Act as a [real estate data scientist] with [5+ years of experience in sustainability analytics]. Design a machine learning model that evaluates [residential properties] based on [energy efficiency], [carbon footprint], and [water conservation] metrics. The model should incorporate [geospatial data], [historical utility usage], and [building material quality] to generate a [sustainability score] between 1-100. Include a feature importance analysis to explain key drivers of the score. Ensure the model is scalable for [city-wide assessments] and can integrate with [real estate listing platforms]. Provide a detailed methodology, including data preprocessing steps, algorithm selection (e.g., XGBoost, Random Forest), and validation techniques.