A slum environment is an area that commonly has characteristics of unhealthy house conditions and tends to create a crowded condition among residents. This study is intended to measure the happiness level of the household. This study also suggests an instrument that can be used to understand the happiness level. The dimensions and indicators of happiness factors were derived from Statistics Indonesia, including the dimensions of life satisfaction, feelings, and the meanings of life. The research was conducted in several slum areas in Indonesia, such as in Kali Baru Village, Cilincing District, North Jakarta Municipality, DKI Jakarta Province. The sample comprised 100 households selected using multistage random sampling. The assessment of household happiness applied the expected value rules based on the composite index. The major finding of this study is that 100% of unhappy household were unemployed.