Project cost estimates are a key component of the regional system planning process and provide a basis for key decisions to address both regional and local transmission system upgrade needs. The purpose of this document is to provide consistent cost engineering terms and definitions and a standardized approach to cost estimating in the region.

This document also outlines the active review and reporting of cost estimates throughout the project life cycle from the planning and design to the construction phase. The proposed process covered in this document will improve the ability for transmission owners in the region to provide common estimates, increase project costs transparency and provide regular information about the transmission investments made in the region and their impact to rates.

This document complements the current regional planning process and provides additional level of detail to the project cost estimate review and validation. These guidelines have been assemble with the collaboration of the New England Transmission Owner and will serve as supporting document to the existing planning procedure.