Will my boiler be sufficient with additional radiators added?

We are adding a room to our 1560 sf home which will make the total size of the house 2,000 s.f. We want to heat the room with radiators as is the rest of the house. Our current boiler is 150,000 input, 120,000 output. Will we need a larger boiler to add a radiator or two to the new 400sf space?