Requirements for renovating residential buildings in the Netherlands towards lower temperature supply from district heating.

In the Netherlands, district heating with a lower temperature supply (<70°C) will play a crucial part in accomplishing the energy transition goals of delivering natural gas-free sustainable heating to dwellings. The existing dwellings often require energy renovations to make them suitable for lower temperature heating. However, choosing renovation strategies that promote the transition to lower temperature district heating while improving energy efficiency and thermal comfort is challenging. This study aims to identify minimum renovation requirements for comfortably heating homes using lower temperature heat from district heating. Identifying minimum renovation strategies to prepare existing dwellings for lower temperature district heating would be vital in addressing the European Renovation Wave's target of improving worst-performing buildings. For the same, the study uses a typical intermediate terraced house built before 1945 as a case study to investigate renovation strategies based on four levels of renovation intervention (no renovation, basic, moderate and deep). The impact of renovations on space heating demand and thermal comfort was tested with medium (70/50°C) and low supply (55/35°C) temperatures against key performance indicators (KPIs) using dynamic simulation. The study found that for the case study dwelling, moderate renovation strategy of upgrading the building envelope insulation by 0.40 W/m2K for opaque parts and 1.5 W/m2K for glazing, improving the airtightness by 0.3h-1 and replacing existing radiators with LT radiators can be considered as a no-regret solution for comfortably heating homes with both medium and lower temperature supply from district heating.