Share of building materials in the greenhouse emissions is recognized in the built environment. The share of materials and products will only increase in the future as entire greenhouse emissions in the project lifecycle, when using emissions are reduced. Responsibility for reducing material emissions falls to all industry operations, not just material suppliers. Designers and contractors can use their own choices contribute to low-carbon products and solutions ending up in permanent production. The proportion of concreate components containing steel in the emissions of residential apartment building is significant, so the research was natural to narrow down to dealing with these materials. The goal of the work was to find out greenhouse emissions of horizontal structures of a residential apartment building and note the cost and scheduling impact of various solutions. The aim of the study was to discover and explore solutions, which are possible to implement with current data. The calculations used the quantities and plans of actual object as well as the common structural solutions of the target company. The structures to be compared were the cavity slab and the site cast midsole as well as low-carbon versions of these. Greenhouse emissions of the cavity slab structure were 0,9 per cent lower than the spot cast midbase, when the product phase A1-A3 was used during the period considered. The emission reduction of the low carbon cavity slab base was given as 5,9 per cent compared to traditional cavity slab. The intermediate base of the cavity slab is according to the result of the study 15,2 % cheaper solution than spot molded intermediate slab. Costs include work, material and residual or support. If traditional cavity tiles are switched to low-cardon versions in the intermediate soles, increases the cost by 4,2 percent. The work also investigates the case of all cavity tiles are less environmental laden. A spot on the molded midbase can be used lower cardon concrete when development of compressive strength is slower than with ordinary concrete. With a 20 % reduction in concrete emissions, the development of mold discharge requires a day more compared to ordinary concrete. The lengthening of the frame schedule also causes increase in indirect costs. Site operations, staff members and working machinery as a tower crane is required for the entire frame installation. Results obtained in the study are useful for practicality. The solutions to compare are real products. Low cardon cavity slabs have also gained practical experience, which confirms the new product computationally modelled emission reductions for the new product. In addition to emissions reductions, the product is suitable due to scheduling requirements, as the solution supports the shortening trend of turnaround time of the construction site. The importance of low-carbon solutions for development in the construction sector is important. The study was limited to a narrow area in the structural parts of the residential apartment building but reducing greenhouse emissions will be a part of every planned solution and construction material used.