The three-storey building collapsed late Tuesday possibly due to digging for an adjacent house under construction, IANS news agency reported citing fire brigade officials.
At least 22 people were injured, city police Sub-Inspector Mohammad Akhlak said. The area was cordoned off and a search for survivors started, Akhlak said.
Many buildings in older areas of the capital do not adhere to safety regulations.
"This was a disaster waiting to happen. The Municipal Corporation of Delhi never bothered to check the structural safety of old buildings," Delhi's Food and Civil Supplies Minister Harun Yusuf said.
A five-storey building collapsed in the capital in November 2010, killing at least 60 people.