Construction has two phases, one is Analysis and Design, and the other is Execution at site. Analysis and design is done after the site investigation and the type of structure demanded by the client. This is the most important phase of the construction process, as the end product of the construction depends on this. Any minor fault in the design may lead to huge disaster and loss of life and property, so it is done by the most experienced persons.
A person can be master in analysis and design, but may not be a good designer unless he has experience from the site exposure. The real experience in construction comes from the site, as we see the construction happening in front of our eyes and find the mistakes in design and learn from them. A person with good experience at site can be a good designer as he has some idea about the construction problems being faced at site. So, to be a good designer, we must start from site.
Construction is the process of converting imagination into reality. We imagine something not existing, then draw its plan, analyse, design and then execute at site to get out imagination into reality.
Following are the types of construction in general:
1. Building and infrastructure construction
2. Heavy construction
3. Industrial construction
For any large construction, we follow the steps as below:
4. Handing over
Before tendering, we do site investigation and prepare an approximate design of the structure and applies some empirical formula, derived based on experience, to calculate the approximate cost of the project so as to quote our price. After the tender has been awarded, the contractor prepares the detailed layout of the project after analysing and designing. This detailed drawings are then sent to site after approval from the client for execution purpose. And after the execution part is over the product is handed over to the client.
Construction Contract Types
1 Lump Sum typically used with Design-Bid-Build method of project procurement.
Lump sum contract, sometimes called stipulated sum, is the most basic form of agreement between a supplier of services and a customer. The supplier agrees to provide specified services for a specific price. The receiver agrees to pay the price upon completion of the work or according to a negotiated payment schedule. In developing a lump sum bid, the builder will estimate the costs of labor and materials and add to it a standard amount for overhead and the desired amount of profit.
2 Unit Price
In a unit price contract, the work to be performed is broken into various parts, usually by construction trade, and a fixed price is established for each unit of work. For example, painting is typically done on a square foot basis. Unit price contracts are seldom used for an entire major construction project, but they are frequently used for agreements with sub-contractors. They are used for maintenance and repair work. In a unit price contract, like a lump sum contract, the contractor is paid the agreed upon price, regardless of the actual cost to do the work.
3 Construction Management
In this delivery method a Construction Manager (CM) is selected to construct the project based on fully completed drawings and specifications prepared by an architect hired by OSU. The CM provides advice during design. The CM is selected based on competitive proposals from three to five firms.
The CM approach differs from the other methods in the following ways:
The project manager approves the CM’s construction management staff and their required time on the project.
The CM provides pre-construction services, including construction cost estimating and constructability review, throughout programming and design.
The project manager approves the subcontractor bidders list and the selected subcontractors.
Although this method is not often used due to the Owner’s inability to control quality, difficult to confirm adherence by the Contractor to specific materials, and it is difficult to make changes with this method.
Design-Build is very old method that fell out of use until recent years. In this process the owner selects one contractor to both design and build the project. In Oklahoma this typically means that the owner selects a builder who then hires the design team as required. Design-Build is primarily intended to save time. Like Construction Management with pre-construction services, the designers and builders work together from the beginning, the design effort can be substantially reduced. It is not necessary to prepare drawings in great detail if the builder already understands what needs to be done.
A construction process consists of following:
· Design Team
· Financial Advisors
· Legal Advisors
· Interaction of expertise