Build a replacement plan around condition, consequence of failure, supportability and credible cost evidence. Age is an input to the decision. It is not a reliable replacement instruction on its own.
1. Connect the plan to identifiable assets
Use the stable IDs and building/system relationships in your asset register. Keep the installation-date basis, dated condition assessment, significant faults, maintenance history and outstanding actions together. Record missing information explicitly.
Choose the planning unit deliberately. Replacing an individual fan motor is different from replacing an entire air-handling unit, controls and associated ductwork. State the boundary so the plan does not count both a parent-system project and its component replacements without adjustment.
2. Distinguish age, condition and remaining life
Calendar age can flag assets for investigation. Condition reflects an assessment at a particular time. Remaining service life is a forecast that depends on duty, environment, maintenance, repairability and future requirements.
CIBSE’s economic life expectancy tables provide an industry reference for lifecycle planning. They cannot establish the safe remaining life of a particular installation on their own. Do not reproduce a generic age as a site-specific inspection conclusion.
Use a range where uncertainty is material: for example, “investigate replacement within the next two to four years, subject to condition review”. That is an illustrative planning statement, not a recommended life for any equipment type. Name the assessor, date, evidence and next review trigger.
3. Prioritise consequences and dependencies
Consider safety, service interruption, guest or occupier impact, environmental consequences, available redundancy and the time needed to recover. Verify that standby equipment is usable before treating it as resilience. Record unsupported controls, unavailable spares and specialist lead times alongside physical condition.
Separate an urgent defect from a budget preference. A safety concern needs the site’s competent assessment and escalation route; placing a replacement in a future capital plan does not make continued operation safe. Likewise, a low budget ranking is not authority to defer a statutory requirement.
4. Compare practical options
Set out the viable choices: maintain and monitor, targeted repair, refurbishment, staged replacement or full replacement. Define the intended service and constraints before comparing price. A cheaper replacement may need electrical upgrades, different controls, structural work or temporary plant.
For a life-cycle comparison, use a consistent study period and include relevant operating, maintenance, renewal and end-of-period costs. RICS describes this wider approach in Life cycle costing. Record the finance team’s agreed inflation, discounting and tax treatment rather than mixing assumptions between options.
5. Build an installed replacement estimate
Label the source, price date, geography, scope, exclusions, validity and confidence of every estimate. Distinguish supplier quotations from internal allowances. Record VAT treatment explicitly; do not assume whether VAT is recoverable.
| Cost element | Illustrative allowance |
|---|---|
| Equipment supply | £12,000.00 |
| Removal and installation | £4,000.00 |
| Access and lifting | £1,500.00 |
| Controls and commissioning | £2,500.00 |
| Temporary service arrangements | £1,000.00 |
| Survey and design allowance | £1,000.00 |
| Subtotal | £22,000.00 |
| Explicit risk allowance for this example | £3,000.00 |
| Illustrative total, excluding VAT | £25,000.00 |
In a real estimate, also assess disposal, enabling works, professional fees, permits or approvals, testing, reinstatement and operational disruption as applicable. Check that allowances do not overlap. State whether inflation to the proposed delivery date is included. Never fill an unknown price with zero simply to make a total calculate.
6. Convert estimates into a phased programme
Keep the engineering need date, proposed delivery window and funding approval separate. Work backwards from the operational constraint through surveys, design, approvals, procurement, manufacture, installation and commissioning. A hotel may need to protect occupied periods or coordinate several dependent shutdowns.
Show near-term priorities in detail and later years as ranges where evidence is weaker. Present totals by building, system and year, but retain the assumptions underneath. Test sensitivities such as an earlier failure, a longer lead time or a different replacement scope. Avoid presenting a precise annual total as certainty when its major inputs are provisional.
7. Retain decisions and refresh the evidence
At each agreed review, compare actual failures, repair spend and new condition evidence with the plan. Link findings from the maintenance programme. Record why a recommendation moved, who approved a deferral, what interim controls were agreed and when it will be reviewed again.
After replacement, preserve the predecessor’s history, retire its active maintenance tasks through the agreed process and connect the new asset to commissioning and handover records. Update the programme so the completed project is not carried forward as another unfunded replacement.
This guide supports engineering and budget planning. It is not a valuation, assurance of continued safe operation or a substitute for competent inspection and design. Safety-critical decisions and applicable statutory duties need their own evidence and professional review, regardless of the forecast replacement year.