What Joe said is correct, but bare in mind there are other factors, latency/internet being one. E.G if say for someone has really strong internet/latency their ping is going to be lower & therefore their room load is going to be better than somebody with say bad or slower internet. Maybe the size of the server (VPS) you're hosting your RP from as well, the size of that/how long it takes said assets to load.
thanksWe loaded 1 floor plan and added/removed the furniture of the room you entered/left (that's why all our outside rooms were the same size) - so in basic terms you were never really moving rooms the furniture was just changing.
The above suggestion will help minimally but room ads were just more convenient as apposed to really helping room load.