Quantifying Savings & Avoiding Pitfalls10 / 13
Common Pitfalls & Overstatement
Boundary changes, occupancy underestimation, weather luck, rebound effects; how to avoid.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
M&V is as much about integrity as arithmetic. Savings can be overstated - deliberately or accidentally - in many ways. Knowing the common pitfalls is essential to producing numbers that withstand scrutiny.
In this lesson
- 01Boundary changes
- 02Ignoring or under-counting drivers
- 03Weather luck
- 04The rebound effect
- 05Selective data and cherry-picking
- 06Over-fitting the baseline model
- 07Optimism in predictions versus measurement
- 08Persistence and drift
- 09The overstatement trap
- 10Sources and further reading