A general concept for designing self-assembling peptide fibrillar nano- to microstructures is described. The approach relies on the use of straightforward alpha-helical one-heptad (approximately 1 nm) modules without the need for more-specific designs. Various combinations of the modules gave a variety of constructs that were examined by a combination of spectroscopy and microscopy. These show that simple rearrangements and stereochemical conversions of the modules within similar templates lead to different fiber morphologies. The concept opens new strategies for designing fibrous materials with tunable properties at the nanoscale.