A persistent challenge in sustainability transitions is the uneven uptake of interventions such as renewable energy projects, conservation measures and rewilding initiatives. These often encounter resistance that cannot be explained by economics, technical feasibility or governance arrangements alone. Instead, they hinge on questions of legitimacy and cultural alignment. Existing frameworks, including socio-ecological systems and cultural ecosystem services, recognise human dimensions but lack tools to identify the symbolic dynamics through which interventions are interpreted, accepted or contested. This paper advances the concept of Code Ecologies, where sustainability transitions are understood as a co-evolution of cultural, ecological and technological change. It contributes the Symbolic Ecology Framework, which integrates symbolic codes into socio-ecological analysis. Symbolic codes are defined as patterned systems of meaning expressed through aesthetics, aspirational values and common practices. They filter legitimacy and shape whether interventions are embraced, negotiated or resisted. The framework specifies six attributes – salience, valence, resonance, legitimacy, diachronic status, and place-binding – by which codes can be systematically assessed. These attributes are aggregated into a Symbolic Alignment Index, with results visualised as cultural alignment maps. An application to renewable energy siting illustrates how the framework can be applied to identify potential misalignments and support culturally resonant intervention design.