You are required to build up the net cost unit rates

for work items in a bill of quantities from first principles.

(a) 

Explain how to build up net cost unit

rate from first principles. (2%)

(b) 

Estimate the net cost unit rates for

following work items and calculate the total net cost of these items. (NB: Show

all calculations, 20%)

Additional

information:

Materials

(supply only delivered to site):

Common bricks

(230 x 110 x 76) $ 1,200.00/1000

Face bricks

(230 x 110 x 76) $ 1,400.00/1000

Cement

$ 12.50/bag; Sand $ 120.00/t;

Dry material for mortar required for 110mm thick brick

walls: allow 3 bags of cement, 3.2 bags of lime and 0.70t of sand

Dry material for mortar required for 76mm think edge

walls: allow 2.4 bags

cement, 2.6 bags lime, and 0.55t of sand

Yellow

oxide $ 40.00/kg; allow 4kg per 1000 standard bricks laid

Allow 10%

wastage on face brick and mortar, 5% wastage on common brick

Subcontract

labour rates:

Common

brickwork $ 2,100.00/1000

Face brickwork

$ 2,300.00/1000

Make no

allowance for attendance and supervision of subcontractor (included in

preliminaries)

Plant:

Cement mixer

hire $ 85.00/day

Make no

allowance for scaffolding, included in preliminaries

All further

information is to be assumed