By Okechukwu Onwuka
Today, weâ€™ll discuss the often misunderstood sequence and importance of communication between project design and construction. Viewed on a simplistic model, construction is the process or activity that takes place after design is completed. This view might explain in part the reason why many technical people still consider these two keyÂ project aspects as not only different but also treat construction as an area that construction contractors have to deal with.
The practical implication of this is that projects that complete the facility or building design without rigorous consideration of constructability and fabrication issues end up paying a huge price in material wastage, schedule overruns and several on-site modifications that could well have been avoided. A very simple example is a residential housing design and construction project. On paper, an Architect may complete a design that is filled with many beautiful looking angles and curves which a potential owner may find quite appealing.
People who have experience in construction know that translating design curves into reality is a challenge in our country. The challenge derives from the poor quality tools, equipment and methods available to fabricate the moulds and erect them in perfect symmetry. As a result, the erection process takes too long with inevitable higher costs or they are erected in a hurry without finesse resulting in horrible looking contraptions. Such poor methods also lead to significant material wastage. Another challenge is the poor understanding and appreciation of quality standards among building technicians in Nigeria.
When the building industry is viewed from a holistic standpoint, youâ€™ll observe that the level of waste on a typical construction site can be described as criminal in some cases. The principal areas of building waste include Finishings (Screeding, Plastering, Tiling), Block Work, Formwork, Material Handling and Scaffolding. If you are paying the bills on a project and see the quantity of cement mortar that is wasted in plastering and tiling, your heart might fail you. Add that to the percentage of tiles that are wasted during laying through cuttings and damage during transportation to site. If a designer was to make the extra effort to consider the requirements of the construction phase with the understanding that the design is expected to be 99.9% of what is to be built, the results will be better.
For instance in tiling, by pre-selecting the type and standard dimensions of the tile to be used in various areas of the house or complex, the designer can make minor adjustments to space dimensions to accommodate complete numbers of tiles without the need to break or cut any tiles during installation. In the same way, arcs that will pose significant challenges to effective and efficient construction in our environment will give way to shapes that are easier to implement without losing the aesthetic quality.
In much the same way for Oil Product Tank Farms, choosing the size of a Storage tank is best made by considering available sheet metal sizes to ensure there is zero waste of sheets when the tanks are being fabricated. Designing beams and columns in buildings can also benefit from the use of dimensions that not only meet technical requirements for Integrity and strength but also allow the use of available formwork materials without complicated preparation processes and costs.
When designing piping and pipelines for Oil or Gas transmission projects, the experience of seasoned construction people will be very valuable to the design team. Where a design team may specify using say a 10â€ pipe of Standard Wall thickness and High Yield Strength material (i.e. API 5L, X82 Material). Although X82 material is stronger than X42 Carbon Steel, it is however more difficult to weld effectively in the field. Regular welding techniques may result in extensive welding defects and may also slow down the field pipeline laying process.
An alternative design specification may be to use a pipe of greater Wall thickness but made of standard material (X42 Carbon Steel) which is easier to weld. What if a disjointed Design and Fabrication team effort on a 100 Km pipeline project results in procuring and delivering to site about 9,000 pipes of the difficult to weld material before realizing the associated consequences?
A good way to resolve such expensive disconnections is to make experienced construction people take part or make valuable input to the design group before the designs are issued for construction. Architects and Engineering Design teams should not take comfort in saying that â€œthere will always be modifications on siteâ€ and as such get careless in making the effort to save costs for the project sponsor. We should borrow from the practice by Vehicle Manufacturers and Product Designers. Although a car may have up to 1,000 different parts that are produced in more than 10 different companies spread over 7 countries, nothing is left to uncontrolled chance.
Every design and specification is made to achieve perfect fit during the coupling stage. Two reviews or studies that should be carried out before finalizing a design, irrespective of project type are Constructability Review and Pre-Construction Risk Assessment. The team membership for these reviews must include experienced construction professionals in the focus industry. The experience and knowledge of the facilitator is also important. Project Owners MUST demand for these reviews. It would save you costs beyond your imagination.
GOLDEN EAGLETS: Was it right for the Nigerian fans to walk out on the young Golden Eaglets when they went 3-0 down against the Germans at the Nigeria 2009 soccer match in Abuja? This is a clear act of non-patriotism and such people have no right to demand hard work and performance from others because it clearly shows that they are lazy opportunists who derive pleasure in reaping without sowing. That was simply shameful