The HETEKA project aims to advance carbon neutrality and energy efficiency in district heating networks by developing and researching innovative solutions for apartment buildings of various ages. Its core objective is to promote the development of carbon-neutral and energy-efficient solutions that utilize district heating networks and to investigate innovative district heating solutions related to diversifying energy production through simulations and co-creation. These innovative solutions enable the existing district heating network to be used across a broader temperature range cost-effectively and without compromising residents' thermal comfort. The project will select three apartment building sites of different ages in the Uusimaa region. Innovative solutions for these sites will be investigated using computer modeling, with a particular focus on energy efficiency and cost-effectiveness. HETEKA continues the development work initiated in projects like HUKATON and BLOCKCC, which focused on improving the energy systems of residential properties and areas. The project's goal is to leverage the existing district heating network more extensively and cost-effectively, without decreasing residents' thermal comfort. The HETEKA project will broadly engage companies, property owners, and experts in the Uusimaa region in co-creation within reference groups, which is central to the project's approach. This ensures the results are directly implemented within the business sector. Additionally, the project will draft an action proposal for industry stakeholders for further development, guaranteeing the widespread applicability of its findings.