Figured it out - Having was the solution.
SELECT
projects.UserId,
projects.Name,
projects.Categories,
LENGTH(projects.GeneratorUse) AS Lgen,
LENGTH(projects.FuelTypes) AS Lfue,
LENGTH(projects.FuelTypeOthers) AS Lfto,
LENGTH(projects.SpecialNeed) AS Lsn,
LENGTH(projects.FirePlan) AS Lfp
FROM
projects
HAVING
Lgen > 0 or
Lfue > 0 or
Lfto > 0 or
Lsn > 0 or
Lfp > 0