Cost Trending
Pricing changes as they emerge, not months later at the next estimate.
Quick Answer
Cost trending is the practice of logging and roughly pricing potential cost changes, such as design revisions, owner requests, or discovered conditions, as soon as they are identified. Each trend is tracked until it is accepted, rejected, or incorporated. The running trend log shows how the budget is moving between formal estimates, giving the owner early warning.
The Full Picture
Formal estimates happen at milestones, often months apart. Between them, the design keeps changing through meetings, consultant coordination, and owner requests. Cost trending exists to capture the cost of each of those changes as it happens, so the team isn't surprised when the next estimate lands.
Mechanically, the team keeps a trend log. Each entry records a description, its source, the date identified, a rough cost and schedule impact, and a status such as potential, pending decision, approved, or rejected. Entries are usually priced at a rough-order level first and refined as details become clear. The log is summed to show the net effect on the budget or the current estimate.
In practice, the preconstruction manager reviews the trend log at regular owner or design meetings. A trend might be the structural engineer increasing column sizes, the owner asking for more data rooms, or the latest drawing issue adding a canopy. Each one gets a number and a decision owner, so choices are made with cost in view rather than discovered later.
During construction, the same idea continues as tracking of potential change orders. In preconstruction, trending is how a CM keeps design on budget between estimates. Its common failure is the log that lists issues without prices, or prices without decisions, which provides visibility without control.
Real Examples
Common Misconceptions
People assume: Cost trending is the same as change order tracking.
Actually: Change orders are formal, priced contract changes. Trending captures potential changes earlier, often before anything is drawn or contracted, which is exactly when decisions are cheapest.
People assume: Trends only need a price once they are approved.
Actually: The point of trending is to put a rough number on an idea before it is approved, so the decision is made with cost in view. Waiting for approval defeats the purpose.
Does MeltPlan Solve This?
Partially — adjacentPartially — MeltPlan handles drawing revision tracking, which is closely related to cost trending. MeltPlan's Design Review compares drawing issues and flags what changed between revisions, so design changes that should become trend log entries don't slip through unnoticed. Pricing each trend and managing the trend log remain with your preconstruction team.
Catch every change between drawing revisions →Frequently Asked Questions
What is a trend log in construction?
A trend log is a running list of potential cost and schedule changes, each with a description, source, rough cost impact, status, and decision owner. It shows how the budget is moving between formal estimates.
How is cost trending different from cost forecasting?
Trending tracks individual potential changes as they emerge. Forecasting projects the total final cost of the project, and it uses the trend log as one of its inputs.
Who is responsible for cost trending?
Typically the CM or GC's preconstruction manager during design and the project manager during construction, with the owner's representative reviewing and deciding on each trend.
Why does cost trending matter in preconstruction?
It keeps design decisions tied to cost between milestone estimates. Without it, dozens of small changes accumulate unseen and appear all at once as a budget overrun at the next estimate.