There's little supply to match demand for flats worth less than Rs 30 lakhs in major cities. But as demand slows down, things are changing, with developers like Puruvankara foraying in middle income housing using their own land and buying more. "This is a different segment entirely. It caters to people who want flats for under Rs 20 lakhs. There is a huge gap in that segment. Margins will be at 17-18 per cent for the project," said Ravi Ramu, Director, Puruvankara Projects.