Lease Definitions & Terms


Base lease

A contract stating the minimum established requirements that are applicable to all tenants.

Base year

The year of a lease term that is used as the standard when implementing an escalator clause. Operating costs are judged higher or lower during the next year when compared to the base year.


An unfinished area or space between a row of columns and the bearing wall. Usually the smallest area into which a building floor can be partitioned.


A competitive system in which each bidder submits a sealed proposal to execute construction work for a specified sum. The list of bidders (bid list) is controlled by the client and architect.


A preliminary agreement evidencing a meeting of the minds and effective until the principal agreement can be executed.

Building core

The central or arterial part of a multistory building that integrates functions and service needs for established occupants. Such areas are normally composed of toilet facilities, elevator banks, janitors' closets, utilities, mechanical facilities, smoke shafts and stairwells.

Building permit

The approval that must be obtained under state or local regulations. Drawings an specifications must be filed with the legal authorities in control of building operations.

Building shell

The skeleton of a building to which the finished exterior and interior are applied. It includes the building foundation.

Building standard

The specific construction standards that have been established by the owner and architect to achieve a uniform element of design throughout the building and to establish a cost basis for fitting up charges and/or allowances. Such items may be changed only with the approval of the building owner or the managing representative.

Build Out

The construction or improvements of the interior of a space, including flooring,walls, finished plumbing, electrical work, etc.


An agreement between a landlord and a new tenant whereby the landlord assumes the obligation of fitting up the demised space to the tenant's specification within the constraints of building standards. The tenant takes possession when the space is completed.