General Specification for Building 2017 Edition

1 General Specification for Building 2017 Edition The 2017 Edition of the General Specification for Building has incorporated updates and revisions to the 2012 Edition (incorporating Corrigendum No. GS 2012-02). Principle amendments and additions include a General review of the technical requirements, updating the international standards (such as ASTM, BS and BS EN etc.) as well as incorporation of further green specifications to be in line with the Government s green procurement policy. Please refer to the summary of major changes for details. The updating of Specification is a continuous process. The electronic version of this 2017 Edition of the General Specification for Building will be kept up-to-date and may be viewed on the ArchSD Internet homepage.

2 In view of the revisions and new additions, there will be an introductory period of about 3 months in preparation for full implementation of this 2017 Edition as contract document starting from 1 October 2017 . In summary: For tenders to be invited on or after 1 October 2017 , this 2017 Edition shall be used. Existing contracts (including contracts using previous editions tendered before 1 October 2017 ) will not be affected. ARCHITECTURAL SERVICES DEPARTMENT General Specification FOR Building 2017 Edition The follow clauses and indexes are amended in the above Edition of General Specification for Building . Amendments to Section 1 Abbreviations Abbreviations used shall have the following meanings.

3 BS British Standard BS EN European Standard CP Code of Practice CS Construction Standard GS General Specification for Building IEC International Electrotechnical Commission ISO International Organization for Standardization Publication PS Particular Specification PW Public Works SO Supervising Officer DEVB List Development Bureau current enforced List of Approved Suppliers of Materials and Specialist Contractors for Public Works. Proprietary brand name products or materials The phrase or alternative products or materials having equivalent functions or performance shall be deemed to be included wherever products or materials are specified by proprietary brand names.

4 Alternative products or materials of different brands or manufacture having equivalent functions or performance may substitute for the specified proprietary brand name products or materials if prior approval from the SO has been obtained. If the Contractor intends to use the intellectual property rights of another party in performing his obligations under the Contract, appropriate licences shall be obtained from the relevant rights owners. Equivalent standards and imperial sizes When products or materials to the appropriate standards are not available, products or materials conforming with equivalent standards (or performance) shall be acceptable subject to approval. When a material is available in metric size, an imperial size equivalent shall not be acceptable.

5 If a material is unobtainable in metric size, a material of the nearest equivalent imperial size which will fully meet the Specification may be substituted if prior approval has been obtained, but the rates will not be changed from those submitted for the materials specified. Trees and shrubs Provide a record of existing trees, if any, within and in close vicinity (within 2000 mm) of the site boundary and works areas. (A plant is considered as a tree if its trunk diameter measures 95 mm or more at a height of 1300 mm above the ground level. (Guidance on measurement of tree diameter is given in Agriculture, Fisheries and Conservation Department s Nature Conservation Practice Note )) Photographic record and location plan for individual tree together with the Tree Schedule shall be submitted within 28 days after commencement of the Works or nomination by the SO.

6 The Tree Schedule shall show the following particulars: (a) A number identity for each tree, also marked on each photograph; (b) The species (scientific names and Chinese common names); (c) Trunk diameter (at 1300mm above the ground level); (d) Tree crown spread; (e) Overall height; (e) Condition of the tree; (g) Existing ground level at the root collar. Protect and preserve all existing trees and shrubs on Site. No physical disturbance including transplanting/felling/pruning of any existing tree shall be permitted without prior written consent of the SO and the statutory approval. Take precaution and provide all necessary on-site protection works/measures (including tree surgery works if so required) for individual existing tree, if any, within or in close vicinity (within 2000 mm) of the site boundary and/or works area throughout the Contract period.

7 Temporary fencing, if necessary shall be provided to prevent the encroachment of equipment or materials and contamination of the surrounding ground by oil or other deleterious substances. Do not bank spoil, vegetable soil or other materials within the drip-line zone of individual trees. If it is necessary to trim or cut back trees and shrubs, it must be done under the direction and supervision of the SO in strict compliance with Clauses to and Section 25 of the GS. Make allowance in method of operation and vehicular access for tree preservation during the period of Works. Submissions (i) The Contractor shall submit for the consent of the SO the following information in accordance with the CPFBSS and CPFMSS and Guidelines on the Design and Construction of Bamboo Scaffolds, issued by the Buildings Department, taking into account site and project conditions 10 days prior to commencing the erection, alteration or dismantling of the Scaffold System: (a) The material specifications, test certificates, place of the origin, and instructions and procedures supplied by the manufacturers of the metal Scaffold System.

8 (b) The intended or current use of the Scaffold System and a method statement for the erection, alteration or dismantling of the same. Working drawings for the Scaffold System as per Clause of this Section shall be submitted with the method statement; (c) For any portion of the Scaffold System which cantilevers up from the top floor under construction, the method statement shall include adequate tie and strut arrangement for the cantilevered portion; (d) The names, substantial training and practical experience of the competent person , the trained workmen and the professional engineer as referred to in CPFBSS and CPFMSS. (ii) The consent of the SO shall not relieve the Contractor of any duty or responsibility under the Contract.

9 Construction (i) The Scaffold System shall be constructed and maintained in accordance with the following criteria: (a) Provide firm and adequate supports to the Scaffold System at appropriate locations. If steel brackets are used as scaffold supports, their vertical spacing shall not exceed 15 m; (b) Provide firm and adequate ties and struts for fastening the Scaffold System securely onto the structure or Building . All temporary ties, fixing bolts and the like shall not be allowed to remain within the specified concrete cover and shall be cut back more than 40 mm (concrete cover for external elements) from the surface of structural concrete; (c) Provide firm and adequate longitudinal, transverse and diagonal bracings to ensure the stability of the Scaffold System; (d) Keep the space or clearance between working platforms and the structure or Building as small as possible but it shall not exceed 300 mm wide.

10 (e) Where scaffolding is provided for structure or Building exceeding 15 m in height, provide a protective canopy of nominal width 3600 mm at a maximum height of 6 m above ground along the edges of the structure or Building at locations as directed by the SO; (f) Where scaffolding is provided for structure or Building which is under 30 m in height or is set back from the site boundary such that an inclined projection plane from the top outer edge of the structure or Building at 10 degree from the vertical does not go beyond the site boundary at ground level, provide safety nets comprising nylon mesh of minimum 15 core threads with grids not more than 12 mm or of similar approved type covering the entire face of the structure or Building .