PWWA MEMBERS FEEDBACK ON DESIGN & BUILD ARRANGEMENTS FOR WATER INFRASTRUCTURE DEVELOPMENT
Mid Coast Water Utility Australia Twinning with Tonga Water Board
Our experience in our small Australian utility is that a 'design and build' contract can result in tenders where the construction contractor dominates on price and good design is often sacrificed. Our utility likes separate design, separate build as the designer is under less pressure to provide the cheapest result and rather find the right result. However, you do need to know what you want to inform the designer. The exception is small items such as skid mounted chemical dosing or filtration, where we think that a design and supply arrangement is fine.
Brendan Guinea, Executive Manager
American Samoa Water/Power Authority
We rarely use Design & Build as there are usually too many variables to manage.
Utu Abe Malae, CEO
Hunter Water Utility, Australia twinning with Water Authority of Fiji
In Australia, best practice in project procurement is achieved through first getting a good understanding of your objectives and the situation prevailing. The various project delivery methods (design and then build, early constructor involvement with design and build, design-build, build-own-operate etc) are then ranked as each project delivery method involves different risks and costs. A big consideration in the islands will be local factors relating to access, the level of competition, ongoing maintenance, quality of build etc)
James Keary, CEO
Palau Public Utilities Corporation
In general, Design/Build is an excellent method of engineering and construction procurement methodology especially when the scope of work is relatively clear, simple and no major unexpected circumstances are anticipated during the course of the project. During the planning and pre-design stage of the project, an agency should conducts relevant investigative studies or reports to provide important data for the agency to prepare a Basis of Design Report which spells out in relative detail the scope of the design and construction work of the project including relevant design criteria and parameters, applicable specifications and estimated cost of the project. At which time, the agency can make an informed decision to pursue or not the Design Build method of procurement for a specific project.
Without a clear design/construction scope (preliminary design) of work and other relevant information stated above, you will receive proposals with wide ranging in scope and costs and you will have no basis or criteria to evaluate and make selection of which proposal might meet your requirements the best.
Without the Basis of Design document, proposers of a design build project will have a tendency to over-design and over-estimate to make up for possible unforeseen circumstances in the design and during the construction. In general, this tends to be the cause for design build projects cost proposal to be much higher than the conventional engineering and construction procurement method.
Kione Isechal, CEO
Woods Pacific Ltd. New Zealand
The design build philosophy is a good one, provided that it is well thought out before going ahead. If not it has the capacity to be costly for the client and the net result will be bitter for everyone concerned.
The normal procedure is for the client to engage a consultant team to carry out the initial design through to the 50-60% stage. This means that there is sufficient detail in the design to allow a contractor to price it and minimise the risk in his pricing. At the award of tender to the successful contractor the design team is then novated across to the contractor and they complete the design. The design team then also carry out the site observation and issuance of As Built drawings etc. on behalf of the contractor.
The benefit is a shorter time scale to complete the project, with the client having a very clear idea from early on of what he is going to get. The contractor benefits from having the same team complete the job and the risk of a blow out in variations is minimised.
Downsides are the design team not willing to be novated across to the contractor, particularly is there is a history there from previous contracts. A new design team then has to be found to pick up from where the others left off. Any fundamental change in design philosophy can cause a problem for all parties and the risk of cost escalations.
Jack Out, Regional Manager