Traditionally Lierskogen has been a place living from farming, but after World War II many new families have moved in. These families have usually been living there, but non-agriculture work is scarce. So they have mostly been working in nearby places like Asker, Dikemark, Drammen and Oslo.
The old village centre was situated near the church, Lierskogen chapel. Around it was the following buildings: Gravdal bakery, Heia children school (for children aged 7-12), the society house, a small shop, a post-office and a petrol station. In 1985 Lierskogen had a population of only 900 people. But it was around this time a great building boom began.
During the second half of the 80's two major projects was built from scratch: The Liertoppen shopping centre and nearby Norsk Medisinal Depot, a pill factory. In 1987 Liertoppen shopping centre was opened with two separate buildings and a huge car park. An underground car park was also build under one of the buildings. In 1989 the two buildings was connected together with a bridge and then forming Norway's longest indoor shopping lane.
In the 1990's the major building project was of several dozens new houses right behind Heia children school in the old village centre. This settlement is called "Legoland" among the villagers, due to the doll's house-like design of the houses.
Even though this settlement and several smaller ones has doubled the population to 1800 people, the commercial centre of Lierskogen has moved 1.5 km away, up to the Liertoppen shopping centre. The post office etc. has left the old village centre for a place among the shops.
Due to the close distance to other growing places like Drammen, Asker and Oslo, Lierskogen has continued to grow. The house prices has increased yearly. With good communications around the future looks good for Lierskogen. (Norway's busiest motorway Oslo - Drammen goes straight through Lierskogen).