Brownfield and Greenfield projects have their own challenges.
In capital expense terms, the brownfield option is generally the cheaper option, but the site usually relies on compromises. Compromises generally relate to size and scope of works, existing council restrictions (noise, easements) and Services (Electrical, water & Gas). If the compromises are acceptable, in terms of timing - a brownfield site is much faster to develop as generally Council requirements (if reqd) are lower and faster if changing or expanding on existing use.
With greenfield sites, the outside factory layout is generally less of a compromise, so will be well laid out.
Feel free to get in touch to discuss further your thoughts or options for future food factories.
K Prelovsky, RMR Process.