Abstract: A system which facilitates HVAC design for buildings or portions thereof is disclosed. The system comprises a server and one or more remotely situated terminals. The server, which can be a secure server, comprises software that facilitates calculation of HVAC design. A user can access one or more calculation modules in a session of use of a project. The user can provide alphanumeric information items in one or more data input fields. A calculation module can determine a variety of HVAC design output information items using the data added by the user. Both input and output information items can be securely recorded by the server in a record of a session for a project. Furthermore, multiple users can collaborate by accessing the system and contributing to the record of a project in separate sessions. A record of a session or project can be provided in a printable text file.