Building Lifecycle Cost Calculator
The whole-life cost of a building or an option — capital plus discounted operating, maintenance and replacement costs over its life — so a cheaper build can be compared honestly with a cheaper-to-run one.
Capital cost is paid once.
How the building lifecycle cost calculator works
Capital cost is paid once. Operating and maintenance costs recur every year, and a discount rate makes a cost in year 30 worth less today than the same cost in year 1. The whole-life cost is capital plus the present value of everything that follows.
The result is that a building costing 10% more to build and 20% less to run is usually the cheaper building. The comparison only works when both options are costed over the same life at the same rate.
Formula: WLC = capital + Σ annual / (1 + d)^t + Σ replacements / (1 + d)^t
Worked examples
| Inputs | Whole-life cost | Note |
|---|---|---|
| A 4.2 million building over 50 years | 9,647,119 | capital is well under half |
| A cheaper-to-run option | 9,187,832 | compare the whole-life figures |
| A higher discount rate | 7,231,216 | the future counts for less |
FAQFrequently asked questions
What is whole-life cost?
Capital plus every cost the building incurs over its life — energy, cleaning, maintenance, replacement — discounted to today. It is the honest price of a building.
Why discount?
Because a cost in thirty years is worth less than the same cost now — you could invest the money meanwhile. The rate is a policy choice; public bodies publish theirs.
What share is capital?
Typically a third to a half over 50 years. Operating costs dominate, which is why a cheap building is rarely the cheap option.
What discount rate should I use?
Three to five per cent real for public work; higher for commercial. A high rate favours low capital cost; a low rate favours low running cost.
How do I compare two options?
Same study period, same discount rate, same cost categories. Then the lower whole-life cost wins, regardless of which was cheaper to build.
Where these figures come from
- Sabine (1922) — Collected Papers on Acoustics — the reverberation-time equation
- CIBSE Guide A — Environmental design — daylight, comfort and ventilation criteria
- Neufert — Architects' Data — the standard reference for space and dimension
- International Code Council — International Building Code — occupant load and egress factors
- Australian Building Codes Board — National Construction Code — the body that writes Australia's building code
Last checked: September 2026. Formulas are the standard building-science and code relationships; default thresholds are common international values and should be replaced with the ones in your code.