The Tamar bridge is the most invisible cost line on Saltash projects. Trades crossing twice a day add small amounts of time per visit, and visits add up. Material deliveries from Plymouth suppliers are usually fine; deliveries from further west occasionally aren’t. Programme assumptions need to be honest about both.

For the Saltash refurbishment I was take-off-ing this week we mapped the trade base each contractor relied on and let that shape the rates we used. The contractor most likely to win the work has a Saltash-based core team and crosses the bridge only for specialist trades. Their number reflects it.

It’s not a romantic detail. It’s the difference between a quote that holds and one that drifts.