The information in this document is intended to be used as guidance material only, and is in no way a substitute for the NCC and related State and Territory legislation. The information in this publication is provided on the basis that all persons accessing the information undertake responsibility for assessing the relevance and accuracy of the information to their particular circumstances.

© 2017 Commonwealth of Australia and States and Territories of Australia

www.abcb.gov.au

PERFORMANCE SOLUTION CASE STUDY: PLUMBING

MANHATTAN ON THE PARK APARTMENTS

SITUATION OVERVIEW The 17 storey Manhattan Apartments are a mixed-use residential apartment complex containing 330 residences and ground floor retail. The apartments are located on a block with a 150mm sewer tie; however, the total fixture unit load for the new building found that the apartment building required a 225mm main drain.

Alongside the builder, several expert advisors were engaged to design and deliver a drainage solution to meet the requirements of the fixture unit load, including a hydraulic consultant and engineering firm, Sellicks Consultants. The solution required 80m of utility main to be replaced at an average depth of 4m. Early calculations indicated the delivery of this Performance Solution would come at a huge cost; however, the design team produced a solution that ultimately reduced costs associated with the construction of the building.

PROJECT HIGHLIGHTS

Name: Manhattan Apartments

Location: Canberra, ACT

Project Type: New Construction

Building Type: Multi-unit residential

Performance Solution: Plumbing

Architect: May + Russell Architects

Engineering consultancy: Sellicks Consultants

Hydraulic consultancy: Heriot Watt University (Scotland)

The information in this document is intended to be used as guidance material only, and is in no way a substitute for the NCC and related State and Territory legislation. The information in this publication is provided on the basis that all persons accessing the information undertake responsibility for assessing the relevance and accuracy of the information to their particular circumstances.

© 2017 Commonwealth of Australia and States and Territories of Australia

www.abcb.gov.au

PERFORMANCE SOLUTION CASE STUDY: PLUMBING

PERFORMANCE SOLUTION• The Performance Solution was based on the equivalent

population (EP) method outlined in the ActewAGL Water Supply and Sewerage Standard. It was further verified by the Probable Simultaneous Demand (PSD) solution detailed through the Plumbing Code of Australia (PCA) 2012, which yield a main horizontal collection drain diameter of 150mm.

• The proposed Performance Solution deviated from AS/NZS 3500.2 with regard to the sizing of the main horizontal collection drain — AS/NZS 3500.2, which is referenced as a Deemed-to-Satisfy solution in Parts C1 and C2 of the PCA. This solution stipulated a pipe diameter of 225mm be used for the main horizontal collection drain.

• A mix of Assessment Methods, including Expert Judgement, were used to evaluate the design, backed by extensive research findings conducted at the Heriot-Watt University in Scotland.

• The modelling demonstrated that when the drainage system operated during peak periods, the size of the main drain would be capable of removing all waste water without losing amenity for the residents and building users.

THE FINAL DESIGN INCLUDED:• The internal drainage system of the building suspended in the basement connecting 32 vertical stacks

• A 150mm elevated drainage system with estimated peak flow rates of 6 l/s – 7 l/s

• Flow rates that correspond with depths of 70mm – 77.6mm, allowing adequate free air flow across the top of the drainage system.

BENEFITS: • Delivered a drainage solution that did not adversely affect residential or commercial amenity

• Reduced costs associated with the construction of the building

• Additional research into the flow characteristics within a drainage system.