Make a list of all the rooms and spaces you want in your new facility: lobby, circulation desk, picture book collection, director's office, etc. Don't limit yourself to the types of space you currently have; add new spaces, both "needed" and "wanted" ones -- see the list at right for suggestions. Trim existing rooms that are unnecessary or superfluous. Don't worry about square footage or relative importance yet.
Once you have your list, you can use standard square footage numbers (such as those in the ALA's Building Blocks for Planning Functional Library Space, 3rd ed., Scarecrow Press) to estimate the ideal size for each area. For collections, make sure you are taking into account current trends, such as smaller Reference and Nonfiction areas and expanded nonprint collections.
Describe requirements for relationships (see also Adjacencies), occupancy, general design, seating & other furniture, equipment, lighting and acoustics.
A sheet something like this one should be filled out for each area:
One of the requirements for the MPLCP grant program is the inclusion of a "summary of facility space requirements in the form of a table." The link below leads to an Excel spreadsheet with a suggested format, including formulas for total square footage and reader seats. The chart uses the complete list of spaces shown at right; feel free to edit it to fit your needs.
Meeting Room Kitchenette
Meeting Room Storage
Quiet Study Room(s)
Group Study Room(s)
Staff Break Room