An office building (sthlm new hus 4) located in the south of Hammarbyhamnen overlooking Hammarbybacken is planned in 2018. Climate control of the office building are via radiators, high-temperature chilled beam and pre-treated supply air. The building is currently being designed for district heating and remote cooling. The study aims to investigate whether borehole thermal energy system (BTES) are a reasonable alternative to provide the office building with heat and cooling, from an environmental- and life cycle cost (LCC) perspective. The aim of the study is to generate an energy requirement for the office building, which is done by construct a model of the building using IDA ICE, a simulation software. The energy requirement is covered by either district heating/-cooling (energy system I) or BTES (energy system II) as the primary energy source. A model of the BTES is constructed in excel based on data from experience input. Life cycle cost analysis are used for economical comparison between the energy systems. The environmental assessment is based on Nordic electricity mix, which controls the impact of the energy systems. Energy system II entails a need for energy support to avoid over dimension the heat pump, which is done by complementing the surplus need through district heating and remote cooling. LCC shows an economic breakpoint at 11-year calculation period, where BTES becomes economically advantageously. Environmentally, energy system II releases 14.3 tonnes of CO2eq compared to energy system II which results in a reduced emission of 47 tonnes of CO2eq based on Nordic electricity mix.