One of the major disadvantages of curtain walls is the need for regular maintenance. In order to keep out moisture and wind, a sealant must be applied to the perimeter, and this sealant must be replaced every 10 years or so. Another major disadvantage of curtain walls is the cost and time required to install them. Curtain walls utilizing the stick system, for example, require a great deal of time to assemble, and their performance depends on the quality of the installation. Unitized curtain walls consist of factory-assembled frames which reduces installation time and cost but incurs greater costs for shipping and storage.
Advantages
Before steel and reinforced concrete became common building materials, a building's facade typically supported …show more content…
Under regulation 42 of the Building (Construction) Regulations (B(C)R), curtain wall means a non load-bearing enclosure fixed onto the load-bearing structure with its dead loads, imposed loads and wind loads transferred to the structure through fixings. Where a curtain wall system (including other similar non load-bearing enclosure system) forms the external face of a building, the BA is prepared to accept the outer face of the structural elements, e.g. beams, columns and floor slabs, as the external wall for the purpose of measurement of GFA and site coverage (SC) where (a) The curtain wall system itself does not form part of the structural system of the parent building; (b) The system does not result in any additional floor area at a floor level by providing a reinforced concrete dwarf perimeter wall not less than 300 mm high measured from the floor level; (c) The projection of the system from the outer face of the structural elements does not exceed 200 mm for a domestic building and 250 mm for a non-domestic building; and (d) The external reflectance2 of the …show more content…
The method of measurement of GFA and SC is illustrated in the sketches at Appendix B for reference. The requirements stipulated in item (d) above are applicable to all new building plans or major revision of building plans for development proposals or alteration and addition works submitted to the BA for approval on or after 1 September 2015. For the avoidance of doubt, a purpose built hotel building including the hotel part of a building or a hotel converted from a non-domestic building is treated as a non-domestic building or non-domestic part of a building for the purpose of item (c) above. 7. For the provision of curtain walls to existing facades in the case of wholesale conversion or refurbishment of industrial buildings or other types of buildings, exemption from section 31 (1) of the Buildings Ordinance (BO) to allow the curtain walls to project over streets will be favourably considered if low-energy absorbent type glazing / energy efficient materials with energy efficient design of the curtain walls that could achieve 40% in the categories of Energy Use (EU) and Indoor Environmental Quality (IEQ) with the BEAM Plus Certification conferred by the Hong Kong Green Building Council (HKGBC) are incorporated in the proposal. As the pre-requisites for the granting of the exemption, the applicant in applying for approval of plans should submit the official letter issued by the HKGBC acknowledging the satisfactory completion of project registration
Advantages
Before steel and reinforced concrete became common building materials, a building's facade typically supported …show more content…
Under regulation 42 of the Building (Construction) Regulations (B(C)R), curtain wall means a non load-bearing enclosure fixed onto the load-bearing structure with its dead loads, imposed loads and wind loads transferred to the structure through fixings. Where a curtain wall system (including other similar non load-bearing enclosure system) forms the external face of a building, the BA is prepared to accept the outer face of the structural elements, e.g. beams, columns and floor slabs, as the external wall for the purpose of measurement of GFA and site coverage (SC) where (a) The curtain wall system itself does not form part of the structural system of the parent building; (b) The system does not result in any additional floor area at a floor level by providing a reinforced concrete dwarf perimeter wall not less than 300 mm high measured from the floor level; (c) The projection of the system from the outer face of the structural elements does not exceed 200 mm for a domestic building and 250 mm for a non-domestic building; and (d) The external reflectance2 of the …show more content…
The method of measurement of GFA and SC is illustrated in the sketches at Appendix B for reference. The requirements stipulated in item (d) above are applicable to all new building plans or major revision of building plans for development proposals or alteration and addition works submitted to the BA for approval on or after 1 September 2015. For the avoidance of doubt, a purpose built hotel building including the hotel part of a building or a hotel converted from a non-domestic building is treated as a non-domestic building or non-domestic part of a building for the purpose of item (c) above. 7. For the provision of curtain walls to existing facades in the case of wholesale conversion or refurbishment of industrial buildings or other types of buildings, exemption from section 31 (1) of the Buildings Ordinance (BO) to allow the curtain walls to project over streets will be favourably considered if low-energy absorbent type glazing / energy efficient materials with energy efficient design of the curtain walls that could achieve 40% in the categories of Energy Use (EU) and Indoor Environmental Quality (IEQ) with the BEAM Plus Certification conferred by the Hong Kong Green Building Council (HKGBC) are incorporated in the proposal. As the pre-requisites for the granting of the exemption, the applicant in applying for approval of plans should submit the official letter issued by the HKGBC acknowledging the satisfactory completion of project registration