Estimating Methods

Question 1

What are the two methods of single rate estimating?

Answer 1

Functional unit of accommodation
Floor area

Question 2

Explain functional unit of accommodation

Answer 2

The number of units is counted ( e.g the number of occupants or main furniture objects ) this number is then multiplied by the cost per unit. This data will then provide a total estimated cost.

Question 3

What is the formula for functional unit of accommodation?

Answer 3

Number of units x cost range ( per unit ) = total cost

Question 4

Name 3 advantages of functional unit of accommodation

Answer 4

Any 3 of the following:
Quick and simple
Can be done without drawings and specifications
No take-off needed
Useful for buildings where standard size units occupy it

Question 5

Name 3 disadvantages of functional unit of accommodation

Answer 5

Unreliable
Large deviation from accurate value
It is not based on drawings or specifications

Question 6

What is floor area estimating?

Answer 6

The floor area of the proposed building is measured at each floor level. This method is ideal for early budgeting purposes

Question 7

What is the formula for floor area estimating?

Answer 7

Floor area x cost range = total cost

Question 8

Name 3 advantages of floor area estimating

Answer 8

Any 3 from the following:
Quick method
Easy to employ, as rules for calculations are simpler
Directly relates to accommodation
Allows comparison of different designs
Meaningful to both client and architect as it uses m2
Allows comparison between buildings that differ in shape and size

Question 9

Name 1 disadvantage of floor area estimating

Answer 9

Fails to take account of any variation in the plan, shape or stored height

Question 10

What are the 3 methods of multiple rate estimating?

Answer 10

Elemental cost planning
Approximate estimating
Bill of quantities

Question 11

What is elemental cost planning estimating? Including the 2 methods

Answer 11

The proposed building is split into a series of elements. E.g foundations, walls, roof etc. the two methods are;
Approximate quantity of each element, unit rate
Using the total cost of a similar building, and applying it to the measure of the new building

Question 12

What procurement method is elemental cost planning usually used for?

Answer 12

Design and build

Question 13

Name 3 advantages of elemental cost planning estimating

Answer 13

Easy to understand
More accurate
Good for cost planning

Question 14

Name 1 disadvantage of elemental cost planning estimating

Answer 14

More work and effort is required in preparing this method

Question 15

Name 3 ways of selecting and using cost data

Answer 15

Any 3 from the following:
Using own historical data
National historical data
Price books (SPONS & BCIS)
Specialist sub-contractors, quotes etc
Building magazines
Websites

Question 16

Why is using your own historical data the mos preferred method of selecting and using cost data?

Answer 16

As adjustments would have already been made such as;
Location
Inflation
Preliminaries etc