Case study questions Flashcards
What does value engineering mean to you?
Value engineering is used to solve problems and identify and eliminate unwanted costs, while improving function and quality. The aim is to increase the value of products, satisfying the product’s performance requirements at the lowest possible cost. This might mean using a different material which is lower cost but provides the same function. Sometimes it is used as an excuse for cutting costs which can impact on quality, this is the reason it received negative press in the Hackitt Report in relation to cladding in Grenfell tower.
Can you provide any examples of the value engineering carried out?
For example just taking the Ubn Building – I originally worked with the contractor to incorporate an area of the lobby in the LL space into the demise as a reception area as it was a deadspace area with full height curtain walling. When the costs came in however we were tipped over budget so unfortunately this space had to go as it added an extra £25000 to the cost due to the partitioning, changes to AC and lighting required. I decided to remove it, and focus on improving the main area being leased instead, the other issue was it might start tenants on other floors asking to use this space. It also created a narrow pinch point after reception so I think the design was improved without this area being enclosed as there was more ‘wow’ factor on entrance to the unit as a large open plan reception. As a compromise I put seating in the lobby instead so it could still be used as informal meet and greet area or for people to sit and admire the view.
Can you tell me the main types of AC in a building?
VAV (Variable air volume) VRF (Variable Refrigerant Flow) AKA VRV (DAIKIN) 2 pipe, 3 pipe, 4 pipe. Chilled beam Split systems
Describe a VRF system?
What are the advantages and disadvantages of such a system?
VRF (Variable Refrigerant Flow) is a system which provides HVAC to a building.
- Inside the office there are grilles within the ceiling (or could be exposed) which are conencted to evaporator units which are usually fancoil units.
- The fancoil units are connected to an external heat echanger or condenser unit.
- The flow of refrigerant to each fancoil is adjusted depending on the local demand at the controls.
- 2 pipe – provide either heating or cooling but not simultaneously
- 3 or 4 pipe can provide heating some zones and cooling others simultaneously
- Heat recovery allows heat recovery from zones being cooling to be used in those being heated.
- Fresh air can also be ducted in or they can just recirculate.
- Advantage – local controls good for lots of compartments, simultaneous cooling/heating demand, doesn’t take up much space so can be retrofitted.
- Disadvantage - can be noisy/vibrate as fans are witjhin the occupied space.
Described a VAV system?
- VAV stands for variable air volume
- Air handling units (AHU) supply air through ductwork at a controlled pressure and the temperature of the space is moderated by adjusting the supply flow.
- This is achieved by a series of thermostatically controlled dampers.
- The AHU can have heating/cooling units within or they can be connected up to the buildings boilers or chillers
- The AHU also mix fresh air with recirculated air.
- Controlled locally or by BMS.
What are Chillers?
- Chillers are used in buildings to provide cooling.
- This is typically for heating, ventilation and air conditioning (HVAC) systems providing thermal comfort for occupants.
- They can be:
- Air cooling, which rejects heat to the outside air by circulating it through the condenser. E.g. the dry air coolers at Aus House.
- Evaporative cooing, which uses the addition of a water mist to the air to enhance the cooing effect.
- Water cooling, which is generally suited to large systems and requires connection to cooling towers E.g. Exchange House
- Chilled water can be supplied direct to units such as ceiling mounted chilled beams.
How did you deal with corona virus during your basinghall Street fit out
We wer about 2 weeks away from finishing the job when lock down occured at the end of March. The next morning the managing agent for the building rang me up and said why are there personelle on site this isnt essential works, we want to close the building down and we cannot do this with contractors still on site. So the contractors had to left. The government information was sketch at this time, the lines were blurred between I called the client to discuss, I advised them that a pandemic cluld be considered as a force majeure event. I advised them of the possibility to suspend the works but that both parties would have the mutual right to terminate after two months under the contract unless an alteranive agremenet was put in place. The options avaialble were
- Suspension
- Extention of time
- Clause 2.26.14 of JCT Design and Build 2016 Edition refers to force majeure as one of the Relevant Events entitling the contractor to a fair and reasonable extension of time for completion of the works (albeit no entitlement to additional payment). No further definition of what constitutes a force majeure event is however provided and there is room for debate as to whether the current situation falls within the ambit.
- Termination
- In particular, clause 8.11.1 of the JCT Design and Build contract allows either party to terminate the contractor’s employment under the building contract as a result of force majeure.
- Work must have been suspended for the relevant period stated in the Contract Particulars beforehand; the JCT default position being two months.
- Frustration - common law solution ends contract neither at fault. client wants contract to continue also courts take a dim view where other actions available.
The JCT 2016 Design & Build standard form lists force majeure as a Relevant Event therefore enabling the Contractor to claim an extension of time, if it can show that works were delayed as a result of such an event. However, it is not a Relevant Matter and so the Contractor would not be able to claim loss and expense.
Under clause section 8 of the contract - maximium period of suspension was 2 months under the contract particulars after which time either party could terminate the conctract (8.9.2). Force Majeure. Issued a letter of suspension. Fortuantely the works were only suspended for 1 month and are back onsite now. Could have issued a letter of extention of time citing force majeure as a relevant event nbut concerns over claims for loss and expense and preliminaries.
What is two stage tendering and why didnt you consider it for your projecct.
Why didnt I use it?
Two stage tendering is often used with Design and build contracts however:
- Costs of the first stage PCSA would have added to the overall amount - strict budget limitations.
- Although it might have assisted in demonstration of value for money, in the second stage it is still negotiated.
- Time - tendering in the first stage would have been slower than the route I chose.
- Employer has some design responsibility at stage 1, made sense where using a contractor with inhouse design team for the risks to be bourne entierly by the contractor. There must be enough of a design at stage 1 to allow for firm preliminaries and a programme from the contractor, otherwise these may require re-negotiation at second stage.
WHAT
- The contractor is appointed at a much earlier stage in the construction process than would normally be the case, but on a provisional basis, using a Pre-Construction Services Agreement (“PCSA”)
- They agree to undertake pre-construction services effectively as a consultant, with the intention that the parties will ultimately enter into a lump-sum or a cost-reimbursable contract with a target price following a period of negotiation.
- Competetive tender based on an outline scope of work/incomplete drawings with an outline price and programme for the works.
- stage 1 tenderers include
- proposed construction programme
- method statement
- price for preliminaries
- percentage for overheads and profit
- competitive tendering of some already defined work packages
- lump sum or cost reimbursable price for pre-construction services and design fees.
- sub-contractor procurement programme
Second stage Tender
- Sucessful tenderer/preferred contractor is in extended contract negotiation with the employer.
- The negotiations run in parallel with the works which the contractor is carrying out under the PCSA.
- The process relies on a certain amount of cooperation between the parties to be successful.
- Typically, the type of issues on which the contractor will advise the employer will include the buildability of the design, based on his experience.
- The contractor will also be seeking to agree a programme and cost plan with the employer.
- The contractor may also tender early and long-lead works packages, and together with the employer select certain specialist sub-contractors.
- Tendering may be on an open-book basis to allow the employer to monitor and understand the contractor’s pricing.
- Stage 2 concludes with agreement of a lump sum price for completion of the project and the terms of the building contract.
- Theoretically, the employer may appoint an entirely different contractor to carry out the construction works under the building contract.
- However in practice, the employer and stage 1 contractor will usually have worked closely together during the initial stage, enabling them to reach an agreement as to the price and terms of the contract.
- Given the contractor’s involvement in the development of the design, the building contract will generally be a design and build contract
PRO
- This method of procurement is often used when an employer wants a project to start as soon as possible. Achieving early appointment of the contractor, prior to completion of the design, potentially leads to an earlier start on site which may mean earlier completion.
- Other methods of procuring construction works quickly, such as construction management, do not provide the certainty of price which can be achieved with two stage tendering.
- the main contractor positively contributes to the schedule, design, buildability and logistics during the second stage, in collaboration with the employer’s team leading to fewer problems during construction
- The contractor can start developing solutions to problems which it is anticipated may arise during construction; this may lead to a shorter construction programme.
- Good for complex projects
CON
- The employer pays an additional fee for the contractor to carry out the pre-construction services. This fee is not incurred where a single stage tender process is used.
- Once the preferred contractor is appointed, it is no longer in direct price competition with other bidders. This means that there is no particular incentive on the contractor to provide a good price, so other methods will have to be considered in order to insure the pricing represents value for money.
- If the parties fail to adopt a co-operative approach, the second stage can be difficult for the employer as the contractor is in a strong negotiating position, being already committed to the project.
In stage 2, due to the absence of any direct price competition from other bidders, the contractor may seek a greater allowance for risk transfer.
Use of a Guaranteed Maximum Price (“GMP”) for the building contract may address some of the pricing issues, but unless on an open book basis may include a healthy margin to allow the contractor to realise a gain.
- Rigorous prequalification selection - understand supplier’s real time capability and capacity
WHAT IF THE EMPLOYER AND CONTRACTOR ARE UNABLE TO REACH AGREEMENT AS TO PRICE?
- In order to give the employer options at the end of stage 2, the PCSA used to appoint the contractor should provide a mechanism for the employer to explore other options if the contractor does not submit a favourable bid. One option is for the employer to indicate a price ceiling that the stage 2 bid must not exceed. If the ceiling is exceeded, then the employer should have the right to return to market on the basis of either a conventional single stage tender, or a package based procurement.
How did you select the contractors for your project?
- As I had chosen the design and build procurement route I searched out contractors who had a strong inhouse design team
- I wanted a contractor who had a proven track record of delivering design and build projects to a good standard on time and in budget.
- Also wanted a contractor who could work collaboratively with me as the Employer’s agent (some contractors take an advarsarial approach).
- I spoke to various directors in my department and obtained names of contractors who had worked sucessfully on projects with them, I was able to review cost data from these projects for comparison from our project files.
- I used the information to narrow down to a list of 4 and then I spoke to the contractors over the phone to discuss the projects and understand their availability.
Are you aware of the mistake you made when describing the AC?
Yes it’s really frustrating ad embarrasing as I normally have excellent attention to detail but it was a copy and paste error, I am very aware of the of the differences between VRF and fancoils.
- valpy had chilled beam
- one station square and berkshire house both had 3 pipe VRF systems
- The urban building was actually a 4 pipe fan coil system
- A fan coil is a has a filter, fan, heating coil and cooling coil which delivers recirculated air at the appropriate temperature.
- Each fan coil is connected to a low temperature hot water (LTHW) system for heating and a chilled water (CHW) system for cooling, which are both fed from central plant.
- Ventilation is usually provided by a separate fresh air supply and extract systems fed from central air-handling plant.
- 4 pipe can simultaenous cool and heat various zones whereas a two pipe can only do one or the other
- VRF on the other hand uses a similar type of terminal unit, consisting of a filter, fan and a single, refrigerant-filled heating/cooling coil.
- The fan coil units (‘indoor units’) are linked together by a network of refrigerant pipes and connected to an outdoor unit which exchanges heat with the outside air as required
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What is CAT B versus CAT A?
What buildig regulations did you consider for your project?
- Approved Document L2B: Conservation of fuel and power in existing buildings other than dwellings
- for the lighting and the secondary glazing.
- I also used a
- Cibsey guidance
- an M and E consultant
- Non domestic building services compliance guide which helps meet L2B
- L1B stipulated lowE glass for secondary glazing Low-E glass has a hard metallic coating on the surface facing the cavity, which significantly helps with heat containment.
- Also the U value was to achiveve 1.2 W/m2. K (Watts per metre squared Kelvin.
- also stipulated weather stripping to avoid condensation build up between the panes.
Why would you use a 4 pipe fancoil system over a 3 pipe VRF system?
SAFETY -
SUSTAINABILITY
Refrigerants have a high global warming potential (GWP) - Some such as R22 are banned.
COSTS
- F-Gas regulations require either frequent inspection of pipework joints or a leakage detection system, both of which can be a bit costly. In comparison, chilled water systems use an inert liquid which removes the need for these additional requirements.
Chilled water still requires refrigerant in the main plant but it is less of it and it is not having to be pumped all around the building creating more leaks.
Building size restrictions
What are the employers requirements?
- The employer’s requirements are a set of instructions that the employer provides to the contractor setting out the standards that are to be satisfied when designing and constructing the building.
- As the employer’s requirements will be the primary document of reference it is important that this document is as complete as possible at the point of tender.
- It is the responsibility of the employer’s agent to check that the employer’s requirements typically cover the following:
- SITE DETAILS its boundaries,
- PRECONSTRUCTION INFO AND O AND MS any site surveys or reports
- PROJECT DESCRIPTION including any drawings/ specifications already prepared
- PURPOSE for which the building is to be used
- FUNCTION REQUIREMENTS - accomodation to be provided statements of functional requirements, e.g. schematic layouts and/or drawings
- SPECIFIC REQUIREMENTS - QUALITY AND FINISHES inc retaining. as to finishes and any other elements
- bills of quantities (if supplemental provisions apply)
- CONTRACTOR DRAWING REQUIREMENTS DETAILED AND AS BUILTS requirements regarding submission of the contractor’s drawings (if supplemental provisions apply)
- SITE RECORDS requirements regarding records the site manager is to keep (if supplemental provisions apply)
- EMPLOYERS AGENT FUNCTIONS
- functions to be carried out by the employer’s agent and any other members of the employer team
- FORM OF CONTRACT
- ACCESS RESTRICTIONS - site fit out guides confirmation of whether Alternative A (stage payments) or Alternative B (periodic payments) will be used • details of any provisional sums • statement of any planning restraints, e.g. restrictive covenants, and any permissions already granted • access restrictions • availability of public utilities • form of contract and any amendments, and any legal documents • method of presentation of the contractor’s proposals • various other information to be included in the contract, e.g. project control requirements and templates and • any other matters likely to affect the preparation of the contractor’s proposals
- The employer’s requirements should be confirmed prior to execution of the contract as although modifications can be made once the contract is in force, such adjustments are construed as a ‘change’ under clause 5.1.1 (clause 2.12).
- As the contractor is not responsible for either the content of the employer’s requirements or for verifying the adequacy of any design within them (clause 2.11) it is the employer that is liable for the consequences of a ‘change’.
- Design and build contracts do not therefore inherently relieve the employer from ‘all design’; retaining responsibility for any deficiencies in the underlying design. These consequences may include a claim for an extension of time (clauses 2.24; 2.25; 2.26.1) and for loss and/or expense (clause 4.20) by the contractor.
- It is important to note that, under an unamended JCT Design and Build Contract, if the contractor’s proposals are, at a later date, to fall short, or are in any way inconsistent with the employer’s requirements then the contractor’s proposals will prevail, as under the JCT Design and Build Contract, the employer is deemed to have satisfied him or herself (at the time of appointing the contractor) that the contractor’s proposals meet with his or her requirements. In that case, if the employer still required something that the contractor’s proposals do not provide for, then it may be deemed as a ‘change’. However, the conditions are often amended to make the employers requirements take priority, which then aligns the contract to most other design and build contracts.
What is two stage tendering?
TO
