Need to tips for a house construction

Hi everyone, I recently got an LDA house in Gomti Nagar, Lucknow. It’s a 1250 sq. ft. property, and I’m planning to reconstruct it into a 3-floor house. Since I’m relatively young and don’t have much experience with construction, I was hoping to get some tips and advice from the more experienced folks here. Some specific things I’m curious about: 1. How to make the best use of the space (open layouts, future needs, etc.)? 2. Any recommendations on materials, construction techniques, or contractors? 3. Things to consider for a strong structure and compliance with LDA regulations. 4. Any must-have modern features or tips to save on long-term costs? Looking forward to your suggestions and insights! Thanks in advance!