The IATF Rules 5th edition address this in 6.5.1c). You will need both a Stage 1 and Stage 2 audit for your new facility. Before the Stage 1 audit can be conducted, you must have 12 months data for key indicators and performance trends, among other items. The Stage 2 audit is conducted within 90 days after confirmation that Stage 1 shows sufficient readiness. If you allow 8-12 weeks to obtain a certificate after the Stage 2 audit, you should plan on your new plant becoming certified 17-18 months after start of production.
Having other certified plants will not help your cause, unless you are certified to a corporate scheme in which case the number of audit days may be adjusted.