15% solar panels or 30% green roofs. We aim to establish local ordinances or programs that support the widespread implementation of green roof technology, as green roofs contribute to community well-being at all levels. Furthermore, the Public School Green Rooftop Program (H.R. 1863) provides $500 million in federal funding to support green roof installation and maintenance on K-12 public schools in underserved US neighborhoods. In Europe, Switzerland and Austria have established specific standards and codes of practice for green roofs.

Biosolar

Biosolar roofs represent an innovative technology that combines vegetation with solar panels, creating a mutually beneficial relationship. The plants leverage evapotranspiration to create a cool microclimate that reduces the temperature of the panels by providing shade and evaporative cooling through transpiration. While the condensation that forms on the panels provides moisture for the plants.

Studies have demonstrated that biosolar roofs can boost the efficiency of solar panels by up to 15% under certain conditions. This prevents overheating, which can impair the performance of solar panels. In addition, the plants help to minimize the accumulation of dust and debris on the panels, which can also impact efficiency.

Typically, photovoltaic (PV) systems function optimally at temperatures below 90°F. However, temperatures exceeding 110°F can result in a 10%-25% reduction in solar power output. To optimize the performance of solar panels, they can be equipped with low-power fans for cooling via forced convection or manufactured with non-reflective white cells. These measures can significantly enhance efficiency and output.