Sky Woodland for Urban Power Transmission Substation in Hong Kong

Abstract

CLP Power Hong Kong Limited generates and supplies reliable electricity to over 2.2 million customers in its supply area. It owns about 210 transmission substation buildings. Many green initiatives have been incorporated into recently built substations. This paper introduces a green building initiative Sky Woodland, at Sham Mong Road Substation on a building of 7 m tall for completion in mid 2008. This pioneering pilot project contributes both environmental and scientific research value, aiming at exploring the viability and effectiveness of creating an intensive green roof on the top of a substation building. Native tree species have been chosen for tree form, foliage, seasonal colours and attractive flowers. They will be planted closely to establish a crown interlocking effect and to emulate a natural woodland. Sapling or standard trees of about 2 ~ 4 m in height will be planted to reach a medium final height of 8 ~ 10 m. Specially designed drainage, water storage and soil layers will provide a suitable substrate to support woodland growth. Environmental monitoring will be conducted to evaluate the wide range of benefits to both the public and the company, such as pleasant green landscape for the site and surrounding residents, reduction of air and indoor temperature, improvement of air quality, and extending the life span of the building roof. The challenges of the project include tree selection against occasional typhoon damage, landscape design, tree transplanting and establishment, building load bearing capacity, and protection and the separation of building provisions. The valuable experience could facilitate future green roof installation of the company and other local developments.