Bike Shed *incorrect link* A similar lean-to, one completely enclosed to match the home exterior, would be perfect on the garage wall. If it were accessed from inside the garage only, it would be harder to steal + less likely to rust.
inspiration: Beautifully designed and painted 'Oxford Lean To Shed' sold by English company Next. Shed with lean to extension for log storage shown painted in Heritage green garden paint. via gardenista