After the Little Parliament was completed in 2004, Parliament began to prepare for the renovation of its other properties. Although the point of departure of this project was the modernisation of the technical facilities of Parliament's buildings and structures, the renovation also aims to improve safety, energy-efficiency and accessibility.
The renovation progressed in phases with only one building or building part being worked on at a time. This enabled Parliament to continue working at Arkadianmäki throughout the renovation project. In an effort to minimise rental expenses, civil servants and MPs' personal assistants worked in less spacious premises in different stages of the renovation by, for example, temporarily sharing offices. Each phase of the renovation was budgeted and put to tender separately. All of Parliament's buildings, with the exception of Little Parliament, are protected under architectural heritage conservation rules.Parliament's renovation project progressed in phases:- Building A (MPs' offices and the south housing wing) 2010-2011- Building B (MPs' offices and the new public entrance) 2009-2010- Building C (library and administration building) 2012-2013- Building D (former Association of Finnish Cities building) 2014-2015- Underground facilities 2010-2014- Parliament House 2015-2017Plenary sessions were held in the Sibelius Academy building during the renovation of Parliament House in 2015–2017. The building is in the same block as Parliament House and its concert hall underwent an alteration to make it suitable for plenary session work. The entire building was leased by Parliament and the majority of the committees, among others, convened there. The final plenary session at Parliament House before the commencement of the renovation was held on 13 February 2015, after which the entire granite fortress was transformed into a building site. A fully renovated Parliament House was opened in September 2017.