Useful Life

Click here for a mobile friendly version of this page.

---

The useful life (UL) of an asset is the estimated length of time during which the asset is likely to be able to deliver a satisfactory level of service.

International Infrastructure Management Manual

The International Infrastructure Management Manual states that "useful life" may be expressed as either:

1. The period over which a depreciable asset is expected to be used, or
2. The number of production or similar units (i.e. intervals, cycles) that is expected to be obtained from the asset.

CPA Australia valuation and depreciation guide

The CPA Australia valuation and depreciation guide suggests that there is an asset management/engineering definition of useful life and an accounting one.

1. Engineering Definition - The period from original commissioning to the time of decommissioning, including a number of expected major renewals.
2. Accounting Definition - The period in which the asset is expected to be available for use or the number of production or similar units expected to be obtained by the entity.

General Notes

The useful life of an asset is not necessarily equivalent to its physical life or economic life, a number of other factors may result in an assets useful life being reduced, including:

• Obsolescence
• Changes in community expectations
• Increased demands on capacity
• New legal requirements

Reviewing Asset Useful Lives

Whenever an asset class is revalued the appropriateness of the useful lives applied to the assets within that class should be considered.

Factors that could be considered when reviewing asset useful lives, include:

• The useful lives adopted by other organisations;
• The average condition of assets nearing the end of their expected useful lives;
• The typical design life (with era of construction practices/assumed workmanship/ quality)
• The percentage of assets requiring renewal before reaching the end of their estimated useful lives.

Typical Useful Lives

The useful life of most assets will depend on a wide range of environmental factors, but it is usually necessary to adopt a standard useful life for a range of asset types for asset management and accounting purposes. It would make life much easier if the state or federal governments published a list of default asset useful lives for Councils to use in the absence of better information, but with the notable exception of South Dakota in the United States, a quick internet search seems to suggest that this isn't a high priority for state governments around the world.

The table below is LGAMs attempt to compile a list of realistic asset useful lives.

Asset Type Typical UL Range Asphalt Footpath 30 years 20-50 years Asphalt Overlay 20 years 20-25 years Backhoe 6 years 5-7 years Boardwalk 30 years 25-30 years Boat Ramp 30 years 30 years Bollard 20 years 15-30 years Box Culvert 90 years 80-100 years Brick Paved Footpath 50 years 30-80 years Bridge 80 years 25-100 years Building Envelope 60 years 45-75 years Building Fire Services 40 years Building Fitout 30 years 20-45 years Building Mechanical Services 30 years 25-35 years Bus Shelter 20 years 20-40 years Computer 3 years 3-4 years Concrete Floor 100 years Concrete Footbridge 80 years 25-200 years Concrete Footpath 60 years 20-120 years Concrete Road Bridge 90 years 30-100 years Crane 10 years 5-10 years Culvert 65 years 50-80 years Dam 60 years Fence 10 years Flagpole 40 years 20-60 years Floor Coverings 20 years 5-40 years Front End Loader 7 years 5-10 years Grader 10 years 5-10 years Gravel Footpath 12 years 5-50 years Gravel Resheet 12 years 5-20 years Guardrails 20 years Headwall 80 years 70-100 years Kerb & Channel 60 years 20-120 years Lifts & Transport Services 25 years Litter Bin 20 years 20-30 years Mower 7 years 5-10 years Park Bench 25 years 15-50 years Passenger Vehicle 6 years 2-10 years Playground Equipment 15 years Pumping Station 50 years Reinforced Concrete Stormwater Pipe 100 years 80-120 years Retaining Wall 25 years Road Formation 1000 years 150-∞ years Road Pavement 80 years 20-120 years Roller 6 years 5-7 years Roof 50 years 15-90 years Runway 30 years Service Reservoir 50 years Sewer Maintenance Hole 80 years Sewer Pipe 75 years 65-80 years Skate Park 50 years 50-80 years Shade Sail 15 years 15 years Solar Panel 30 years 25-40 years Splitter Island 50 years 50-70 years Sprayed Seal 15 years 12-30 years Steel Footbridge 60 years 25-100 years Stormwater Pipe 60 years 60-120 years Stormwater Pit 90 years 70-150 years Street Lighting 30 years 20-50 years Tennis Court 12 years 7-30 years Timber Decking 30 years 15-60 years Timber Footbridge 40 years 25-100 years Tractor 8 years 5-10 years Traffic Sign 15 years 10-30 years Traffic Signals 25 years 15-40 years Treatment Plant 50 years Truck 7 years 5-10 years Two Coat Seal 15 years 10-50 years Valve 10 years Water Meter 10 years

Related Pages

• Asset Management Training Manual
• Building Useful Lives
• Council Asset Useful Life Tables
• Economic Life
• Infrastructure Asset Useful Lives Report
• Lifecycle Cost Analysis
• Moorabool Shire Council Asset Service Life Spreadsheet
• Remaining Useful Life
• Residual Value
• Water Main Useful Lives

Contributors

The following site members have contributed to this page:

• Wayne Eddy
• DDanielsson
• Niranjan21

External Links & References

1. Infrastructure Asset Useful Lives - 2009 (LGA.SA)
2. Infrastructure Asset Useful Lives - 2014 (LGA.SA)
3. Boroondara City Council Asset Management Plan for Roads
4. South Dakota Municipal Asset Useful Life Table
5. Road Safety Engineering Risk Assessment Part 4: Treatment Life for Road Safety Measures (Austroads)
6. Lifecycle Cost Guidelines for Sport and Recreation Facilities (Western Australian Department of Sport Recreation)
7. Tweed Shire Council Drainage Assets Management Plan
8. Asset Lives - Felix Schrodinger's Blog
9. Levels of Service & Asset Lives - Felix Schrodinger's Blog
10. The Gold Book (SA Department of Education and Child Development)
11. Standard Life Comparison Roads and Stormwater
12. Google Search
13. CPA Australia valuation and depreciation guide
14. Fanny Mae Estimated Useful Life Tables
15. IPWEA Practice Note 12 - Useful Life of Infrastructure