Cleaning the facade of Parliament, much of which was covered in red paint by protesters last month, will cost around 15,000 euros.
That's according to the latest estimate, as provided by the facility's estate manager, Sari Turunen, to news agency STT.
Cleaning efforts resumed on Monday morning, with workers using steam pressure washers to remove the water-based dye which protesters splattered on the historic building last month. The work is expected to conclude on Wednesday.
Members of climate groups Elokapina from Finland and Sweden's Restore Wetlands carried out the highly visible protest on 25 September, aiming to draw attention to peat mines in Sweden run by Finnish majority state-owned energy firm Neova.
Despite previous efforts to clean the building, traces of the red dye were still visible on the structure's granite pillars, particularly in their porous seams.
The current estimate of 15,000 euros includes all costs involved in the cleaning efforts, according to Turunen, including a trial last week to see if pressurised steam would work.
She noted that the costs could still rise if there are further developments in the effort.
The cleaning efforts are being carried out following recommendations from the Finnish Heritage Agency.
Workers have used a highly alkaline, biodegradable detergent to remove the dye from seams in the granite building's structure, where the colour was particularly absorbed, according to Juha-Pekka Ryynänen, Parliament's construction supervisor.