Case Study Flashcards
How did you go about selecting contractors given the nature of the works?
Selective tendering - Contractors were selected from a pre-agreed framework/ approved-suppliers list. Approved contractors list - Contractors put through a formal contractor pre-qualification process. This may be a short interview or perhaps a pre-qualification questionnaire (PQQ) - The aim is to ensure that the proposed contractors have the relevant experience, the relevant financial standing (further financial checks may be necessary) and a suitable health and safety record.
Run through what was included as part of your tender analysis?
Partially quantitative and qualitative factors - I compared the tender sums, ensured they were realistic for the tasks in the specification through comparison with BCIS figures. I compared proposed lead-in times and length of the project. 15 weeks both. Experience of the contractors. The length of time for works proposed. Past performance.
How were the tenders assessed? 100% cost of was there a quality assessment?
Assessments that identify the tender that best meets the client’s needs and offers the best value for money can be more beneficial in the long run. This is sometimes referred to as the ‘most economically advantageous tender’ (MEAT) approach as opposed to the lowest-price approach. The criteria are then weighted to reflect how important they are to the client. It is normal to give price a weighting of at least 60%, with the remaining percentage allocated to the other criteria, giving a total of 100%. It is good practice to make the criteria and weightings known to tenderers in the invitation to tender.
Were there any implications in relation to bats as a result of replacing the roof covering?
No. There were no signs of bats droppings or chattering. If they were present I would arrange for specialist advice
Electrics - how did you allow for electrics to be upgraded within your specification? Was specialist advice sought? If so, how were specialists appointed, and how were their specifications used in conjunction with your spec?
JCT contract had a Contractors design element. Performance item, to meet standards of 18th edition of the ‘Wiring Regulations’, which are published as British Standard 7671. Electrical layout provided in a plan (referenced in spec). Specialist appointed as a sub-contractor by the contractor.
What is selection criteria
Selection criteria (sometimes referred to as award criteria or evaluation criteria) are lists of items against which a prospective supplier can be assessed before a selection is made and a contract awarded. They might also be used to help identify suitable individuals when seeking new employees. Informing applicants what the selection criteria are can create a fairer process, enabling applicants to consider in advance whether they are suitable, and helping them tailor their submissions. It also makes the application process more transparent and so less open to challenge. Price. Relevant experience. Understanding of the requirements. Past performance. Technical skills. Availability. Management skills. Proposed methodology. Compliance with the requirements of the submission process. Financial standing.
Run through what was included as part of your designers risk assessment
Quantitative risk assessment - Severity X Likeliness of risk. Identified who is at risk - Construction Staff. Main risks: Asbestos flue - Licensed removal by specialist. Working at height - Ensure compliance with Working at Height Regulations. Risk of stone slates falling and rot to rafters and general construction site risks - Wear PPE. Moving vehicles on narrow private road. Power tools - training and PPE Silica dust - Cutting bricks outside and wear mask
You gave your client the option of concrete tiles. Were any structural calculations carried out to ensure the building could take the additional load before presenting this option to the Client?
A cost estimate for additional restraint was considered. Structural calculations were not necessary during the initial decision making stage.
You mention that replacement of the heating system was recommended. What system was specified?
A pressurised unvented central heating system served by an oil-fired boiler.
What are the regulations for oil tank?
Part J - Combustion appliances and fuel storage systems The base needs to provide continual structural support, even though ground conditions may vary from season to season. The base should be: • Adequate for the weight of the tank and its contents – 1000 litres of fuel weighs just under a ton; • Non-combustible, imperforate and level; • Constructed of concrete, paving stones or stonework; • Large enough to extend 300mm beyond all sides of the tank. constructed of either a 100mm thick slab of concrete or closely butted paving slabs of minimum 50 mm thick. To protect tanks from an ignition source, tanks should be sited: 1.8m away from non-fire rated eaves of a building 1.8m away from a non-fire rated building or structure (e.g. garden sheds) 1.8m away from openings (such as doors or windows) in a fire rated building or structure (e.g. brick-built house/garage) 1.8m away from liquid fuel appliance flue terminals 760mm away from a non-fire rated boundary, such as a wooden boundary fence 600mm away from screening (e.g. trellis and foliage) that does not form part of the boundary. If it is impossible to comply with the separation distances, then a fire protection barrier (with a minimum 30 minutes fire rating) should be provided. The separation distance required between the tank and the fire barrier should be a minimal 300mm unless a greater distance is specified by the tank manufacturer. It is possible to site a fuel storage tank inside a garage or out-house; however, they need to be self-contained within a 60-minute fire rated chamber.
Were there any alternative, perhaps more sustainable, heating solutions available? Funding?
Ground source heat pump. Air source heat pump. Solar power (Asthetic)
Run through how you went about preparing the detailed schedule of works. What was used to assist?
The building regulations - for oil tank. Best practice guidance including; Lead Sheet Association Guidance for abutment flashing details.
What was included from a sustainability perspective? Did the EPC rating improve?
An EPC consultant assisted with the design and provided the requirements to obtain an E rating. Insulate the roof and provide a new heating system. EPC rating improved from a G rating to an E.
Why didn’t you go to more contractors?
The tenders received were deemed to be accurate during the analysis stage and they were fairly similar. Re-tendering would have required another 4 weeks.
Was a close roof inspection not considered given the state of the slates and timbers prior to tendering?
The client was forwarded about the condition of the Stone Slates. Close up in inspection was offered, but the client asked us to proceed with isolated repairs and assess the condition at this stage.
You mention that the Client only wanted to proceed with patch repairing the roof. How did you stipulate this as part of the specification?
Carefully remove loose damaged stone slates with a slate ripper and secure with new stone slates secured using lead ‘tingles’. Where extensive damage had occurred I proposed stripping and relaying isolated sections replacing stone slates on a like for like basis where required. Copper nails where necessary.
Was your specification prescriptive or performance based? What are the advantages of each?
The spec included a combination of performance and prescriptive specifications. Generally items were specified prescriptively, but items requiring specialist design are specified only by performance (such as service lifts). Prescriptive specifications typically contain detailed descriptions of the following components: - General requirements relating to regulations and standards. - The type of products and materials required. - The execution and installation methods required. Prescriptive specifications give the client much more certainty about the end product when making investment decisions (such as when they appoint the contractor), and place a greater burden on the designer to ensure proper installation rather than the contractor. Performance specifications allow for specialist input in the design.
You mention you identified decay to rafters in the attic room. Run through the repair specified.
Only a small section of rafter was visible upon my inspection. I allowed for a PC sum which could be used depending on circumstances any opening works revealed. We found decay was fairly isolated. All decaying sections were removed and timber splints nailed to both the sides of the existing.
As part of the specification, how did you obtain cost options (i.e. - for full re-roof and patch repair only?)
Included two items within the specification for the contractor to cost.
You mention there was an unstable wall to the rear porch. What did you consider and specify in relation to this? Was advice from a structural engineer needed?
The porch was generally dated and poor. I specified taking down the existing porch from the top down and rebuilding. A PC sum was included for whether any additional works for foundations were necessary. Walls were to be Cavity. uPVC double glazed prefabricated conservatory. These works were omitted as part of the value engineering exercise.
Did you obtain a refurbishment and demolition asbestos survey? Was any further asbestos discovered?
I obtained a refurbishment and demolition survey. An asbestos flue serving the oil fired boiled. Licensed work
Run through how you assessed the Battens?
BS5534:2014 - The changes means that the grading of battens can no longer be done on site. All battens will have to be checked off site to ensure that they conform to the new standard, and there is no longer the option of a “part-graded” batten.
Batten suppliers will claim to be BS 5534 compliant, but they often lack a reputable third-party accreditation.
– One if the biggest issues is with the under-sizing of battens. The update includes a clear tolerance limit for the depth of battens, allowing for 3mm over, but not being less than 25mm deep.
– Marking must be present on all battens to identify the origin, size, suppliers and conformance with BS 5534.
– The appropriate accompanying paperwork must also be included to show the type and method of preservation treatment
You should ensure that you purchase battens from a reputable manufacturer – this should ideally be one with UKAS accreditation. Graded battens should also go through a series of checks, ensuring that knot-configurations and other issues meet the requirement of the standard. If issues arise, they should be reported to the supplier as soon as possible.
Explain what was included in your H&S file?
