Current models for room acoustics simulation suffer from an accuracy v/s efficiency trade-off, with highly accurate wave-based models taking several hours at best, and real-time synthesis with delay networks lacking in accuracy. The goal of the Scalable Room Acoustics Modeling (SCReAM) project is to develop a unifying room acoustic model that balances this trade-off and offers breakthrough scalability properties. To this end, we propose to use the Scattering Delay Network (SDN) as a starting point. The SDN runs in real-time, is adaptive to moving source-listener locations and renders first-order reflections exactly while approximating higher order reflections. In this talk, I will discuss recent developments in the SCReAM project relating to higher order SDNs, new network topologies and re-designed scattering matrices. If time permits, challenges of designing stable scattering matrices based on material properties will be discussed.