The more consistency between different developers' code, the lower the chance of unintended consequences. This can also make it easier to spot mistakes. The house styleguide is something agreed upon within a team that is applicable to all projects. This can range from decisions over tabs vs. spaces to whether to allow !important in rules.
CSSLint is useful for this if you take time to choose the rules that are applicable to you. For example, specifying width and padding on an element will produce a warning from CSSLint's default setting.
div {
width:100px;
padding:0 10px;
}
1: warning at line 3, col 2
Using width with padding can sometimes
make elements larger than you expect.
Perhaps for your team, using width with padding makes elements exactly the size you expected.