Building sector in Sweden constitutes a major part of the overall energy consumption, making up for around 40% of the total energy use. During the 60s and 70s, there was a big surge in housing in Sweden with over a million dwellings, both single family houses and multi-family apartments, constructed over a period of ten years. These buildings constructed according to the pre-oil crisis standards, suffer from poor energy performance and are in dire need for large scale renovations. This makes it a very interesting area to focus on to meet the Swedish government targets of 50% energy reduction by 2050. This study tries to assess the prevailing situation in multifamily housing sector and focuses on various obstacles and hinders in the path towards achieving long term energy saving goals. A model has been developed using bottom-up approach to study different scenarios for energy use in 2050 based on various renovation possibilities in the building stock.