Three.js Exterior Rendering

I need a three.js developer to build an exterior-only architectural visualization. The scene should load one or more provided OBJ/GLTF models, apply realistic PBR materials, and render with physically correct lighting and shadows. Users must be able to rotate, pan, and zoom with OrbitControls while the frame rate stays smooth on desktop and mobile. Core requirements • Three.js r155+ with ES6 modules • Environment map or HDRI for natural reflections • Directional sunlight and soft shadow mapping tuned for architecture • Responsive canvas that resizes with the browser window • Clean, well-commented code plus a short README outlining how to swap models and textures Optional but appreciated • Basic UI (dat.GUI or similar) to toggle materials and daylight angles • Lazy loading for large assets I will supply the building model, reference images, and texture assets. Please estimate delivery time, describe similar exterior projects you have completed, and mention any performance optimizations you plan to implement.