Design Economics & Cost Planning Level 1 Flashcards
What is the RIBA Plan of Works 2020?
It organises the process of briefing, designing, constructing and operating building projects into eight stages:
Stage 0 - Strategic Definition
Stage 1 - Preparation & Brief
Stage 2 - Concept Design
Stage 3 - Spatial Co-ordination
Stage 4 - Technical Design
Stage 5 - Manufacturing and Construction
Stage 6 - Handover
Stage 7 - Use
What are the rules under which order of cost estimates and elemental cost plans are produced?
NRM 1 - Order of Cost Estimates and Cost Planning
NRM 3 - Order of Cost Estimating and Cost Planning for Building Maintenance Works
What is an order of cost estimate?
It establishes if a proposed project is affordable and if so, to set a realistic cost limit for the development project
What RIBA Stage is an order of cost estimate typically produced?
RIBA Stage 1 - Preparation & Briefing
What is a cost plan?
Provides an estimate of what the actual project cost is likely to be
Identifies the client’s agreed cost limit and how the money is allocated to different parts of the project
It is a development of the OCE and is based on more detailed design information
What RIBA Stage is a cost plan typically produced?
RIBA Stage 2 - Concept Design
What is the key difference between an order of cost estimate and a cost plan?
An OCE provides a possible cost based on a brief / employer’s requirements within the initial phase of a cost planning process. It is usually completed using cost per m2 or functional units
A cost plan is a more detailed elemental breakdown and reflects how the costs are distributed across the project
What sources of information and cost data are available when preparing an order of estimate or cost plan?
BCIS cost data and information
Published pricing books such as Spon’s
Historic cost data and information from previous projects
In-house cost analysis
Speaking directly with contractors, subcontractors and suppliers for cost information
Existing client information - benchmark data from previous project
How do you adjust costs for time and locaton?
Time - BCIS offers cost indices for the quarter of each year, going back several years and forecasting indices for the expected risk in tender prices. ((forecast for scheme - index) / index) x 100 = % increase in rates
Location - BCIS have a series of location factors to use and adjust Location of cost analysis factor x location of proposed project = new rate
What is the benefit of accurate cost planning?
confirms to the client if the scheme is affordable
places the client in an informed position to make commercial decisions
Acts as a value management tool to ensure the client gets a building which meets their needs, but also represents best value
What is inflation?
NRM 1 defines inflation as an upward movement in average level of prices or costs. Often included as an allowance in OCE’s or CP’s for fluctuations in the basic prices of labour, plant, equipment and materials
What are the 2 types of inflation as defined in NRM1?
Tender inflation - an allocation included in the OCE or CP for fluctuations in prices of labour, plant, materials and equipment during the period from the estimate base date to the date of tender return
Construction inflation - same as above but during the period from date of tender return to mid-point of the construction period
What is life cycle costing (LCC)?
A decision making technique which considers both initial and future costs over the life of a building
It measures and manages lifetime costs and enables design options to be compared from a lifecycle perspective to understand overall costs associated with operating and owning an asset
What is the typical analysis period for LCC?
It should be determined by the client
But it is typically the length of a lease or anticipated functional life of a building or time to first refurbishment
What are the advantages of LCC?
long term value
green building certification credits
reliable planning and reduced risk
What are potential disadvantages of LCC?
Components are not always kept until the end of a buildings life, due to changes in fashion and style for example
Costs associated with defects cannot be predicted
What are the costing considerations for LCC?
Construction -
Planning
Design
Construction
Costs in use - Maintenance Refurbishment Operational Occupancy End of Life
Name some key factors impacting the design economics of a building?
Plan shape - area may stay the same, impacts perimeter and costs associated
Grouping of buildings - cost per unit of external walls decrease
Number of storeys - perimeter length of foundations will be the same as plan shape has not changed, cost of foundations per m2 GIFA is likely to increase due to extra loading imposed, cost implication on walls / partitions/ finishes, heating and air con, structural staircase, staircases or vertical transport
Storey height - volume of building to be heated / ventilated, increase in prices associated with walls because of increased height, structural frame may be more expensive
What is Gross Internal Area (GIA)?
The area of a building measured to the internal face of the perimeter walls at each floor level
What is Net Internal Area (NIA)?
The usable area within a building measure to the internal face of the perimeter walls at each floor level
What is the relevance of wall to floor ratio in design ecnonomics?
it is calculated by dividing the external wall area by the floor area, indicating the proportion of external wall required to enclose a given floor area
Can indicate how efficient a design is - typically the lower the ratio, the more economic the design
Define benchmarking
the use of historical data from projects of a similar nature
can be used as a comparison or check for cost planning purposes
can highlight areas of design that are not value for money, or if the price you have is in line with market conditions
What are the key stages in the benchmarking process?
Data collection
Data comparison
Analysis
Action
Repeat
What factors should be considered when benchmarking?
construction costs and duration
costs / m2 GIA or cost per functional unit
distribution of construction cost
environmental considerations e.g. co2 emissions, energy performance certificate ratings, sustainability ratings
building efficiency (wall to floor ratio)
Timing e.g. is the comparison project costs from FA or contract sum?
Why should projects be adjusted for location where required?
in terms of location, costs can differ for identical projects due to:
- availability of materials, labour and services to the site
- transportation costs and routes
- ease of access
- local labour costs
- travel distances
- existing land conditions
What is the BCIS?
Building Cost Information Service by the RICS
provides cost data on historic projects
can be used to aid in preparation of order of cost estimates and cost plans
How does NRM define the ‘cost limit’?
the maximum expenditure that the employer is prepared to make in relation to the completed building
What is the cost planning process in relation to the RIBA Plan of Works 2020?
Stage 1 - Preparation & Brief:
Order of cost estimate based on either brief or employer’s requirements. Cost information at this stage is rate per functional unit or m2 (GIA or NIA) and can determine the cost limit
Stage 2 - Concept Design
A cost plan can be produced based on design information, providing the overall cost limit allocated to the various elements
Stage 3 - Spatial Co-ordination
As the design develops, the cost plan will be agreed to
Stage 4 - Technical Design
As design develops, elemental cost checks are carried out to confirm the cost plan. Here, the QS can carry out a pre-tender cost analysis as a final check of the cost plan and as a frame for reference when the tenders are returned
Stage 5 - Construction
QS monitors costs and variations and FA
