An audit released Monday by Comptroller Tom DiNapoli’s office found errors in a half dozen MTA New York City Transit capital projects have led to delays and increased costs.

The audit, which reviewed six projects with a combined budget of $815.7 million, found design-related issues during construction in four of them, which led to delays and additional spending.

In one case, a project to install elevators and make a platform comply with the Americans with Disabilities Act, had a design that did not raise the platform edge for passengers who use wheelchairs. The mistake led to an additional $617,000 for the project’s total cost.

The MTA has a total capital projects budget of $33.27 billion, with New York City Transit’s share at $16.74 billion.

“This audit found numerous problems in the MTA’s capital projects pipeline that led to delays and cost overruns,” DiNapoli said. “These are red flags that fall within the MTA’s power to fix. As the MTA strives to improve the system for riders and overhaul its operations, we hope it takes a close look at what we found in this report and our recommendations.”

The audit was released as problems continue to the plague the troubled New York City subway system, leading to delays for riders and increased fare costs.

Some projects were understaffed and contractors’ scheduled workers were not necessarily present.

Auditors recommended the MTA determine the root cause of design errors or omissions and create action plans to keep them from re-occurring. The report also recommended quality assessments are performed and documented. Construction managers should also document specific “lessons learned” notes on additional work orders.