What is the cost of a green roof?
The cost of a green roof differs in a number of factors such as the types of system (intensive, extensive or hybrid), the type of growing media, complexity of installation etc. Our proposed green roof system is easily affordable for the public. The exact cost depends on the extend of greening effect aimed. For our proposed modular tray system, the cost is around HKD$ per square foot. It should be noted that a well-established green roof can cut down a favorable sum on maintenance by extending the life span of a roof.
Is it feasible to put a green roof on an existing building?
Yes. Under the usual procedure, the subject building shall first pass the loading and water-proofing assessments conducted by a structural engineer. This is to ensure the bearing capacity is favorable to the installation of a green roof and avoid leakage after installation, which either case may constitutes structural problems if neglected. Moreover, aged buildings are recommended to acquire more special cares because of the prolonged wearing out.
What is the difference between a modular tray system and an intensive system?
One of the major differences between a modular system and a traditional built up system is the growing media. For a modular system, the growing media is specially mixed and selected lightweight materials. However, it composed of the same essential elements as soil such as mineral components and organic matter. Another crucial difference is the depth of growing media. A modular system is designed for low lying plants while an intensive system is intended to stimulate a natural landscape. This eventually affects the types of plant cultivated. Other differences are the installation cost, maintenance cost, landscape etc.
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Do we have a sloped green roof?
Yes, there are different products available to suit every consumer needs. As long as the loading capacity and the waterproofing of your roof qualify, a green roof can be installed. However, it should be noted that the installation cost increase with the slope of a roof. Moreover, extra cost may be incurred for roof with 30 degree inclination or above.
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Can we grow food on the green roof?
It depends on the adopted systems. Normally, tradition crops such as vegetables and fruits need deep and nutritious soil. Moreover, frequent irrigation and maintenance are essential for the plant growth. Therefore, it is not recommended to grow food in an extensive modular system.
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Frequently Asked Questions
Some of the frequently asked questions are listed below. If you have any further enquiries, please do not hesitate to email us at greenroof_toppers@gmail.com and we will reply you promptly.
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Is it necessary to water my green roof?
For the majority technologies available on the market, most of them require watering. However, it depends on the weather and the type of plants cultivated. For example, irrigation is not necessary in rainy season. Besides, tough, drought tolerant Sedum are able to self-sustain in drought seasons.
Can we walk on the green roof?
Normally, extensive green roof system and modular green roof system are not built for pedestrian traffic. It is recommended that people should bypass the plantation. However, an occasion passing by inspectors due to maintenance would not seriously damage the green roof for most plants.
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The provision of public and private open space in Hong Kong is regulated in accordance with the Hong Kong Planning Standards and Guidelines (HKPSG), town plans gazetted under the Town Planning Ordinance (TPO) and private lot Lease Conditions. Frequently, both Government and the private sector achieve the required open space provision through the creation of intensive green roofs at podium level.