Thursday, April 4, 2019
Advantages And Disadvantages Of Design And Build Method Construction Essay
Advantages And Disadvantages Of Design And Build Method Construction EssayWhile construction edits serves as a means of pricing construction, they also structure the allocation of risk to the various parties involved.The construction correction is a very extensive and unique in each leap out. In this world most of the discombobulates ar managed by contracts.And as a principle to manage the experience effectively we should first manage the contracts.The proprietor has the sole power to decide what showcase of contract preservation method acting should be used for a specific facility to be constructed and to set forth the borders in a contractual agreement.A firm has to choose the right delivery method which is meet to fox base and present its put forward offer to the engineer/client during tendering stage to enable it to present war-ridden price and win the see without compromising the functional and the quality of the project.Choosing the right method to deliver the pro ject will ease the project execution and give flexibility during construction as well as saving m peerlessy and quantify for a firm and by and by the same to the owner.It is important to beneathstand the risks of the contractors associated with different type of delivery methods.In this instant you whitethorn ask what the contract delivery methods ar and we should choose the right delivery methods.Projects delivery methods. in that respect ar three types of project delivery methods. In this section we will concentrate on externalize and Build because it s the best method for small and medium projects.1- Tender or bod- compress-build methodIn this type the owner/client will choose engineer to intention the whole project and get theApprovals from authorities then floating tender to choose suited contractor for the Construction under his supervision.In this type of method the client /engineer has full learn of the project and the contractor has to approve with full design given by the engineer. close suitable type of contract for this method is intumescency sum contract which the price given by the Contractor is fixed and the whole project is already designed and the scope of work is clear and fully detailed.2-indefinite quantity contract method under this type of contract there shall be no design and it is based on maintenance or repairing projects.Under this agreement the owner and the contractor will upfront set up prices for the labors and Equipments and markup etc3- Design and build method.The term design-build refers to a range of alternatives to the traditional project delivery system of rules.A useful air to look at design-build is by what it is non. Traditional design-bid-build is a segmented, sequential accomplish in which the owner first contractsWith a design professional to prep be detailed, suitable-for-construction plans and specifications (or Some durations has them prepared by its in-house engineers), then uses the detailed pla ns and Specifications to solicit agonistic bids for construction, and in conclusion awards the construction Contract to the low bidder.Design-build means a procurement process in which both the design and construction ofA project is procured from a single contractor.Usually, the design-build contract is awarded by some process new(prenominal) than competitive bidding Providing the best value (in price, features, functions and life-cycle speak tos)Thus, design-build differs from traditional design-bid-build in two ways. First, the design and construction comp 1nts are packaged into a single contract. Second, the single contract is not necessarily awarded to the low bidder after competitive biddingI-Why Design-Build? (Advantages)Potential Cost SavingsDesign-build has the potential to funk over-all project follow because the design-build contractor perform the design has a better feel for the construction cost of various alternatives, Thus discount keep an eye on up with a des ign that is less expensive to build and has an incentive to do so. An some other way to look at this advantage is that it moves value engineering cost reduction incentiveAfter contract award (with the contractor proposing cost-reduction ideas and sharing the savings with the owner) to pre-award (with the owner enjoying most of the cost savings).B. Earlier Project shutdownDesign-build may result in earlier completion and occupancy of the project because there is no utter period between completion of design and start of construction. Further, the design-build Contractor grass begin construction of primordial human bodys of the project (e.g. mobilization, billet utilities, Foundations) before design of later phases ( mental synthesis envelope, interior partitions, HVAC, electrical) Is 100 percent complete? This process sometimes is referred to as fast track.C. Reduced Claims ExposureDesign-build eliminates the liability gap. Design professionals end obtain restitution coverag e solitary(prenominal) for negligent errors and omissions, and virtually all design contracts limit the designers liability to such.However, there mess be non-negligent errors and omissions, which cost the owner money but for which the design professional is not liable. For example, a design professional may under apportion Reasonable subsurface investigations but fail to detect a swing outcropping that will require additional work.In the traditional design-bid-build approach, the owner warrants the justness of the plans and Specifications to the construction contractor.There can be design mistakes for which the owner is liable to the construction contractor under the Warranty of correctness but cannot transfer the liability on to the design professional.Even when the designer is in fact negligent, proving disregard can be difficult.The owner must obtain a certificate of merit from another design professional and then prove that the designer failed to meet the applicable profes sional standard of care, which requires expert testimony.On the other hand, the contractor usually can prove there was a defect in the plans that cost the Contractor money based on fact testimony alone.Thus, the owner may have to pack the cost.Design- build eliminates this gap because the design-bid build entity has no one but itself to blame For defective plans and specifications or differing site conditions.D. New TechnologiesPublic Contracts usually prohibits brand-name or mildew-number specifications unless theSpecification lists at least two brand names and is followed by the phrase or equal.This makes it difficult for traditional design-bid-build to reach innovative, proprietaryProducts where there may be only one brand-name and no equal.Further, substitution of a new or equal product for a standard product often is impracticable Because of the ripple effect.The designer designs the project around current coevals Products and substitution of new or equal products after bid ding can require revisions to structure, mechanical or electrical components to accommodate the new product.Who is going to pay for these ripple changes? Design-build resolves this line of work.The design-build contractor selects the equipment (right down to make and model number) and Then designs the building around the selected equipment, which is a more logical way to proceed.In fact, the design-build contractor can sometimes obtain free design assistance from equipment Manufacturers desiring that their new technologies be used.E. Over-All Project OptimizationDesign-bid-build can suffer from sub-optimization when individual project participants optimize their own positions, often at the expense of the over-all project.The total cost to the owner of a building element, such as the steel frame, includes the cost of the engineering to determine the necessitate steel sections plus the cost of the steel.The designer has little incentive to use a lancinating draw to achieve the min imum total ofStructural steel he optimizes his own position by using up only the design time necessary to Ensure that there is enough steel to meet solemness and seismic loads, often by employing Conservative assumptions that may result in more steel than necessary.So, the owner may save money on design but pay for it in steel.With design-build, on the other hand, the design-build entity has an incentive to use the Optimum amount of engineering. As long as an additional dollar of engineering will save more than one dollars worth of steel, the design-build contractor will spend the engineering time up To the point of diminishing returns when an additional dollars worth of engineering saves only a Dollar s worth of steel because both the cost of design and the cost of steel come out of the same pocket.This is not to say that design-build results in flimsy or less-safe structures. More (steel, cover, etc.) is not necessarily better. Simply specifying unembellished steel or concrete in one place because the engineer does not have the time or incentive to calculate exactly how much is actually needed does not improve the over-all deed of the building.A chain is only as strong as its weakest link. If the owner wants a building with high floor Loadings, less floor deflection or resistance to a bigger earthquake than requisite by code, then The way to achieve this is by placing that requirement on the design-build entity up front not by Hoping that the designer will throw in some extra steel or concrete because he or she does not have time in the budget to use a sharp pencil.F.Reduced Administrative BurdenDesign-build may reduce the administrative burden on the owner because there is one solicitation, one award and one contract to administer.G. Earlier Cost VisibilityThe total cost of the project is apparent earlier with design-build. In traditional design-bid-build, Construction costs are not known until bid opening, and it is possible to spend money on a des ign that the agency cannot afford to build. All too often, construction bids hap the budget, and the Project must be re-designed to bring it within the budget, thus delaying completion.H. Agency CM with Multi-Prime ContractsOne of the advantages of design-build can be achieved by a construction charge (CM) to Manage design and over-all project coordination and then contracting directly with several contractors, which are then managed by the CM.Construction project steering s services provided by a licensed architect, registered engineer, or licensed general contractor.Under this approach, the primaeval phases of the project (earthwork, site utilities, and foundations) can be placed under contract before design of the building shell and interior is 100 percent complete, and the structural steel and other long lead-time components can be ordered.Then, the contracts for the early phases can be awarded to follow-on contractors.There are two types of construction managers.An agency C M is a consultant to the owner an agency CM is not in the chain of privity between The owner and the contractor(s) and does not guarantee the cost of the work.An at-risk CM, on the other hand, essentially is a brokering general contractor.The at-risk CM is either in the chain of privity between the owner and the trade contractors or Guarantees that the aggregate price of the contracts will not exceed some maximum figure.Any individual or firm proposing to provide construction project management services shall provide Evidence that the individual or firm and its personnel carrying out onsite responsibilities have expertise and experience in construction project design review and evaluation, construction Mobilization and supervision, bid evaluation, project scheduling, cost-benefit analysis, claims Review and negotiation, and general management and administration of a construction project.Which type of contract is better for design-build?Most suitable type of contracts is lump sum co ntract because the owner has essentially assigned all the risks to the contractor, who in turn can be expected to ask for a higher markup in order to take Care of unforeseen contingencies.Beside the fixed lump sum price, other commitments are often made by the contractor in the form of submittals such as a specific schedule, the management reporting system or a quality control Program.If the actual cost of the project is underestimated, the underestimated cost will reduce the Contractor s profit by that amount. An overestimate has an opposite effect, but may reduce the portion of being a low bidder for the project.The scope of work, the price, the time of performance is already defined.Usually the contractors include border for contingencies in their bid price so the priceSmall and medium projects are most suitable for this kind of project where is the design is easy not Complicated and can be managed by one party.II-disadvantagesThe potential advantages of design-build do not com e without risk.A. Less Control.Under traditional design-bid-build, the owner has full control over the details of the plans and Specifications and does not publish them for bids until it is satisfied that they reflect its Requirements, including functional and aesthetic preferences.With design-build, the owner gives up some of this control. i.e., advancing the level of design through the design development stage (30 percent or so) before award of the design-build contract.Of course, by doing so the owner may give up some of the advantages of design-build.B. enquire for Earlier Requirements DefinitionWith design-build, the owner must lock in its requirements much earlier.With traditional design-bid-build, if the owner is a little fuzzy on its functional or aesthetic Requirements, it can clarify them during the design phase after if sees where the designer is heading.But with design-bid-build, post-award programmatic changes can be very expensive and disruptive.C. RecommendationSo, i f the city (country) rules are not certain what it wants, traditional design-bid-build may be the better alternative.D. Compliance with SubcontractorsThe Subletting and Subcontracting Fair Practices Act, requires that bidders list their subcontractors with their bids. This can be a problem for a design-build bidder. Without detailed design drawings, the subcontractors cannot precisely estimate costs.But, listing a subcontractor without a firm subcontract price puts the design-build contractor at a disadvantage in subsequently pricing the subcontract work.A listed subcontractor has the prime design-build contractor over the proverbial barrel. This is a manageable problem for a design-build contractor with many of the same type of projects in an Area, as a subcontractor can only get away with gouging the design-build entity once.Parking garages and housing are good examples of where the design-build entities work with a group of subcontractors on a repetitive basis, and subcontractors can estimate their work on a perspace. or.pre-square.foot.basis.Design-build contractor shall search for competitive bids for subcontracts not listed with its prime bid.The problem with this approach is that it depends on specific legislative authorizations that do not fool to the country.Thus, the safest approach may be to require listing of subcontractors at time of bid, even though this may result in either the subcontractors or the prime design-build entity including some contingency and mark-up.E. Payment bondsGenerally it is required a payment bond payable by the terms of the contract.However, when the design services and the construction are procured under a single contract, must the payment bond be in the full amount of the design-build contract or only in the amount of the Construction portion? Logically, it would seem that 100 percent of the construction portion would fulfil the intent of the statute.
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