Road Unit Rate Development

To determine if the unit rates for roads used in 2008 information were still appropriate as at July 1 2010, costing information from 3 large subdivisions constructed in 2009/2010 was considered.
A cost based on the 2008 unit rates and known quantities was calculated, and compared to the overall cost of road works for the subdivision. The overall percentage difference between the calculated and actual costs was 13%, but the variation between subdivisions was very pronounced, with the total cost of the Edam Grove being much lower than the calculated value, and the cost of Jealous Road being 29% higher.

A check of the Queensland Office of Economic and Statistical Research Asset Revaluation Index page shows that in Queensland the average cost of construction dropped by about 3% in the period March 2008 to June 2010.

Given the significant fluctuations between subdivisions it is difficult to pinpoint a typical rate, but averaging the average increase in sub-divisional works (+13%) and the change in the Asset Revaluation Index (-3%) gives +5%, which is still well inside the range of sub-divisional figures.

Bargara Views

Quantity Units 2008 Rate Calculated Cost Actual Cost Percentage Difference
Pavement Area 4,941 sq.m $75.26 $371,859.66
Footpath Area 652.8 sq.m $74.58 $48,685.82
Kerb Length 1,291 m $62.66 $80,894.06
Total Replacement Cost $501,439.54 $582,814.10 16%

Jealous Road

Quantity Units 2008 Rate Calculated Cost Actual Cost Percentage Difference
Pavement Area 6,185 sq.m $75.26 $465,483.10
Footpath Area 365 sq.m $74.58 $27,221.70
Kerb Length 1,226 m $62.66 $76,821.16
Total Replacement Cost $569,525.96 $734,451.00 29%

Edam Grove

Quantity Units 2008 Rate Calculated Cost Actual Cost Percentage Difference
Pavement Area 2147 sq.m $75.26 $161,583.22
Footpath Area 0 sq.m $74.58 $0
Kerb Length 480.4 m $62.66 $30,101.86
Total Replacement Cost $191,685.08 $107,648.00 -44%

Overall

Quantity Units 2008 Rate Calculated Cost Actual Cost Percentage Difference
Total Replacement Cost $1,262,650.59 1,424,913.10 13%

Sub-divisional Data

  1. Spreadsheet 1
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