Kier Construction has won a £2.2m contract with Liverpool City Council to extend two special schools in Palmerston and Abbot's Lea.
The schools, both in the suburb of Woolton, will be extended to cater for increased demand for places.
Palmerston, which teaches secondary aged children with severe learning difficulties, will get four extra classrooms to provide a post-16 centre and enable it to take on a further 48 pupils.
Abbot's Lea, which specialises in supporting youngsters with autism, will get an six additional classrooms. The council said the investment in the site will save the city council £2m a year as it means it will not have to send around 40 pupils on the waiting list for places next year out of the city to be educated.
The new classrooms will have solar panels on the roof to keep energy costs low and will open in September 2013.
Kier Construction was set a target of ensuring that 65% of spend and employment is within the city, with 85% from across Merseyside.