1. Pre-Contract Cost Control
Cost Plan
Purpose/Function
Assists the design team in controlling the cost of the design
Assists in economically spreading the cost between the elements of the building
A tool for analysing and comparing tenders

2. Cost Planning The process Pre-Contract Cost Control Early cost bracket
information
Detailed Elemental
Cost Estimate
Group Elemental
Outline Cost Plan
Elemental Cost Estimate
adjusted to take account
of coarse elemental
unit quantities
Checked Cost Plan
Adjusted Detailed
Elemental Cost Plan
Adjusted Group
Elemental Outline
Cost Plan
Cost Plan Element allowances
checked with approximate quantities
of specified design information
Historic Group Elemental
Cost analysis adjusted for
Time, Location and
Design Features
Source: Jaggar D. et al (2002) pp 91

3. Cost Plan Pre-Contract Cost Control Group Elements Substructure
Superstructure
Internal/External Finishes
Fittings and furnishings
Services
External works
Preliminaries
Contingencies
Building
sub-total

4. Cost Plan - Detailed Elements Substructure Superstructure
Pre-Contract Cost Control
Cost Plan
- Detailed Elements
Substructure
Works up to the underside of lowest floor finish including damp proof course (dpc)
Superstructure
Frame
Upper floors
Roof
Roof structure
Roof covering
Roof drainage
Rooflights

5. Cost Plan - Detailed Elements Superstructure Pre-Contract Cost Control
Stairs
Stair structure
Stair finishes
Stair balustrades and handrails
External walls
Windows and external doors
Windows
External doors
Internal walls and partitions
Internal doors

6. Cost Plan - Detailed Elements Pre-Contract Cost Control
Internal finishes
Wall finishes
Floor finishes
Ceiling finishes
Fittings and furnishings
Fittings, fixtures and furniture
Soft furniture
Works of art
equipment

7. Cost Plan - Detailed Elements Pre-Contract Cost Control Services
Sanitary appliances
Services equipment
Disposal installations
Internal drainage
Refuse disposal
Water installations
Main water supply
Cold water services
Hot water services
Steam and condensate

8. Cost Plan - Detailed Elements Pre-Contract Cost Control Services
Heat source
Space heating and air treatment
Ventilating systems
Electrical installations
Gas installations
Lift and conveyor installations
Protective installations
Fire fighting, lightening protection
Communication installations

9. Cost Plan - Detailed Elements Pre-Contract Cost Control External works
Site works
Site preparation (clearing, demolition, etc)
Surface treatment (roads, pavements, etc)
Drainage
External services
Water mains
Gas mains
Site lighting, etc
Minor building works
Ancillary buildings
Alterations to existing buildings

10. Cost Plan In developing a Cost Plan it is necessary to adjust for
Pre-Contract Cost Control
Cost Plan
In developing a Cost Plan it is necessary to adjust for
Location
Design features and specifications
Inflation prior to the start using the relevant tender price indices
Projections for future inflation during the construction period
Type of contract and procurement route
Market conditions
A two stage approach
Group elemental outline cost plan
Detailed elemental cost plan

11. Assuming 3.5 m building height
Pre-Contract Cost Control
Design features that can influence building cost
Plan shape
Perimeter to floor area ratio will affect:
cost of external walls per gross floor area
foundation cost per gross floor area
cost of windows per gross floor area
energy cost due to heat loss
cost of cleaning
cost of painting and decoration
cost of service distribution systems e.g. water, electricity, other mechanical systems
100m
50m
200m
Example:
Perimeter = 400m
Floor Area = 10000m2
Perimeter = 500m
Wall-to-floor ratio = 0.14
Wall-to-floor ratio = 0.175
Assuming 3.5 m building height

12. Design features that can influence building cost
Pre-Contract Cost Control
Design features that can influence building cost
Plan shape
Upper floors and Roofs
Larger spans will require
expensive structural roof elements
Load bearing internal walls
Columns to support the upper floors and roof structures
Heavier reinforcement of the upper floors
Complex shapes
Low labour productivity at site
Increased waste of material in terms of cutting waste
Where the ratio of perimeter to gross floor area is higher, the cost of the perimeter elements of the roof will be higher
Reduced level of competition as only contractors specialised in the construction of such a facility can bid for it, hence contractor’s will price higher.

13. Design features that can influence building cost
Pre-Contract Cost Control
Design features that can influence building cost
Internal plan (planning efficiency)
High circulation area to gross floor area ratio implies
Bigger building with higher cost implications
Reduced amount of rentable area if it is a commercial property
Minimising economic viability of the building
Storey height
Has influence and hence cost implications on
Wall to gross floor area ratio
External and internal finishing
Vertical elements of services

14. Design features that can influence building cost
Pre-Contract Cost Control
Design features that can influence building cost
Height (No of storeys)
The cost of some elements will increase while others may decrease. (ref attached extract from Morton R & Jaggar D, 1995, Design and the Economics of Buildings pp )
E.g.
Greater requirement for lifts and stairways
Reduced level of rentable area as a result of bigger stairs and lifts
Increased cost of engineering services
Higher levels of structural stability to withstand wind loads
High levels of life-cycle cost due to maintenance cost of services
Lower foundation cost per gross floor area
Lower roof cost per gross floor area
However the need for high rise buildings despite the cost implications may be due to:
High cost of land in inner cities
Savings in the cost of infrastructure

15. Other features that influence building cost
Pre-Contract Cost Control
Other features that influence building cost
Groupings of building
Closely linked buildings will save on the external works cost
Buildability i.e. the extent to which the design of building facilitates ease of construction
Buildings requiring complex construction methods will therefore be more expensive to build.
Constructional details
Types of Materials used e.g. structural steel or reinforced concrete frame
Site characteristics
Size and topography
Location (accessibility, protection of existing structures, etc)