THE HONG KONG HOUSING AUTHORITY. Memorandum for the Building Committee

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1 BC 13/99 THE HONG KONG HOUSING AUTHORITY Memorandum for the Building Committee Proposed Master Layout Plan, Scheme Design and Development Cost Budget for Development of Aldrich Bay Phase 4 and Neighbourhood Community Centre Site PURPOSE To seek Members approval to the proposed Master Layout Plan, Scheme Design and Development Cost Budget for Development of Aldrich Bay Phase 4 and Neighbourhood Community Centre (NCC) Site. BACKGROUND 2. The Aldrich Bay reclamation area is located at the Eastern District of Hong Kong Island. It is bounded to the west by the Sai Wan Ho reclamation and to the east by Shaukeiwan and A Kung Ngam. The Aldrich Bay Phase 4 and NCC Site is an extension to three other committed phases of public housing development at the Aldrich Bay reclamation area. (see Part I of Annex). 3. Past events relevant to this project are as follows - Date Event (a) 24 July 1996 Planning Brief of Aldrich Bay Phases 1 to 3 was approved by the Committee on Planning and Land Development (CPLD).

2 - 2 - (b) 18 December 1997 Proposed Revised Planning Brief incorporating Phase 4 into the development was endorsed by the department s Project Design Review Committee (PDRC). (c) 19 March 1998 The development parameters, conceptual layout, development programme and project estimate approved by PDRC (PDRC Paper No. 10/98 refers). (d) 28 May 1998 Inclusion of the project in the Public Housing Development Programme (PHDP) following submission to Strategic Planning Committee (SPC) (Paper No. SPC 24/98 refers). (e) 24 September 1998 Proposed Master Layout Plan, Scheme Design and Project Budget endorsed by PDRC (PDRC Paper No. 42/98 refers). (f) 19 November 1998 Resubmission of proposed Master Layout Plan, Scheme Design and Project Budget endorsed by PDRC. INTERDEPARTMENTAL CIRCULATION 4. Further development on the sketch design annexed to Paper No. SPC 24/98 was made in liaison with concerned departments such as Education Department, Social Welfare Department, Transport Department, Drainage Services Department, Home Affairs Department, and Fire Services Department between May 1998 to December 1998.

3 Comments received on major items are summarized as follows - Department Comments Design Team s Response Director of Education (ED) Chief Engineer/ HK&I Drainage Services Department (DSD) Director of Home Affairs (HAD) Director of Environmental Protection (EPD) A 24-classroom primary school with a site area of 4,100m² is required. Minimum headroom of 5.1m to be provided along the Drainage Reserve with two desilting openings and works areas for regular maintenance and inspection by DSD. A Community Hall is to be incorporated as part of the NCC complex to maximise site utilisation. Maximum possible setback of the residential blocks and school from the Island Eastern Corridor (IEC) with selfprotecting housing blocks as noise barriers. A new Arch SD 2000 Design for 24-classroom primary school with separate Emergency Vehicular Access (EVA) from the estate is provided. To suit the proposed EVA layout, HD proposes to relocate one of the desilting openings and add one inspection manhole to fulfill DSD s requirement. The NCC and Welfare Complex has incorporated the required Community Hall. Setback of 30m from the IEC and 10m from Road 9/1 is provided. In addition, Single Aspect Concord Blocks (SACB) are provided, which act as noise barrier for the other affected buildings.

4 - 4 - Department Comments Design Team s Response Director of Fire Services (FSD) With reference to the Scheme Design and Master Layout Plan endorsed by PDRC in September 1998, FSD commented that EVA should be provided on top of the carpark podium to serve the SACBs. Subsequent discussion with FSD clarified that the above provision was required because the major facade of the SACBs were not accessible for fire services ladder operation due to the excessive height of the the carpark podium and the lowest domestic floor. The recommended height of podium and lowest domestic floor from the EVA is 15m and 20m respectively. The feasibility of providing EVA through the carparking floors leading to the top of the carpark podium was studied and found uneconomical due to higher floor to floor height and heavier floor loading to accommodate the fire appliance required. A more economical solution is now proposed by relocating the carpark podium to the eastern side of the site. The relocation has the advantage of avoiding the carpark to deck over the 12m wide drainage reserve which required 5.1m clear headroom and deep structural beam to deck over. In the revised carpark layout, height of the lowest domestic floor above the carpark podium is 20m from the EVA as recommended.

5 - 5 - REVISED DEVELOPMENT PARAMETER 6. The approved Development Parameters need to be amended based on the proposed Master Layout Plan and Scheme Design as follows - Net Site Area Development Ratio Plot Ratio Number of Flats Private Carparks Open Space Revised Development Parameter Approved Development Parameter 12,450m²* 8.72** ,630*** 251 4,887m² 13,700m² , ,931m² * Net Site Area is reduced due to increase in road area and school site area in the proposed Master Layout Plan. ** Development Ratio is increased mainly due to reduction in Net Site Area. *** Number of flats are reduced due to one rental domestic floor in Block 5 (SHD/NCC Complex) is used to accommodate supporting facilities required by the Residential Care Home for the Elderly, and loss of 16 HOS flats due to relocation of the carpark podium. MASTER LAYOUT PLAN AND SCHEME DESIGN PROPOSAL 7. The proposed Master Layout Plan and Scheme Design generally complies both with the Approved Development Parameters and the Conceptual Layout and comprises - (a) (b) One 37-storey Single Aspect Concord Block and one 37-storey New Cruciform Block on a 4-storey carpark podium. One 41-storey New Cruciform Block and one 41-storey Single Aspect Concord Block.

6 - 6 - (c) (d) (e) A 21-storey NCC and Welfare Complex containing the Small Household Units, Community Hall, Social Centre for the Elderly and a Residential Care Home for the Elderly. The construction of the Community Hall, Residential Care Home and Social Centre for the Elderly are to be funded by other departments as per the agreed arrangement for NCC Sites. A 24-classroom Primary School adopting the new Arch SD 2000 Design. Associated external works. 8. Explanatory notes and drawings are attached at Part I of Annex. The main features of the proposed Scheme Design are - (a) (b) (c) (d) (e) The Single Aspect Concord Blocks and the carpark podium fronting Road 9/1 will serve as noise barrier; a linear building form for the Small Household Block with the NCC and Welfare Complex is proposed for the narrow site; an estate road built on part of the 12m drainage reserve (a non-building area) provides the main circulation spine and EVA to the HOS blocks and the NCC and Welfare Complex; a covered walkway system incorporating light structures and building canopies to link the Phase 4 blocks together with connection to other neighbouring phases; and due to site constraint and a 12m wide drainage reserve running across the site, Automatic Refuse Collection System (ARCS) will not be provided.

7 - 7 - OVERALL DEVELOPMENT 9. The approved Overall Development as compared with the Overall Development provided in Aldrich Bay Phases 1 to 4 and NCC Site are as follows - Flat Number Design Population (Persons) Approved Provided Approved Provided Rental HOS Rental HOS Phase 1 2,537-7,764 Phase 2 3,050 2,750-1,600 18,090 5,215 Phase Phase ,216 4,909 Total 3,050 2,750 3,207 2,816 18,090 18,368 5,800 6,023 (+3.8%) (+1.5%) The total Flat Number provided is within the + 10% deviation allowed in the Planning Brief.

8 - 8 - DEVELOPMENT COST BUDGET 10. The Proposed Development Cost Budget is estimated to be $1, M. The breakdown of the budget calculations is given in Part II of Annex and the key elements are as follows - Development Cost Budget ($M) (a) Piling/Building 1, (b) Soft Landscape and Others (c) Project Management Cost (d) Other Project Cost (e) Development Contingency Total 1, The Breakdown of Proposed Development Cost Budget is as follows - (A) Proposed Development Cost Budget ($M) (a) Site Development Cost 1. Site Formation - 2. Demolition - Sub-total - (b) Construction Cost 3. Foundation Building Soft Landscape and Others Sub-total 1, (c) Project Management Cost 6. Professional Services & Overheads 7. Consultant Fees Consultant Site Staff (a + b) x 16% Sub-total (d) Other Project Cost 9. Ancillary Project Expenses 10. Miscellaneous Cost (a + b) x 3% Sub-total (e) Development Contingency 11. Risk Provision 12. Allowable Variance (a + b + c + d) x 10% Sub-total Total Development Cost Budget : 1, (a) + (b) + (c) + (d) + (e)

9 The unit cost of the proposed Development Cost Budget as compared with SPC s Approved Unit Development Cost Ceiling and the Overall Unit Cost of Construction compared with June 1998 Cost Yardsticks for the whole development are as follows - (a) #Unit Cost of Proposed Development Cost Budget (b) #SPC s Approved Unit Development Cost Ceiling* (Paper No. SPC24/98) (c) Overall Unit Cost of Construction Included in (a) (Excluding external works and others) (d) June 1998 Cost Yardsicks Adjusted to Tender-In-Date Domestic Rental $11,703/m² $12,636/m² $9,235/m² $6,888/m² HOS - NCB $10,142/m² $10,230/m² $7,983/m² $7,226/m² - SACB $12,690/m² $13,437/m² $10,124/m² - Private Car Parking $7,760/m² $7,763/m² $5,981/m² $4,302/m² Light Goods - $8,500/m² - $6,639/m² Vehicle Parking** Average $10,949/m² $11,287/m² $8,652/m² $6,882/m² # Contingency excluded. * Approved Unit Development Cost Ceilings are adjusted to the revised programme. ** Light Goods Vehicle Parking is proposed in the external area. The proposed Unit Development Cost Budget is within SPC s Approved Unit Development Cost Ceiling (adjusted to the revised programme) and the major variation are attributable to the followings - (a) (b) Saving in Domestic Rental Portion due to change in modular flat types. Saving in HOS-SACB due to reduction on unit cost basing on recently return tender price information.

10 The difference between the Overall Unit Cost of Construction (excluding External Works and Others) and the June 1998 Cost Yardsticks Adjusted to Tender-in Date are attributable to the followings - (a) (b) (c) Domestic Rental ($2,347/m² GFA or approx. 34%) HOS-NCB ($938/m² GFA or approx. 13%) Private Car Parking ($1,679/m² GFA or approx. 39%) Higher foundation and building costs due to reclaimed site and nonstandard block design with transfer structure. Higher foundation and building costs due to reclaimed site and integration with carpark podium by transfer structure. Higher foundation and building costs due to reclaimed site and integration with domestic blocks by transfer structure. 13. The proposed Development Cost Budget is also compared with the total Development Cost Estimate submitted to SPC and details are shown in Part II of Annex. 14. The latest development cost for the project will not have a significant impact on financial viability as endorsed by Paper No. SPC 24/98. AVAILABILITY OF FUNDS 15. The estimated yearly expenditure of the Proposed Budget are shown below and would be included in the next capital budget updating of the Authority - Estimated Expenditure ($M) 1998/ /00 Post Total , ,

11 DEVELOPMENT PROGRAMME 16. Details of the development programme are in Part IV of Annex. The key dates are as follows - (a) Scheme Design and Development Cost Budget Endorsement by PDRC 09/98 11/98 (Resubmission) Approval by BC 01/99 (b) Detailed Design Approval by DDRP 05/99 (c) Piling Commencement Completion (d) Building Commencement Completion 07/99 04/00 04/00 GMB Stand 12/00* Primary School 05/02 Blocks 1, 4 and 5 08/02 Blocks 2 and 3 10/02** * Early completion of GMB stand to tie in with completion of Aldrich Bay Phases 1, 2 and 3. ** 30 months of construction period is required for the SACB and the NCB on the four storey carpark podium. RECOMMENDATION 17. The proposed Master Layout Plan, Scheme Design and Development Cost Budget of $1, M for Development of Aldrich Bay Phase 4 and NCC Site as described above and in the Annex to this Paper be approved.

12 DISCUSSION 18. At the next meeting of the Building Committee to be held on 21 January 1999, Members will be invited to approve the recommendation in paragraph 17 above File Ref. : HD(AR) 7/643/4 Date : 15 January 1999

13 B. Summary of Proposed Development Cost Budget Domestic HOS HOS Rental HOS Carparks Unallocable Welfare Total NCB SACB Gross Floor Area 19,390m² 51,754m² 38,533m² 12,537m² 135m² 50m² 122,399m² Development Costs ($M) ($M) ($M) ($M) ($M) ($M) ($M) (a) Site Development Cost Demolition Site Formation Sub-total (b) Construction Cost Foundation (1) Building (2) Soft Landscape & Others (c) Project Management Cost Professional Services & Overheads (3) Consultant Fees (4) Consultant Site Staff (d) Other Project Cost Sub-total , Sub-total (a+b)x16% (a+b)x3% (e) Development Contingency (f) Total Development Cost Budget (g) Unit Development Cost $ /m² GFA (h) SPC Approved Unit Development Cost Ceiling $ /m² GFA (5) , ,874 11,156 13,959 8,536 11,178 11,180 12,042 13,899 11,253 14,781 8, ,415 Notes : (1) Foundation including pile caps. (2) Building cost including Building Services and External Works. (3) A balancing figure to top up the total project management cost to 16%. (4) Consultant Fee including fee for QS consultancy services. (5) The SPC Approved Unit Development Cost Ceiling have been adjusted to the revised programme.

14 B. Summary of proposed Development Cost Budget The Total Development Cost Budget (f) are compared with the total Development Cost Estimate submitted to SPC as follows - Total Development Cost Budget Total Development Cost Estimate to SPC * Domestic HOS HOS Rental HOS Carparks Unallocable Welfare Total NCB SACB ($M) ($M) ($M) ($M) ($M) ($M) ($M) , , Variance Amount Variance % % -3.57% +3.24% -6.91% * Note : The total Development Cost Estimate to SPC have been adjusted due to the revised programme. The major reasons for the variances are : (a) (b) (c) (d) Saving in Domestic Rental Portion due to reduction in the number of flats and change of modular flat types. Saving in HOS-NCB due to reduction in the number of flats. Addition to HOS-SACB due to increase in the number of flats. Saving in Carparks due to increase in efficiency ratio of carparking space. C. Summary of Cost Per Flat for Domestic Block Block Type Flat Type Flat Size (m² GFA) No. of Flats Domestic Rental 1P/2P - 35% 2P - 42% 1B - 8% 2B - 15% HOS-NCB 2B - 40% 3B - 60% HOS-SACB 2B - 67% 3B - 33% Construction Cost Per Flat ($) Development Cost Per Flat ($) 46.84m² GFA ave , , m² GFA ave , , m² GFA ave ,149 1,179,605

15 CONTENTS PART I MASTER LAYOUT AND SCHEME DESIGN A. Introduction A.1 Location Plan A.2 Site Description A.3 Background B. Evaluation of Master Layout and Scheme Design B.1 Site Opportunities and Constraints B.2 Built Form B.3 Pedestrian and Vehicle Circulation B.4 Open Space Structure B.5 Programme and Implementation C. Master Layout and Scheme Design Drawings Appendices Appendix I - Schedule of Accommodation Appendix II - Summary of Comments on Inter-departmental Circulation PART II DEVELOPMENT COST BUDGET A. Summary and Calculation of Project Estimate. B. Summary of Proposed Development Cost Budget. C. Summary of Cost Per Flat for Domestic Block. PART III DEVELOPMENT PROGRAMME ISSUE 1

16 AMENDMENT RECORD SHEET ISSUE 1

17 PART I MASTER LAYOUT AND SCHEME DESIGN A. Introduction A.1 Location Plan ISSUE 1 PAGE 1

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19 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) A.2 Site Description (1) Land Status of the Site Optimise development potential of the site with regards to circulation, environmental protection, urban design and landscape requirements. (2) Site Area The site occupies a gross area of approximately 1.95 hectares. The net site area is 1.37 hectares. (Net site area excludes GMB stand, school, estate road but includes the NCC site) The site is zoned esidential (Group A) [R(A)] on the Outline Zoning Plan. Ensure a comprehensive and balanced provision of open space, community and commercial facilities for the development. The design criteria have been incorporated in the proposed Master Layout Plan and Scheme Design. The gross site area is verified as 1.95 hectares. The net site area is verified as hectares, due to increase in road area and school site area in the proposed Master Layout Plan. (Net site area excludes GMB stand, primary school, estate road but includes the NCC site.) ISSUE 1 PAGE 3

20 (3) Air Height Restriction (AHR) The site is governed by the Airport Height Restriction (AHR) prescribed under the Hong Kong Airport (control of Obstruction) (No. 2) Order Following relocation of Kai Tak Airport to Chek Lap Kok the AHR is revised to +400mPD. The maximum proposed building height of mPD is within the AHR limit. ISSUE 1 PAGE 4

21 PART I MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUTAND SCHEME DESIGN (4) Surrounding Land Use On the east are Phases 1, 2 and 3 of Aldrich Bay Development. On the other three sides are Roads 9/1, 9/2 and 9/3 under construction by Highways Department. Adjacent land use includes a waterfront promenade to the North, the Eastern Island Corridor and a tram depot to the South. Construction of new roadworks by Highways Department will facilitate future utility connections in coordination with the programme. Completion of the new roadworks is scheduled for end of year 2000 which ties in with the Phase 4 building construction programme. (5) Site Topography The site is formed generally to level +4.0 PD. The site consists of recently reclaimed land susceptible to ground settlement. The land fill with public dumping material is mainly building debris and boulders. A formed level of +4.60mPD is proposed to allow sufficient cover for drainage pipes. The site will gradually slope from +4.60mPD to +4.10mPD at the southern end of the site. The foundation design, building design and landscape design will take in account the reclaimed land conditions. Future maintenance of external works will take in account ground settlement which may occur. ISSUE 1 PAGE 5

22 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) (6) Site Access Vehicular access and pedestrian access into the site will be through the entrance off Road 9/1. The minibuses stopping at the GMB stand will faciliate access into the site from the northern end. (7) Utility Services Revised ingress/egress points into the site have been agreed with Drainage Services Department (DSD), Transport Department (TD) and Highways Department (Hwy D). Vehicular access and emergency access into the site will be through the entrance off Road 9/1. The main pedestrian flow will be along the footpath of Road 9/1 accessible from Shaukeiwan MTR, and the neighbouring Phases 1-3 where the Commercial Shopping Centre is located. There is a bus stop along Road 9/2 from the west, also a Green Minibus Stand (GMB) at the corner between Roads 9/2 and 9/3 which will facilitate pedestrian access into the site from the north. (a) Water Supply New water supply mains will be laid in the Aldrich Bay reclamation area by WSD in conjunction with Highways Department. WSD will lay new fresh and salt water mains in conjunction with Highways Department roadworks, to complete by November Provision of water supply will meet the programme requirement of the project. ISSUE 1 PAGE 6

23 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) (b) Drainage There is a 12m wide drainage reserve crossing the site. It provides the main discharge for storm water drainage in the Shaukeiwan area. A minimum headroom of 5.1m is required along the reserve. Requirements by DSD :- - minimum headroom of 5.1m over the drainage reserve. - 8m x 10m works area around desilting opening to be occupied by DSD plants during maintenance hr. unobstructed vehicular access to desilting opening. An additional inspection manhole to be provided between the 2 desilting openings within the site. - Relocation and construction of one of the desilting opening near Road 9/1 to be carried out and funded by the Housing Department. - No permanent structural loading shall be inserted on the existing box culvert in the drainage reserve. - Arrangement of sewerage connection to public sewer to be approved by DSD. Requirements of DSD are incorporated in the Scheme Design. Traffic and pedestrian circulation in the estate will not be interrupted when DSD works areas are occupied for inspection and maintenance at the desilting opening. Relocation of desilting opening near Road 9/1 has been agreed with DSD to avoid obstruction to the road access. The relocation works will be carried out with cost borne by the Housing Department. Liaison with DSD is underway for sewerage connection of existing public trunk sewer at Road 9/1. (c) Electricity, Telephone and Gas New mains cables will be laid by the various utility companies in conjunction with Highways Department. Programme for laying of cables to tie in with the roadworks construction. The utility services for the Rental Estate and the HOS courts as well as the Primary School will be separated for the purpose of management and maintenance. ISSUE 1 PAGE 7

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25 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) (d) Diversion of Existing Services No diversion of existing underground services within the site is required. A.3 Background (1) Public Housing Development The reclamation site was formed in 1994/5 by CE/Port Works of Civil Engineering Department. The site is situated at Aldrich Bay on land reclaimed for public housing development. It is an extension to Phases 1, 2 & 3 of the Aldrich Bay Development. The domestic blocks proposed will boost the housing supply and increase the population in the Aldrich Bay reclamation district. Requisite utilities such as for gas, telephone, and electricity to be available to meet the building completion. Confirmation for use of the site was endorsed by the Committee on Planning and Land Development in March Liaison and coordination with the relevant utility companies is in progress. Aldrich Bay Phases 1, 2 and 3 are planned for completion in the year 2000/2001, the Phase 4 and NCC site is planned for completion in the year ISSUE 1 PAGE 9

26 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN A. Introduction (cont ) (2) Neighbourhood Community Centre The site also includes a small area originally earmarked for the construction of a Neighbourhood Community Centre (NCC). Home Affairs Department (HAD) has agreed to release this site for alternative use provided that some community and welfare facilities such as Community Hall, Social Centre for the Elderly, and Residential Care Home for the Elderly can be made available. The Housing Department, Home Affairs Department, and Social Welfare Department agreed to a joint development incorporating requirements for a Community Hall and other welfare facilities. The joint development will tie in with the implementation of the housing development. The Residential Care Home for Elderly will help to relieve the strain of providing residential care services as a result of the aging population phenomenon. The Social Centre for Elderly will meet the social and recreational needs of the elderly in the neighbourhood. The Community Hall will provide a proper venue for the holding of meetings and community activities for the benefit of local residents. The site shall be optimised to accomodate requirements of the Housing Department and other concerned government departments. The design of the NCC site has been developed in consultation with other concerned government departments. The proposed scheme has been developed to fully maximize site utilization to meet the clients requirements identified. ISSUE 1 PAGE 10

27 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design B.1 Site Opportunities and Constraints (1) Environmental Considerations (a) Site Mitigation Measures Due to close proximity of the Island Eastern Corridor (IEC) and Road 9/1, there are potential air quality and noise impact on the development. Environmental Assessment Study report carried out by consultants suggested the use of both direct and indirect measures to mitigate noise impact to the development. Findings in Traffic Impact Assessment (TIA) and Environmental Impact Assessment (EIA) for Aldrich Bay reclamation area include :- - Air sensitive land use should be set back at least 5m from Roads 9/2 and 9/3. - A set back of 20m from Island East Corridor and 10m from Road 9/1 is required for air quality reason. - Maximise setback of residential blocks and school from the Island Eastern Corridor and locate self protecting block or non-sensitive buildings such as carpark and podium to serve as noise screens. The Small Household Unit has a minimum of 5m setback from Road 9/3. The two Single Aspect Concord Blocks are setback at a distance of approximately 30m from the Island Eastern Corridor (IEC) and 10m from Road 9/1 as recommended in the EIA and TIA. The carpark podium and the SACBs are provided as noise screen to other buildings on site. ISSUE 1 PAGE 11

28 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (b) Domestic Blocks Air conditioning units to be provided to the HOS blocks in the SACB and NCB to overcome the noise problems. The environmental consultant suggests addition of vertical fins to the SACB for better noise mitigation performance. As per comments of Members of PDRC, air conditioning units are required for all HOS units. Air conditioning units and type I window insulation (openable well-gasketted window panes of 6mm thick) are proposed for the HOS Blocks 1, 2, 3 and 4. In addition Single Aspect Blocks are used as a direct noise mitigation measure to mitigate noise impact on the development from the IEC. The site area being less than 2 hectares, the noise abatement requirements under EPD Practice Note for Professional Persons (Pro PECC PN 1/97) of October 1997, are less stringent and addition of vertical fins in the SACB is not required. ISSUE 1 PAGE 12

29 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (c) Primary School A noise study was conducted based on the 18-classroom primary school layout, it was found that there was sufficient set back distance from the Island Eastern Corridor (IEC) and adverse air quality impact is not expected. Based on the concept proposal submitted, EPD required that all windows be provided with openable well-gasketted window pane of 6mm thick and the following affected rooms to be fitted with air conditioning system :- - 1/Fl. - Student Activity Room - 2/Fl. - Computer Preparation Room Computer Learning Room - 3/Fl. - Music Room, Art and Craft Room Due to changes of school requirement, different layout from the Concept Proposal is proposed, the buffer distance from the IEC is being reviewed with EPD. Air conditioning units will be provided in the affected classrooms except the student activity room; and openable well-gasketted window panes of 6mm or 8mm thick will be provided to all classrooms in the primary school to mitigate noise impact. (Note : window pane of 8mm thick will be provided to classrooms which will experience a noise level in excess of 75 db(a).) (2) Drainage Reserve The portion of site on the west side of the drainage reserve is a narrow strip of land. The NCC and Welfare complex to be designed to fit into the site proposed. A ailor made NCC and Welfare Complex is needed to fit into the narrow site. A linear building form for the NCC and Welfare Complex is proposed for the narrow site. ISSUE 1 PAGE 13

30 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (3) Domestic Block on Carpark Podium The design of the domestic block on the carpark podium is constrained by the setback requirement and noise impact of the IEC. B.2 Built Form As part of the Metroplan Selected Strategy approved by ExCo., the Aldrich Bay reclamation area is regarded as a Visually Prominent New Development/Redevelopment Zone. The built form should be in appropriate scale and treatment to provide the right impact on the urban fringe with setting of the Victoria Harbour. (1) Development Ratio and Plot Ratio Development Ratio (DR) : 8.12 Plot Ratio (PR) : 8.48 The carpark was recommended at SPC meeting in May 1998 to be located at the southern side of the site. Development Ratio (DR) : 8.12 Permitted Plot Ratio (PR) : The end result of the design is one Single Aspect Concord Block and one New Cruciform Block on top of a carpark podium at the eastern side of the site (Please refer to A.8 of Appendix II for details). Development Ratio (DR) : 8.72 Plot Ratio (PR) : 8.57 (HOS) 8.56 (HOS + rental + welfare facilities) ISSUE 1 PAGE 14

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32 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (2) Altitude of Buildings and Provision (a) Single Aspect Concord Blocks The blocks sit on a transfer plate on top of the carpark podium. The height of building is truncated to 37 storeys to meet the building fire services requirements for 41 storey above ground without a refuge floor. The proposed SACB on top of the carpark podium is 37 storeys high with design modifications and transfer structure to suit the layout of the four storey carpark. The other proposed SACB is on grade and 41 storeys high. (b) Neighbourhood Community Centre and Welfare Complex 17 nos. storeys of Small Household Units and 3 storeys of the Residential Care Home for the Elderly was planned. According to the uide to Small Household Development there is a restraint on building height of Small Household Units, the tallest not to be more than 20 storeys above ground. 16 floors of Small Household Units are provided instead of 17 (as stated in SPC Paper No. 24/98), one floor being used to accommodate supporting facilities of the Residential Care Home. This results in a reduction of 28 housing units. The height of Social Centre of the Elderly and Residential Care Home of Elderly should not be more than 24m above ground according to SWD Client Brief. The Residential Care Home for Elderly is situated at first to fourth floor thus fulfilling the requirement of not more than 24m above ground. Other social welfare, health and community facilities are preferred to have access from ground floor. The Social Centre for Elderly is situated at ground level for ease of access. ISSUE 1 PAGE 16

33 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (3) Block Type Standard New Cruciform Blocks and Single Aspect Concord Blocks are used, which are suitable block types for this site. (4) Structural Aspect for Non-Standard Buildings Choice of block type to optimize the site potential. (a) New Cruciform Block (b) The proposed New Cruciform Block on top of the carpark podium is 37 storeys high with design modifications and transfer structure on two wings of the block. The other proposed New Cruciform Block is on grade and of the standard 41 storeys. Single Aspect Concord Blocks The Single Aspect Blocks are proposed to meet the site constraint with use of Concord flat modules. (a) Single Aspect Concord Block on Carpark Podium The two Single Aspect Blocks sit on a transfer plate with columns to match with the carpark floor layout below. To suit the limited land available for an efficient carpark layout, Single Aspect Concord Block and New Cruciform Block on top of the carpark podium are proposed with 3.5 meter and 3.0 meter deep transfer structure for transition into a column and beam construction of the carpark podium. Mitigation measures in the structure shall be considered to minimise adverse aesthetic effect due to ground settlement of filled sites. Downstands from ground beams are proposed along building edges to minimise adverse aesthetic effect which could arise from subsidence in adjoining grounds. ISSUE 1 PAGE 17

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35 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (b) NCC and Welfare Complex Transfer structure is required to transit the cross walls of the Small Household Units into columns in the Residential Care Home for the Elderly. Transfer girder structural system to be explored. Frame structure to be explored to allow colum-free space especially for the Community Hall. A change of structure from walls by a transfer girder system into columns at fifth floor level is proposed. This will free up space for design flexibility in the welfare facilities below. Beam and column structure is proposed for ground floor to fourth floor of the Block, a portal frame structure of span about 18m is proposed for the Community Hall with free-column space. (a) Small Household Development Harmony Annex 1P/2P flat units are chosen as the basic module to achieve the flat production requirement. No. of Flats 1P/2P = 340 1B = 34 2B = 68 Total = 442 Harmony Annex 1P/2P flat modules to be used for this project and other similar NCC sites. Small Household units are based on Harmony Annex 1P/2P and 2P flat modules. No. of Flats 1P/2P = 144 2P = 174 1B = 32 2B = 64 Total = 414 (As requested by the PDRC to explore on the feasibility of incorporating more 2P flats in the SHD, 174 nos. of 1P/2P flats are changed to 2P flats.) ISSUE 1 PAGE 19

36 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (5) Flat Mix 1B & 2B flats to be approximately 22% of the total numbers of flats The total number of family flats should be less than 25% as stipulated in WGMBI No. 9/97 1B and 2B flats provided in Small Household Development (SHD) are 23% of the total number of flats. The total number of flats in the Scheme Design is less than the Concept Proposal in SPC Paper No. 24/98 because of loss of one floor for supporting facilities required by the Residential Care Home for the Elderly. (b) Residential Care Home for the Elderly Dormitories to be designed for 4-6 persons. On each typical floor, there are 9 nos. 5-person flats, 1 no. 2-person flat and 1 no. 3-person flat. The flat modules are in line with modules for the SHD units above. (c) Flat Number Provision in SPC Paper No. 28/97 Provision in the design : Flat SHD NCB SACB Flat SHD NCB SACB 1P/2P 340 1P/2P 144 1B 34 2P 174 2B B 32 3B B B ISSUE 1 PAGE 20

37 Total Flats No. = 1674 Total Flats No. = 1630 ISSUE 1 PAGE 21

38 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (6) Household Size and Population The total number of flats is within the 10% adjustment limit of the approved Planning Brief for all phases in the Aldrich Bay Reclamation Area Housing Development. (a) Design Population The design population in the entire phase is The design population of the entire phase is Block Type Average Househol d Size No. of Flats Population a)ncb 3.26 X 760 2, b) SACB 3.26 X 456 1, Flat Type Occupanc y Rate X c)shd 1P/2P X 2P B B Total Population 4, ISSUE 1 PAGE 22

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40 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (b) Small Household Block Small household units based on Harmony Annex 1P/2P unit modules to be used. 1B and 2B Family flats in the small household development is based on Harmony 1 flat modules Small Household units 1P/2P unit IFA = 16.38m² 1B unit IFA = 34.44m² 2B unit IFA = 43.26m² Small Household Units proposed : 1P/2P unit IFA = 16.38m² 2P unit IFA = 20.13m² 1B unit 1FA = 34.44m² 2B unit IFA = 43.26m² (c) Residential Care Home for Elderly (RCHE) Residential Care Home for Elderly dormitories at 6.5m² per capita. Household size for dormitories of Residential Care Home for Elderly proposed are : (d) New Cruciform Block (NCB) 5P unit = 32.5m² (6.5m²/person) 3P unit = 19.5m² (6.5m²/person) 2P unit = 13.0m² (6.5m²/person) (e) Single Aspect Concord Block Standard NCB flat modules to be provided. Household size for NCB are : 2B = 37.76m² 3B = 51.85m² Standard Concord flat modules to be provided. Household size for SACB are : 2B = 47.01m² 3B = 60.36m² ISSUE 1 PAGE 24

41 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (7) Carpark A split level carpark layout was proposed with the drainage reserve at ground level bisecting the carpark into two halves. Efficiency of carpark and decking over the drainage reserve should be considered. (a) Four storeys carpark podium with one 37 storeys Single Aspect Concord Block and one 37 storeys New Cruciform Block is proposed. No decking over of carpark podium above the drainage reserve is proposed. (b) The carpark design is based on the uidelines for Design of Carpark in Public Housing Development with natural ventilation. (8) Disposition and Orientation of Blocks Setback distances, road alignment and site orientation was incorporated. The disposition of blocks is arranged to fulfill the prescribed window requirements. ISSUE 1 PAGE 25

42 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (9) Social Welfare Facilities Welfare facilities to be accomodated in the lower floors of the NCC and Welfare Complex. Provision of welfare facilities shall meet the Net Operational Floor Area (NOFA) requirement which comprises of a summation of all internal dimensions/spaces. The requirements of offices, interview room, common room, activity room, club room, pantry and store for the Social Centre for Elderly is 132m² NOFA. The Social Centre for Elderly is proposed at ground floor in the NCC and Welfare Complex with an NOFA of 132m². b) Residential Care Home for the Elderly The requirements of the Residential Care Home for the Elderly are 150 nos. care and attention bedspaces together with the supporting facilities such as nurse duty rooms, sick bays, physio- therapy room, dining rooms etc. with total NOFA of 1,935m². The requirements of the Residential Care Home for the Elderly are accomodated in the first to fourth floor of the NCC and Welfare Complex, with total NOFA of 1,935m². ISSUE 1 PAGE 26

43 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (10) Community Facilities (a) Community Hall The Community Hall is to be incorporated as part of the NCC and Welfare Complex to maximise site utilisation. (11) Primary School A-18 classroom primary school was proposed with a site area of 3950m². The requirements of the mutipurpose hall include stage, conference room, ancillary management office and store room, with an NOFA of 593m². A primary school is necessary to alleviate the shortfall of primary schools in the District. The Education Department (ED) requested a 24- classroom primary school with school site area of not less than 4100m². Agreement was sought from DLO/HKE and Architectural Services Department was consulted. The basketball court can be elevated with parking spaces under it, all within the school boundary. The Community Hall and its ancillary facilities are proposed at the ground floor of the NCC and Welfare Complex with an NOFA of 593m². The Scheme Design generally satisfies the requirements as listed in Schedule of Accomodation provided by the Social Welfare Department. A revised layout accomodating a 24-classroom primary school of the new Arch SD 2000 Design is proposed with a school site area of 4108m². The basketball court is placed on the roof of a service block accomodating the school carparks and plant rooms. The school boundary proposed in the Scheme Design layout was accepted by ED. (memos ref. (17) in ED(BS)298/B/396/80 dated and (23) in ED(BS) 298/B/396/80 dated from the Director of Education) ISSUE 1 PAGE 27

44 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) B.3 Pedestrian and Vehicle Circulation (1) Vehicular Ingress/Egress (a) Estate Road For Phase 4 and NCC site the main ingress/egress is via the entrance off Road 9/1. An Automatic Carpark Control System for traffic control is requested at the estate road entrance. Automatic Carpark Control System and Control Kiosk are proposed at the estate road entrance for traffic control of ingress and egress. (b) Primary School Ingress and egress for the Primary School is via estate road of Phase 1 off Road 9/1. (2) Green Mini Bus Terminus (GMB) The GMB stand location, layout, and ingress/egress have been agreed with Transport Department (TD) and Highways Department (HyD). The GMB stand is located at the north west corner of the site with ingress from Road 9/2 and egress at Road 9/3, as agreed with TD and HyD. ISSUE 1 PAGE 28

45 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (3) Vehicular Parking Provision Functional Area Provision Required Actual Provision (a) Residential Care 1 no. parking for 16- Home for Elderly seater van (RCHE) 1 no. loading bay 1 no. ambulance lay-by RCHE 1 no. parking 16-seater van 1 no. loading bay 1 no. ambulance lay-by (b)social Centre for - Elderly (SCE) SCE - (c) Community Hall (CH) 1 no. loading bay CH the loading bay is shared with the RCHE (d)small Household Development (SHD) Taxi-drop off/pick up area SHD Taxi-drop off/pick up area (e) Single Aspect Concord Blocks domestic blocks (SACB) 2 nos. loading bays SACB 2 nos. loading bays (f) 2 New Cruciform Blocks domestic blocks (NCB) 2 nos. loading bays NCB 2 nos. loading bays (4) Carparking Space Provision ISSUE 1 PAGE 29

46 Private Cars 244 spaces (1:5) Light GoodsVehicles 6 spaces (1:200) Motor Cycles 12 spaces Same as Concept Proposal Carparking Provided : Private Cars HOS spaces (1:5) Rental - 7 spaces Light Goods Vehicles HOS - 6 spaces (1:200) Rental - 1 space Motor Cycles 12 spaces ISSUE 1 PAGE 30

47 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (5) Carpark Entrance Effective means of control to be provided at the carpark entrance A shroff office is proposed at the lift lobby to the carpark podium. No Automatic Carpark Control System is required at the carpark entrance as advised by the Housing Management Branch (HM/D&V(I) memo dated ref. HD(H) CP/DV/P11/11/148X). (6) Pedestrian Circulation Covered walkway connection to Aldrich Bay Phase 2 to be explored. a) Security of covered walkway adjoining domestic blocks should be given due consideration. b) Covered walkway linkage of domestic blocks with all major facilities such as Commercial Centre/Bus Terminus etc. within the estate where possible. c) Maintenance and management responsibilities to be resolved at early stage for any covered walkway linkage between HOS and rental portions. Covered walkway incorporating light structures and building canopies are provided to link all blocks. They are strategically located to avoid conflict between vehicular traffic and pedestrian traffic. The walkway system is designed not to disturb the main landscaped area and provides linkage to the Phase 2 works for access to the Commercial Centre and Bus Terminus etc. This necessitates modification to the Phase 2 works and liaison with the Consultant Architect is required. ISSUE 1 PAGE 31

48 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (6) Welfare Facilities Entrances and circulation pattern to be defined. (a) The entrances to welfare facilities at ground floor should be separate from those for access to the domestic units on upper floors for security reasons. (Ref. HD(H)CP/DV/P11/11/148IX dated from SHM/D&V) Separate entrances and lobbies are provided at ground floor of the NCC complex. (b) A separate stretcher lift and ground floor lobby is to be provided for the Residential Care Home for the Elderly (Ref. HD(H)RW10(II) dated ) from SHM/RW. Separate lift lobbies/staircases for RCHE are incorporated in the design. In the event of breakdown, the RCHE residents could make use of the stretcher lift in the adjoining SHD lobby. (7) Carpark and Single Aspect Concord Blocks (SACB) No connection to SACB with direct access from the carpark floors for security reason. (a) Combination locks are proposed at exit doors to podium for the two SACBs for security control. (Ref. : HD(H)CP/DV/P/11/11/148(X) dated from SHM/D&V) For security reasons, lifts serving the SACBs will not stop at carpark levels and residents will have to use transfer lifts/staircase for access to and from the carpark. Combination locks will be provided to both ground and podium level exits of the SACB and NCB on top of the carpark podium. Lifts serving the blocks do not stop in the carpark floors. Residents from blocks will have to use transfer lifts in the carpark floors. ISSUE 1 PAGE 32

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50 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (b) Provision of two carpark transfer lifts are required. Two carpark lifts are provided to serve the carpark users and residents for access to the play areas and landscape areas on the podium roof. (c) CCTV cameras to be installed in all lifts, staircases and strategic locations inside the carpark. (Ref : HD(H)CP/DV/P/11/11/148(IX) dated from SHM/D&V) CCTV cameras will be incorporated in all lifts, staircases and strategic locations inside the carpark. B.4 Open Space Structure (1) Central Open Space Open space is provided around the buildings. Landscaping to be designed in a safe and secure manner to avoid creating nuisance to the nearby residents. A central open space features as the focal point of Phase 4. It is integrated with the walkway system providing access to the building blocks. The covered walkway and recreational facilities with sitting out areas will be detailed to match the overall landscape design concept of the development. ISSUE 1 PAGE 34

51 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (2) Podium Landscaping Landscaping areas are also provided at podium roof of the carpark. They include active and passive recreational spaces where residents could meet and socialise. (3) HOS/Rental boundary Clear delineation of HOS and rental boundary Clear delineation of boundary between rental and HOS estate is provided by pavement curbs, fencing and differentiated paving colour or pattern. (4) External Paving Consideration of effects due to ground settlement Kerb planters with limited use of hardpaving are proposed to mitigate the effect of ground settlement. (5) Local Open Space Local open space provision m² Open space on roof of the carpark and Community Hall could be accounted for the area required. HKPSG 10ha/100,000p Theoretical Provision 4,874m² Scheme Design Actual Provision 4,887m² The open space in the Scheme Design is reduced on account of enlarged school site area required. ISSUE 1 PAGE 35

52 PART I MASTER LAYOUT AND SCHEME DESIGN CONCEPT PROPOSAL CLIENT REQUIREMENTS MASTER LAYOUT AND SCHEME DESIGN B. Evaluation of Master Layout and Scheme Design (Cont ) (6) Recreational Facilities Children Play Areas 430m² Badminton Courts 1 no. Table Tennis Table 1 no. Split between passive and active areas in a ratio of 2 : 1. Children Play Area 572m² Badminton Court 1 no. Table Tennis Table 3 nos. The Ratio of passive to active areas is 2:1 ISSUE 1 PAGE 36