Design Evonomics & Cost Planning Flashcards
(20 cards)
Could you explain the key differences between an Order of Cost Estimate and a Formal Cost Plan according to NRM1?
An order of cost estimate is used in the early stages of a construction project, specifically RIBA stage 0 and 1 and will generally be based off limited design information.
A formal cost plan will take an elemental form and will be produced in RIBA stages 2 to 4 and will generally include less assumptions.
How do you calculate and apply construction inflation when preparing cost plans that span multiple years?
I would use BCIS to do this by setting the range from the base date up to the current day.
What are some other types of indices from BCIS?
Cost indices
Trade price indices
Regional price indices
Output price indices
Explain what net to gross ratio and wall to floor ratio mean, and how they influence project costs.
Net to gross ratio is when you divide the NIA by the GIA which demonstrates the efficiency of the internal building design.
A wall to floor ratio divides the total façade area by the floor area which indicates if the buildings envelope is economically designed.
A circular building would be considered to have the most efficient wall to floor ratio, followed by a square and rectangle.
What is considered a good net to gross ratio?
It depends on the building, but typically a good ratio for commercial would be 75% to 85%, residential 75% to 90%, industrial 80% to 95%.
What is considered a good wall to floor ratio?
Generally the lower the ratio the more efficient the building can be considered.
It’s generally agreed that the most efficient building would be a circle, followed by a square and then a rectangle.
What are the main risk categories defined in NRM1, and how do you quantify them in your cost plans?
Design risk
Construction risk
Employer risk
External risk
Operational risk
To quantify these risk I would apply a contingency allowance based on the probability and impact of the risk.
How do you structure an elemental cost plan, and how does this differ from earlier stage cost estimates?
I structure my elemental cost plans by following the guidance set out in NRM1 with the main building elements being,
Substructure
Superstructure
Internal finishes
FF&E
Services
External works
Contractor costs, including preliminaries
Contingencies and risk allowance
An elemental cost plan provides a greater level of detail and breakdown compared to an order of cost estimate which is generally compiled using high level assumptions.
For the 1 James Street project, what specific adjustments did you make to your benchmark data to ensure it was relevant to the client’s Cat A office fit out requirements?
I applied inflation to each element of benchmark data to ensure it was up to current day market rates.
On the River House project, you provided two cost options for the reception layout. What were the key cost drivers that differentiated these options?
The architect provided these two options to give them client different layouts and design for the reception area.
The key cost drivers for this where to consider which option offered the most efficient design, both in terms of cost and in net to gross ratio.
For the Union Street recladding project, you mentioned site constraints including proximity to railway and Underground lines. How did you quantify these constraints in monetary terms without detailed design information?
I applied a percentage allowance to cover the potential cost implications of these constraints.
These constraints were particularly difficult to quantify, therefore referred to inhouse benchmark data where similar constraints had been present and gathered the total cost associated with these risks and worked them back to a percentage.
I then included this in the cost plan.
How do you determine the appropriate level of risk allowance at different RIBA stages?
I will include a risk allowance at all RIBA stages which generally reduces as the RIBA stages advance in line with the design and site information.
I will calculate the risk percentage based on the guidance set out in NRM1.
When benchmarking projects, what specific factors do you consider to ensure the data is comparable and relevant to your current project?
I will input the data into my firms benchmark template which consists of different headings such as,
Sector
Data of CSA
Area
Cost per area
General comments
Additional headings may be included depending on the sector, such as for industrial a cost per unit may be introduced.
How do you effectively communicate cost uncertainties to clients, particularly at early RIBA stages when design information is limited?
I will capture my cost uncertainties within my assumptions and exclusions and note any prominent ones within the Executive Summary.
Additionally, I will always recommend that I present my cost plan to the client, either in person or on a virtual meeting so I can discuss these uncertainties with them.
When a cost plan indicates that a project is over budget, what structured approach do you take to identify and present potential savings options to the client?
I will indicate the items which are a particularly high cost compared to the other elements of the building and compare these to benchmarked data to see if they’re proportionate.
I will then look to arrange a Value Engineering meeting with the relevant design team members to discuss other options.
Once these have been agreed, I will collate a VE schedule, showing the adds and subtracts, and present this to the client.
Scenario: Your client has a fixed budget for an office refurbishment but the design team keeps enhancing the specification. How would you approach this situation and what tools would you use to demonstrate the cost implications?
I would identify the elements which were a significant cost in comparison to the others.
I would then highlight these in my elemental summary of my cost plan.
I may also choose to compare these to benchmark data to consider the accuracy of the rates.
Scenario: You’re asked to prepare a cost plan for a complex project with very limited precedent. How would you build up your costs and what additional contingencies might you include?
I would build up my cost my consulting similar benchmarked projects using both in house and external data.
To quantify my contingencies allowance, I would identify the site abnormals and constraints and apply a risk percentage allowance consulting the guidance set out in NRM1.
Scenario: A project you’re working on has been delayed significantly, affecting your original inflation calculations. How would you recalculate and present the revised cost implications to your client?
When calculating inflation, I would always base this to the construction mid-point.
To work out the revised inflation, I would calculate the works from the construction mid point to the revised completion date.
In your experience moving from RIBA Stage 0 through to Stage 4 on Beckton Gateway, what have you learned about the relationship between design development and cost certainty?
Generally, as the design develops, the certainty of the costs increase as I can reduce my assumptions and exclusions due to unknowns.
However, it is also important to keep in mind the original budget to ensure the design development doesn’t exceed this budget.
Looking back at your experience, what do you consider to be best practice in managing client expectations around costs while still allowing design teams the freedom to develop creative solutions?
Establishing the clients key drivers as early as possible in the project is vital to setting a realistic budget and managing their expectations.
These drivers can then be articulated to the design team so a collaborative approach can be adopted amongst all parties to provide the best outcome for our client, both in terms of specification and commercially.
