To achieve a sustainable development, all related levels and sectors of policy making need to be in line with environmental considerations. Iskandar Malaysia, the second significant regional economic project of Malaysia, in an effort to be recognized as an international standing sustainable development, has formulated its policies in the form of 32 blueprints. Each of these documents targets a specific development aspect. Out of these blueprints, Environmental Planning Blueprint (EPB) aims at ensuring that all aspects of development are environmentally sustainable. This study tried to figure out if other blueprints are in line with principles and guidelines of EPB. Therefore, we selected Livable Neighborhood and Design Guidelines Blueprint (LNDGB) as a sample and assessed its horizontal policy coherence with EPB. Content analysis used as the main method of the assessment. Results showed that LNDGB mostly was coherent with policies of EPB and no serious contradiction found between them. However, LNDGB did not cover all features determined by EPB.