Rating System

LEED O+M: Existing Buildings

Rating System Version

v3 - LEED 2008

Inquiry

111 Sutter St. is a nationally registered historical building built in 1927 in downtown San Francisco. When the building was originally designed and built it used a combination of operable windows and two fresh air shafts to cool and ventilate the building. These design elements were used because air conditioning had not been introduced yet. Over the past 80 years tenant improvements have been made with some choosing to install supply air fans off of the open air shafts in the building. These supply air fans are owned and operated by the tenants and the building has no control over their maintenance or operation. Spaces without supply air fans are naturally ventilated through the use of the operable windows and many of the spaces with supply fans do not use the units regularly. Due to the fact the supply fans were not purchased by the building and are not maintained by the building they are not considered to be a part of the base building system and have been excluded from the project. This classifies the building as a naturally ventilated building, requiring it to meet the standard set forward in ASHRAE 62.1. In section 5.1 of the ASHRAE standard it states "The Standard has an exception for engineered natural ventilation systems when approved by the authority having jurisdiction. Such systems may comply without meeting the prescriptive requirements described above". The state of California is the regulatory agency that monitors the project site and according to Title 24 chapter 8 in the California Building Standard the building is not required to be up to code unless a major renovation has been made. Since no major renovation has been made it has not been required for the building to take any steps to upgrade its ventilation system, but it does meet the requirements set forward by the local regulatory agency, thus meeting the standard set forward in ASHRAE 62.1. This qualifies the building to meet IEQ prerequisite 1.