The Procurement Method of ELS Works - Research Proposal Example

The procurement method of ELS works. Introduction The of this analysis was involved in a project of West Northamptonshire Development Corporation (WNDC) as a quantity surveyor on behalf of his corporate employer for housing construction. The project was to construct a 14-storey building in the heart of Northampton town transforming from a market town to dynamic regional city. The project was to construct affordable homes and quantity surveying consultancy services had been undertaken by the employer. The project was under design and build contract scheme. As is with any project, timely completion was the aim of the Employer WNDC as their objective was to provide affordable homes as a social project in which cost overruns for any reasons could not be passed over to the consumer once the prices have been fixed. In this case, project was started after fixing predetermined prices and only after making sure that homes were sold out before commencement. Trouble started at the commencement stage itself. The contractors for the project found that subsoil surveys furnished in the tender were different from actual conditions. This meant foundation designs had to be modified resulting time and cost overruns. Cost certainty is one of the advantages of design and build contract as it is a fixed price contract. Hence the contractor has to bear the entire burden of cost except as may fluctuation clauses may apply. However, certainty of cost is not necessarily for the employer/client. Fixed price and single point responsibility entails more risk for the contractor. Since risk attracts premium, the contractor has the tendency to add a premium to absorb the extra risk. Thus design and build in fact is more expensive than traditional contract. Hence it may not be appropriate to pass too much risk to the contractor for high risk project. As a procurement method, design and build carries with combination of priorities. If aesthetic quality is the highest priority for the client, he can appoint a design and build contractor for architectural merit. If speed or money is the highest priority, a design and build contractor with record of meeting targets may be appointed. But the biggest disadvantage of design and build is that employer’s requirement must be unambiguous unlike in a traditional contract where it is subject to change. However, in design and build also variations occur and it has been a perennial problem on the industry. This leads to frequent claims and resultant litigations. A client reserving right vary requirement should not choose design and build procurement method. Contractual relationship in Design and Build would be as follows. Employer Design & Build contractor Employer’s advisers Architect/designers (Quantity surveyor) Structural Engineer Services engineers Sub- contractors There is no independent certification requirement in design and build contract. As such architect or contract administrator is not necessary to settle differences between the parties. There is no independent quantity surveyor responsible for preparing the basis for the contractor to rely upon. The quantity surveyor in the above relationship figure though not legally required, his role is essential as advice on costing and other economics are essential. No traditional form of quantity surveying is required in design and build form of procurement. Yet a contractor can have a quantity surveyor as part of his DB team. There is no bar on employer either to have a team of architects, quantity surveyors, engineers and others. As such, quantity surveyors have now become specialist client advisers in the absence of their traditional roles. JCT DB 05 suggests that Design and Build procurement method should be used where there is a need for detailed contract provisions, the employer has to prepare his requirements to be conveyed to the contractor who undertakes to complete the design besides execution of the works and where employer appoints an agent to administer the conditions. Key Issue The contractors claimed that subsoil conditions mentioned in the tender was not a warranty but a condition so that the employer WNDC should assume full responsibility for the extra cost and time to be incurred. The contractor had submitted as part of his tender sub-structure designs and detailed priced bill of quantities for 8 selected blocks in the selected foundation conditions. The designs for the foundations had been prepared on the assumption of subsoil conditions as had been furnished by the corporation in the bore-hole data. During the course of the work, tufa was discovered in quite a few areas that necessitated redesigning of the foundation and additional works to be carried out. As such the contractor claimed that there had been breach of implied condition on the part of the corporation. They claimed that they were entitled to be compensated by way of damages for breach of the condition. On the other hand, the corporation denied liability stating that there could be no such implied condition or warranty. Due to this, an impasse prevailed resulting in an abrupt stoppage of work with the risk of time overrun, cost overrun including payment of wages for the period of layoff. At this juncture, it may relevant to recall the writer’s experience in Hong Kong in respect of problems encountered in excavations and lateral support. Excavation has its own hidden issues and the surveyor must be aware of the consequences involved if sufficient precaution is not taken by the employer and the contractor. There is one concomitant issue of lateral support when ever is there is an excavation. This writer had the opportunity to come across excavation and lateral support issues in his involvement as a quantity surveyor in the project in Hong Kong. Before going into the project involvement, I would like to mention what it means in small projects. Often employer fails to realise that the contractor has based his tender on what are indicated on the drawings and specification rather than contractual terms and conditions. As such if the drawings and specifications are not made with professional skill, what the employer agreed to pay for will turn out to be quite different from what he had imagined. Unscrupulous contractor does not include a percentage profit so that his bid will be lower and he will be awarded with the contract. Once the award is in his hands, he will take the chance to price excessively for the extras to make up his profit. There had been instances in which the contractor hoped to collect as much as ten times the actual cost of the work done on extra. Unknown conditions must be considered as a risk as they cause much expense. Either the unknown conditions must be eliminated or the employer must assume the risk himself rather than pass it on to the contractor. If the contractor is asked to give lump sum bid, he would add cost of excavation as if it is a rock and charge three to four times the charge for common soil and clay. If the rock is only 10 %, then he would stand to gain. On the other hand it would be wiser on the part of the employer to stipulate that all estimates must be based on excavation with a power shovel plus a per cubic yard price for rock excavation in the event rock is encountered. This way, risk is assumed and the employer pays exactly for what he gets. If there is a building adjacent to the worksite, it can suffer damage as a result of construction work, any hazard must be reduced by careful investigation instead of asking the contractor to add a premium to cover a possible damage. In any event, the employer should notify the adjacent property owners by registered mail about his proposal to build and inform that he will exercise the caution a prudent man would take to prevent damage o other’s land. This rule law of lateral support which means support from side and maintains that it is immaterial whether or not excavation is done with due care. However, if the excavation on one piece of property causes neighbour’s land to slide in, settle or anyway change the contour, whoever digs will be responsible therefor. But if the precautionary notice has been given to the neighbour, it is the duty of the neighbour to take all required measures to protect his buildings. Hong Kong Project Design and construction of foundation and braced excavation at a reclaimed site at Waterfront The low lying Sheung Wan areas of Hong Kong’s Island’s western side were often being affected by flooding during heavy rain storms along with high tide. It used to get worse during extreme high tides when the sea level is higher than the ground level in that area causing seawater to flow back and overflow from manholes and gully gratings. To tide over this recurrent problem, a storm water pumping station was proposed to be built at the water front of Sheung Wan. The construction had already commenced in mid 2006 well before my involvement and was about to be completed by December 2009. The pumping station was meant to collect storm water from a net work of drains and discharge the water into the harbour through the high-powered submersible pumps and at the same time to stop the water from flowing backwards into the drainage system by a penstock. One key element of the project was the construction of the foundation for the pumping station called Sheung Wan Stormwater Pumping Station (SWSPS). It was found necessary to first install an excavation and later support (ELS) system because the pile caps of the pumping station were found at various depths, with the lowest one, the pile cap for the underground storage tank, which also served as base slab of the tank, founding at some 11 m below the existing ground surface. The reclaimed for the pumping station was just 11 m from the harbour. The heterogeneous nature of the dumped fill forming the reclamation, the proximity to the vertical sea wall, the constant recharge from the sea, the proximity of Water Supplies Department’s Sheung Wan Salt Water Pumping Station, all proved to be challenges for the design and construction of foundation and excavation for the proposed SWSPS. I was fortunate enough to be associated with the design engineers for the ELS and supervision of the construction works. The proposed SWSPS’s footprint area measured 56 m long and 43 m wide whereas the ground level was +4 m PD. The SWSPS was surrounded by the various structures sensitive to the ground movement. The sea wall constructed in 1976 was made of modular mass concrete blocks and founded on the submerged bund formed by sand and rock fills. On the west of SWSPS’ proposed location, lay the above mentioned salt water pumping station (SWPS) The SWPS’ foundation had been on the raft footing and the SWPS had a deep culvert on the side touching the proposed SWSPS. On the southern boundary of the Chung Kong Road where the SWSPS was to be located there were major utility pipes and on the opposite side was a police station founded on the piles. It was approximately 20 m from the SWSPS site boundary. The eastern side was an open space meant for site offices and material storage. Prior to the construction, there was an open bazaar and parking space at the site proposed for SWSPS. The ground conditions according to the geological survey map the site was underlain by fill material generally reclaimed in 1982 which probably lay over the medium grained granite formed in the Jurassic-Cretaceous period of Mesozoic area. The ground investigation for the project revealed that superficial deposits comprising fill, marine deposits and alluvium were overlaying the weathered granite with saprolitic zone before reaching the rockhead of strong moderately to slightly decomposed granite. The following figure depicts the typical geological section across the site. Excavation & lateral support system At the outset of the design of the excavation and lateral support (ELS) structures, the complex ground conditions of the site, which had major influences on the selection of the retaining wall system, was fully recognized. The proposed ELS had to be simple and economical, and be able to Read More