Case Studies


Shek Yam Estate Phase 3


Notable Features
bullet Construction waste reduction/recycling program
bullet Reduced construction waste due to use of factory manufactured precast concrete elements
bullet Application of large panel steel formwork
bullet Use of drywall for the internal partitions
bullet Use of aluminium slab formwork
bullet Use of precast facade
bullet Use of precast staircase
bullet Use of precast cooking bench
bullet Use of prefabricated door sets
bullet Use of spray plastering
bullet Use of gondola to apply external finishes
bullet On-site sorting of waste
bullet The wastage for concrete was 2.5%.
bullet The wastage for reinforcement was 8 %.
bullet The wastage for tiling was 5%.
bullet Metal containers were used for site office
bullet Reuse of surplus steel bars
bullet Reuse of corrugated steel hoarding

Basic Information
bullet Location: Shek Yam
bullet Building Type: Residential 
bullet Contract Period: 27 months
bullet Gross Floor Area: 109,449m2
bullet Client: The Hong Kong Housing Authority
bullet Architect: Dennis Lau & Ng Chun Man
bullet Structural Engineer: Maunsell Consultant Asia Ltd.
bullet E&M Consultant: Parsons Brinckerhoff (Asia) Ltd.
bullet Quantity Surveyor: Frank & Vargeson (H.K.) Ltd.
bullet Main Contractor: Shui On Building Contractors Ltd.
bullet Contract Sum: HK$ 780 million

The Shek Yam Estate Phase 3 was a residential building project and the following major items were executed under this contract:
bullet Four 41-storeys Concord Blocks
bullet One multi-storey carpark building
bullet One pedestrian footbridge
bullet All associated drainage and external works
bullet Road widening and lay-bys

  Plastering and Finishing
Since the precast wall and floor slabs, as well as the factory made internal walls provided a very smooth and accurate surface, thick plaster was not necessary. Plaster dropping on floor during the finishing process, sometimes accumulate to a thickness of 30mm over the whole floor area, can hardly be avoided in traditional cement sand plaster. However this situation was not happened, as sprayed plastering was adopted on this site. 

  Waste Management
  bullet On-site sorting of waste
  Separation of waste was not performed on site except soil was stored separately for backfilling of external works. Steel refuse chute was installed to discharge the waste material to the ground floor for each block. However, there was no separation of paper, cans, lunch boxes, plastic conduits and rubble, etc. The problems associated with separation of waste on site were the extra labour required and extra trucks required for different types of waste. If on-site sorting of waste was to be carried out, distributed separation was preferred. It was also suggested to use two outlets at ground floor to facilitate the discharge of different types of waste.
  bullet Material Control


The wastage for concrete was 2.5%.
bullet The wastage for reinforcement was 8 %.
bullet The wastage for tiling was 5%.


A mock up floor/flat was used to the control the use of material for the other floors.
  bullet  Use of recycled materials


Waste water was discharged to the waste water treatment plant and the treated water was distributed to the automatic tire washer and used for ground washing.

Reusable materials



Corrugated steel hoarding


Metal containers were used for site office


Surplus reinforcement was collected for reuse

Wall System
Large panel steel formwork was used to construct load-bearing walls of standard domestic floors. 

Dry Wall
The internal partitions were built of factory made lightweight concrete panels. Joints were minimized by the use of large size floor-to-ceiling panels. Cutting was not necessary because the size of the panels was tailored to suit the building, thus the amount of waste that would be produced during construction was further minimized. The time required was also less than the traditional brick or block construction. 
The factory made panel gave very smooth and accurate surface finish. However, it might not be acceptable because of its lower strength in supporting point load and resistance to impact.

Slab System
bullet Aluminium slab formwork

A 6-day floor cycle was adopted. This speed was more or less the same as those for private sector using traditional methods. However, the aluminium formwork could be used for three sites. It was considered cost effective to adopt aluminium formwork.


Precast Facade
The precast facade was manufactured in China and transported to the site for fixing. It was stored on the ground level and was hanged to the required floor by tower crane. 

The advantage is a fine quality finished facade achieved by such pre-fabrication method. On the other hand the problem of water leakage with this type of construction is primarily dealt with by the overhanging toe of the whole prefabricated unit which stops water penetration from the horizontal parts.

Precast Staircase
The precast staircase was constructed in 8 risers. The half landing was casted separately as in-situ part. Due to the smooth surface quality, no applied finishes would be necessary. A metal nosing strip was the only thing that was required to finish the stair. Naturally, construction waste was not arised.


Precast Cooking Bench
Cooking benches were also pre-fabricated elements. Bench top was cladded with 1 piece 0.8mm satin finish stainless steel sheet. The bench itself was of lightweight concrete and supported by 60mm concrete support, smooth finish and epoxy painted. 
The stainless steel sink was cast in lightweight concrete bed, 75mm thick, to afford strength to stand chopping and cutting. Earthing lugs were designed and built for both sink and bench.

Prefabricated Doorsets
Prefabricated door frames and doors were used in this project. These doorsets saved temporary timber support for door frame, thus reducing waste.

Contact of Contractor
Shui On Building Contractors Ltd.
12/F, New Kowloon Plaza, 38 Tai Kok
Tsui Road, Tai Kok Tsui, Kowloon
Tel: (852) 2398 4888
Fax: (852) 2396 4113


Low-Waste Buildings Technologies & Practices