Insulates buildings, therefore conserving energy.

Improve air quality and reduce CO2 emissions.

Absorb and retain rain fall, reducing and delaying stormwater system load.

Reduce ‘urban heat island effect,’ where solar energy is re-radiated off buildings, heating the surroundings.

Increase access to private outdoor green space within the urbanenvironment, at home or at work.

Promote individual, community, and cultural diversity.

Any roof surface can be greened - even sloped or curved roofs can support a layer of sod or wildflowers.

Water proof membrane is fundamental basis of all roof top gardens. To limit leakage problems:

Compartmentalise planting beds, or use moveable containers.

Protect membrane from shovels, heels etc with a pebble drainage layer, and use raised walkways.

Keep garden free draining. Include filters and drain covers in this system.

Keep compost in own container for turning, aeration and leachate collection.

Legislation for urban green roof tops is appearing globally.

Rooftop gardening is fashionable! A new category in the Chealsea Flower Show illustrates the growing popularity.

Low growing, droughttolerant systems can require no maintenance.

Improve urban aesthetics

Increase the value of buildings for owners and tenants.

Create job opportunities in the fields of research, design, construction, landscaping, gardening, health, and food production .

Use unused space for productive purposes.

Rising populations rely on shrinkingfarmlands.

Increase habitat for birds.

Support urban food production.

Give a little something back to the world!

Reconnect with thecycles that support our lives.

Consider all Factors Analysis 1

Consider all Factors Analysis 2

Access can be a problem for set up. All soil etc may need to be brought up to the roof in bags, using stairs or the elevator.

If a building is to be retrofittedwith a green roof, a structural engineermust be consulted.

Odours from sewer vent pressure pipes and grease vent pipes on roofs require scrubbers to be fitted.

Composting could bring about smell or vermin if practised poorly.

Warning:gardening may be addictive.

Where rooftop gardens have not yet been officially recognised in building codes, the safety of such projects is left to the discretion of individual building inspectors.

Terra-cotta containers usually crack in hard frost conditions.

Plant selection is often restricted by arid and exposed roof top environment.

www:.cityfarmer.org.rooftopgarden.com.egov.cityofchicago.org.asla.org/greenroofeducation.thegreenroofcentre.co.uk.bonnieplants.com.lifecyclesproject.ca

Hydroponic systems, and highly modified eco systems, may become more dependant on chemical inputs.

Initial installation costs can be high.

Depending on greenroof type, maintenance can be just as great as a normal garden.

Ownership issues may arise between tenants and building owners.

Container gardening is adifferent experience from traditional gardening, and new skills will have to be learned.

Lack of information and expertise.

Shallow beds or pots require con-sistent and regular irrigation; at least once par day in summer.

Gardeners in high-rises have great intentions to water once a day, but they don’t! Drip irrigation may be required.

More extreme growing environment, especially sun and drying

Use and productivity may be highly seasonal.

Limited availability and selection in some city areas for soils, composts, plants.