Abstract The building sector has become a major source of worldwide carbon emissions and energy consumption because of rapid population growth and a continuous environmental strain caused by humanity. A lack of consistent data on life-cycle carbon emissions and energy demand at the neighbourhood level has made it difficult to understand the origins of climate change at this scale. A sensitivity analysis brought clarity concerning the extent of environmental impacts on future climate evolution. From this perspective, the authors aimed to evaluate, analyse, compare, and provides recommendations to reduce carbon emissions, as well as the energy required by three types of neighbourhoods (urban, rural, and sustainable) located in and adapted to all countries worldwide. The most important parameters affecting carbon emission and energy consumption were analysed, including the energy mix of countries, local building materials and climate, technological solutions utilised, daily mobility, and occupied spaces. The results indicated that the highest levels of carbon dioxide emissions were produced by countries with prosperous economies, such as China, the United States, India, Germany, and Poland, because of high concentrations of coal in their energy mixes. Modernising cities through the construction of new eco-districts and increasing the use of new techniques for substantial renovations of outdated buildings worldwide could mitigate the amount of greenhouse gases emitted by neighbourhoods 53–97 % by 2050. Moreover, by combining substantial building renovations with the installation of photovoltaic panels on roofs, the objective of ‘zero carbon’ at the neighbourhood level could be achievable by 2050 in rural neighbourhoods. Radical changes in the judicious choice of construction materials and use of green energy production represent targeted opportunities to resolve the future climate dilemma.