The administrative center of the municipality is Oitti, but politically there sometimes emerges debate on which centres should be developed and/or made targets of public investment.

The first estates in Hausjärvi sprung up around river Puujoki, and the inhabitants were known to practice hunting as well as slash-and-burn agriculture.

The villages of Hyvinkää and Riihimäki, in particular, benefited heavily from becoming junction stations, and they were granted independence from Hausjärvi as market towns in 1918 and 1922, respectively.

Later on, the village of Oitti, aided by its station on the Riihimäki–Lahti section, became the administrative center of the remaining parts of Hausjärvi.

It manifests as a wide ridge in the southeast, and reaches a height of 150 metres (490 ft) above sea level around lake Erkylänjärvi.

In addition, a fragmented esker reaches from Hikiä to the parish village, Lavinto, Turkhauta and Hämeenlinna, where it is known as Hattelmalanharju.