Design & Build Contractor Guide
The process of a design & build construction project can in general be categorized into four distinct stages:
- Planning
- Design
- Construction
- Operations
These are each described in the following sections below.
1) Planning Phase of a Design & Build Construction Project
In the planning phase, the customer (or project owner) will define their needs & wants of the building project, typically as part of a business planning process. For example, a business in manufacturing may want to expand production capacity in response to increased orders. This could be achieved through a number of means, for example: the production staff working overtime, the rental or purchase of a factory facility, the extension of an existing facility or, the construction of a new factory building on an existing site. The appropriate choice, therefore, driven by the underlying economic, social & natural environments.
2) Design Phase of a Construction Project
The design phase of a construction project can be sub-divided into four stages:
- the design concept phase
- the schematic design phase
- the design development phase, &
- the preparation of construction documents.
During the stage the customer (or project owner) will largely interact with the ‘design project manager’ or ‘lead designer’ of an design/architecture firm, who will assigned to managing the broader design staff toward the completion of the building design.
(i) The Building Concept Phase
In the building concept phase, the customer principally works with an architect firm to conceive an initial project concept. A number of project concepts may be developed; however, drawings at this stage largely consist of early stage sketches. In this phase, the following aspects of the build should be defined: * building location * building size, orientation & layout * alignment of with existing infrastructure, such as existing buildings & access roads
It is crucial to define these accurately & early-on for the future success of the design & build project. Any later realization that the site is not suitable, or the layout is not fit for intended use will have huge consequences on the later stages of the project.
(ii) The Schematic Design Phase
Here, a set of graphical documents are developed to add further detail to the initial design concept. These drawings will be produced using computer aided design (CAD), &/or building information modelling (BIM) software. These can be used to create:
- 3D simulated walkthroughs of the building concept
- 3D printed renders of the building concept
- 2D drawings of the site-plan, floor-plan, building sections & elevations of the building concept
These documents can be used to verify that the building concept can be built on the available site. At the end of this phase, a customer will receive an initial building schematic design package & cost estimate for review & approval by the customer. Note, however, that dimensions at this point are only defined on the macro scale i.e. full dimensions are not yet included – further refinements of the design & dimensions are made in the design development phase.
(iii) Design Development Phase
Once the initial schematic design & costing of the building concept are approved by the customer, the architecture firm will proceed to the design development phase. In this phase more detailed building specifications will be made to the building floor plans, sections & elevations – as well as – the layouts of structural, mechanical, electrical & plumbing systems. Full dimensions are now included, such as the position & dimensions of windows & doors, along with details of the materials to be used.
This further developed design – and corresponding updated cost estimate - will then be submitted to the customer for review & approval. If the design team has worked closely with a construction contractor, a preliminary construction schedule may also be submitted.
(iv) Construction Documents Phase
Once the design & development drawings have been reviewed & revised, it is then possible to work on the final phase of the design process i.e. to produce the construction documents. These documents will go into further detail & include details & specifications of materials, which can then be used to finalise the price of the building’s construction.
3) Construction Phase
The construction phase of a design & build project, can be sub-divided into: * The pre-construction phase * The construction phase (including control & administration) * The construction close-out phase.
(i) Pre-construction phase
Aim is to plan and prepare for construction – these include activities such as: pricing, project scheduling (logistics and phasing), pre-qualification of subcontractors and suppliers, solicitation and selection of specialty contractors, analysis and purchasing of materials and products, review of construction documents, including constructability analysis and assistance with obtaining sustainability certification.
(ii) Construction Phase (Including Control & Administration)
This phase will deliver the facility or infrastructure as it was designed. This phase includes the sub phase to oversee the construction, to enforce co-ordination among the project parties – focused on jobsite office activities.
(iii) Construction Close-out & Building Hand-Over Phase
The construction close-out phase involves the completion of all the construction tasks and gathers all documentation required to close-out the construction contract & complete the project. This involves field close-out, contractual close-out, financial close-out and in-house close-out analysis.
4) Operations Phase
Following the construction & hand-over phase, the building is ready to be put into operation by the customer – whether the building is intended for use, lease or sale. For the majority of customers, therefore, the design & build project is complete at the construction hand-over phase. It is, however, important to consider that a building may be the object of several other projects during its lifetime.
Post-completion projects include refurbishing, retrofitting the building facilities that were not defined.
