The article is devoted to the use of modifying additives into the concrete mix during the construction of multistorey buildings. Additives accelerating concrete hardening allow it to quickly build upper floors, but increase the cost of concrete mixes. Thus, reduction of the holding time will not be cost-effective if concreting is not a leading process in scheduling. To determine the effectiveness of additives, the schedule of construction of a multi-storey building with a reinforced concrete frame was optimized. The main optimization methods are changes in the construction technology taking into account the use of various types of additives (superplasticizers, waterproofing additives; season; the method of lifting concrete mix to the floor). Relamix-M2 and Penetron-Admix" reduce the concreting time by 37%; the cost of one m 3 of concrete decreases by 2.5%.