Methods Of Approximate Estimating, Tendering Procedures, And Contractor Vetting

Compare and contrast three methods of approximate estimating with reference to suitable examples where the methods can be used.

Discuss which Form of Tendering procedure that would be the most suitable for this project.

Investigate the procedures you would adopt, as ‘The Clients Architect’, to vet the suitability of a contractor to tender for and, if selected, manage and construct the development.

• From the drawing, take-off all the relevant dimensions and along with the correct descriptions, document manually on dimension paper (to NRM2).  Include Substructure up to and including dpc,  dpm, hard-core, sand blinding, insulation and floor slab (omit the floor screed)

From the site plan enclosed, consider how many bungalows are the same as the one you have measured. Provide several examples with a brief overview on how the taking off process could be simplified if you were measuring all the properties that were all identical in size.

• Abstract the quantities from your take off in question 2b and produce a bill of quantities (unpriced) ready to be sent out to tender to prospective contractors

• Design a programme in the form of Gantt chart for the substructure    using Excel. (One plot only) Include site set up levelling and landscaping and boundary fencing for this project. Show clearly any activities you believe may extend the duration of the project if they run late.

Three Methods of Approximate Estimating

Approximate estimates are done so as to determine the approximate cost of a structure, within a short term period just before commencing construction works. The estimate is made before final specifications can be selected and the project designed (Sears, 2015). Three methods of approximate estimate include;

Square/ Plinth Area method

This is an approximate estimate method where the price of a square meter area in a building is selected and used as the basis for making the estimate.  The square meter method is mostly used in calculating the cost of buildings such as residential houses, office buildings, hospitals, school buildings, and apartments or flat type of buildings (Collins, 2011). The square meter method of approximate estimating is considered the best method in computing new buildings costs.  In making estimates for multiple storied buildings, the following assumptions are made during the estimation;

The cost of all floors with a basement and a roof, for a one square meter area, are assumed to be in equal costs

• The basement cost constitutes 60% of the floor costs
• The roof cost is 40% of the floors costs (Jha, 2015)

This method of approximate estimating provides results that are more exact when compared to the square meter method.  When this method is being, some assumptions also hold true for buildings with multiple stories;

• The costs of all floors for a one cubic meter area are equal
• The basement costs 60% of all the different floors’ costs
• The volume formula is used in determining the floor volume using the relationship

Volume = Area x Height of a single floor

For the ground floor, the floor height is computed from the middle of the parapet to the top of the footing. For the first floor, the floor height is computed from the middle of the parapet to the ground roof top. For other floors, floor height is computed from each floor to the next (Young & Loomis, 2015).

This method is sometimes referred to as the provisional or the notational bill of quantities: it is used for approximate estimations in projects in which a firm BOQ (bill of quantities) cannot be prepared during tendering time.  The method is used where the design for the building is relatively complete, but either the time or the available information is insufficient to make an exact determination of quantities. This method can as well be used during the design process as a way to control the costs of design.  This estimation is effectively a priced estimation of all the BOQs (Williams, 2016). The method uses drawings to attempt to measure the defined quantities. This method gives a picture of cost distribution that is more accurate. It helps draw designers’ attention to the standard and the non-standard elements of the design, which would consequently be more expensive. It is done by establishing the measurement unit for the group then all the associated bill items is listed in a way that they can be mapped on to the foundations by length.  The bill items are then converted into per meter costs (Lee, Willis & Trench, 2014)

1. Best Tendering Method

Suitable Form of Tendering Procedure

Tendering is the method by which potential suppliers and service providers are invited to supply either goods or services, or both. The key to achieving competitive prices for the project is comprehensive tendering. The tender process starts by putting down in writing what is needed for the project and need to include the specifications for the building, drawings, and requirements for performance, permissions and the legislative framework (these include building control, permits, planning). The tender also needs to have time scales/ schedule, and a way for their procurement. For proper project planning, the contractors require a framework for job costing, time scale for pricing the work, the legislative framework, and the commercial incentive to undertake the works. After making these considerations, the project owner or project manager invites possible providers to tender (Finch, 2011). The invitation to tender for this project should require a PQQ (pre-qualification questionnaire) to be completed by would be service providers. This will enable a shortlist of suppliers to be created: these suppliers’ are most likely to be the best suited for the job and are then invited to tender. This will enhance efficiency in tendering and minimize wasted effort by both parties.

The next step is to invite the shortlisted potential suppliers to tender through an invitation to tender document. The invitation to tender should include the following;

• An invitation letter for tendering
• The form of the tender

Preliminaries that include waste management plan for the site and pre-construction information

The form of the contract, amendments, and conditions for the contract; this will include a model that will allow for amendments to be made if approaches like BIM (Building Information Modeling) will be used so that BIM protocol becomes a part and parcel of the contract documentation

• Information requirements for the employer if BIM is incorporated into the project
• A document for tender pricing; this will be a contract sum analysis of the design and build project.
• A schedule of drawings
• Design drawings for the building, and possible a building information model of an existing building
• Specifications for the works

The tender documents will be broken into a series of work packages, even if a single contractor will handle all the works; each (the packages) having its own specifications and design drawings for the contractor (and/ or sub-contractors) to issue. This will ensure it is easy to price the tender and make comparisons with other parties tendering for the project. This is important for this particular project to make sure the interfaces between work packages are identified properly and clearly allocated to a single package or a group of packages. When there are many work packages, the interfaces are also increased; leading to an increase in possible problems, so the work packages will be minimized.  The pre tender cost plan will be assembled for every works package so the received tenders are easy to appraise (‘Design Buildings UK,’ 2018).

Procedures for Vetting a Contractor

Interviews mid-tender will be done to enable matters be clarified: this will ensure there is no chance for an inaccurate tender to be submitted. Further, the clarification will give the project manager or project owner possible problems and challenges as well as opportunities as described by the tender document. In case any queries were raised by either party during the tendering process, clarifications will be made at this stage, and any amendments to the tender documents made (this can lead to the tender period being extended). The clarification phase will be important to allow for opportunities to be investigated and problems clarified. The result will be a better prepared tender that gives greater value for money and will also save money and time at a later period, especially during project execution (Adriaanse, 2016). Any clarifications and changes, as well as additional information to tender documents will be circulated to all tenderers for creating a level playing field and getting the best contractor and deal. Care will however be taken not to give away any information presented by any of the interested bidders.

The invited tenders will then submit their bids, including the prices for providing goods and/ or services, the time, and how they will meet the project owners’ requirements.  The submissions will include the following;

Tender return slip with information on the return address, the contract details (number), and a checklist

• A completed document for tender pricing
• The schedule of rates
• A plan of the initial construction phase
• Method statements and design proposals that may be requested for
• A program of activities for the project
• Procedures to be used for procurement and management of costs
• An execution plan if BIM will be incorporated into the project
• The main personnel for the project
• Prior experience of the tenderer
• The labor and plant resources, as well as their availability
• The management organization for the project
• Relevant references
• Variant bids

Where the tenderers believe they have a proposal that will provide greater value for money, they can submit a variant bid, which is a proposal that does not comply with the specifications laid out in the tender documents. The submitted tenders will then be appraised and graded, for instance, using a weighted scoring system, and the most qualified tenderer with the highest score be awarded the contract (Adriaanse, 2016).

Settlement

Once the qualified bidder is identified and informed, a tender settlement meeting is held and the parties enter into detailed negotiations. Any further adjustments are then made

This will entail the final agreed form of contract to be prepared (contract engrossment), with relevant appendices and schedules attached to enable its execution. The agreed contract is then signed as a way of executing the contract, with binding terms for both parties (Lim, 2016).

1. Vetting Contractors and Service Providers for the project

This can be tricky; however, using suitable approaches can result in positive outcomes. The first step is to determine if the contractors are transaction based or relationship based, and these can be identified right from the clarification phase. Transactional based contractors use adversarial contract terms and focus more on the transaction and are likely to manipulate terms for their own benefit. These should be differentiated from relationship based contractors: these communicate openly about the contract terms and expectations of the project. The key is to single out the relationship based contractors, and this requires gut feeling, experience, and an understanding of people (psychology). The next phase entails technical; the contractor should be vetted for their contract execution plans. A detailed project execution plan preferably based on project management techniques and tools will be looked for.  The detailed plan will ensure there will be no halts or delays during the execution of the project: a project with a critical path will ensure there is detailed cover for project scope, works, specifications, crew, safety checks, and task broken down for every different craft, such as plumbing and structural engineering (Wilkinson,  Sayce,  & Christensen,  2015).

The contractor must have credentials, with a verifiable track record in executing similar projects: The tradesmen the contractor will use must be vetted to have the requisite qualifications, experience, and certifications from relevant authorities. The smoothness of the construction works, with all specifications being met depends largely on the skills of the workers and tradesmen involved in the construction work.  The technical disciplines must have credentials, governed by bodies that are publicly recognized. Based on this information, judgment will be made on the work ethics of the contractor in general, and background checks with industry insiders and/ or past clients will be very beneficial in determining the contractors’ credentials (Belek, 2018).

The equipment and facilities to be used by the contractor must also be investigated; the right equipment, materials, and facilities are crucial for successful project delivery.  If a contractor has the right equipment and tools, the result can be substantial savings in the construction cost.  Apart from having the right tools and equipment, access to them and their mechanical soundness state must be assessed to ensure they are ready for action and will help the project be executed within the scheduled time.  Technicians, for instance, should not spend time ‘looking for tools’, such will lead to delays and failure to execute the project within the stipulated time (Belek, 2018).

The contractor should then be vetted for safety and health at the workplace (construction site): the contractor must have a functional and up to date work place health and safety (WHS) policy, and have someone assigned to be in charge of WHS. Their track record in past contracts will also be investigated as part of the background check for any incidents. Insurance for workers must be verified, so as to not incur liability and unnecessary delays should there be incidents.

Contingency plans will also be evaluated; these should include alternative suppliers especially for spare parts for equipment and materials to be used in the construction project. These measures will ensure the contractor is vetted on ability to perform: this is then followed by an evaluation of their pricing for the works in order to have the best value for money.  The various areas should be weighted as each carries a different level of importance and used in scoring to classify the contractors.

Q 2 The takeoff list is shown in the table below;

First, using the square area method, the floor area is calculated (Done in MS Excel). Based on NRM 2 rules, the excavation costs are computed, as well as the costs of removing soil in the process of getting the right depth (based on the plans, this is 150 mm deep.  The slab according to NRM 2 specifications and relevant building codes will be 100mm thick, with the sand blinder being 50 mm thick.

The taking off process is the process by which technical drawings as well as specifications for a building are analyzed in order to identify the required elements. From this, a list of the requisite materials is developed to include each and every building material that will be required, starting with the smallest to the largest component. The measurement of the Take Off process is simultaneous to the RICS NRM 2 (New Rules of measurement), which is a code book detailing the specifications and method of measuring each and every element.  The first process is therefore to determine the measurements based on the NRM 2 standards for measurements. The second process entails preparing the Bill being prepared (of the BOQ); the first step in preparing the bill is to calculate the volumes and areas for the elements and materials detailed in the first step. This entails dimension squaring to compute accurate areas from the resulting lengths. The volumes are then generated based on the squaring, such as for the slab. This is followed by abstracting, where the squared dimensions and descriptions are entered into an abstract and written in an order that is recognized ready for billing purposes. The next phase is Billing, where all the items are collected and presented in a bill order that is recognized.  All the components needed for the complete building are listed in appropriate work-section headings to give the item description and the recognized measurement units.  When there are several buildings that are similar to the drawn Bungalow, a basic method for making the taking off process simple would be to get the measurements for a single building and then obtain the necessary measurements for area and volume, and generate the Bill. The values are then multiplied by the number of buildings. For instance, the floor area for the bungalow is 161.82 m². So if there are 23 similar bungalows, then the total area used for the Bill becomes (161.82 x 23) m2. Alternatively, because of the increased use of BIM in construction planning, the process for takeoff can be further simplified to help avoid manual computations.  With BIM, all the dimensions of the building are set in place during the architectural and design phase; the structural engineering and design phase also puts in the requisite dimensions and standards for the buildings. Further, the BIM will have links to suppliers of the specific materials for the takeoff; the quantity surveyor, armed with dimension and elevation details for the entire site will have all this information and so will just extract the required measurements from the BIM data files, make any adjustments, and because the materials are linked to suppliers, with details of product specifications, quality standards, price, warranties, and even expected life span, the quantity surveyor will easily obtain the takeoff list and detailed prices, together with the construction schedule. This will help place orders based on the schedule so that the just in time principle is used to schedule deliveries, for efficient works.

Q 3 a.  The schedule of rates for the takeoff list is shown in the Table below, with costs (and the links to the sources)

References

Adriaanse, J. (2016). Construction Contract Law. Basingstoke : Palgrave Macmillan

Belek, J. (2018). 8 Steps to Vet Construction Subcontractors - SRFM. [online] SRFM. Available at: https://srfm.com/business-insurance/8-steps-to-vet-construction-subcontractors/ [Accessed 24 Mar. 2018].

Collins, R. J. (2011). Project management. New York, Nova Science Publishers

'Design Buildings UK' (2018). Tender processes for construction contracts - Designing Buildings Wiki. [online] Designingbuildings.co.uk. Available at: https://www.designingbuildings.co.uk/wiki/Tender_processes_for_construction_contracts [Accessed 24 Mar. 2018].

Finch, R. (2011). NBS guide to tendering: for construction projects. London, NBS.

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Jha, K. N. (2015). Construction Project Management: Theory and Practices. [S.L.], Pearson Education India.

Lee, S. J., Willis, A., & Trench, W. (2014). Willis's elements of quantity surveying. Chichester, West Sussex, United Kingdom : Wiley/Blackwell

LIM, P. (2016). Contract administration and procurement in the Singapore construction industry. Hackensack, New Jersey : World ScientificBottom of Form

Sears, S. K. (2015). Construction project management: a practical guide to field construction management. Hoboken, New Jersey : Wiley

Williams, P. (2016). Managing measurement risk in building and civil engineering. Chichester, West Sussex, United Kingdom : Wiley Blackwell

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Wilkinson, S., Sayce, S., & Christensen, P. H. (2015). Developing property sustainably. London, Routledge. Bottom of Form

Young, R. A., & Loomis, J. B. (2014). Determining the economic value of water concepts and methods. Abingdon, Oxon: RFF Press