Plinth or Floor
You must make sure that your floor is strong enough to carry the weight of the Aga:
2 Oven = 1/2 Ton
4 Oven = 2/3 to 3/4 Ton
The plinth must be at least 25mm of non combustible material.
A plinth is not essential, there is no reason why an Aga shouldn't sit on the floor. But if you want to have the Aga sat at the same height as a worksurface then take:
850mm from the worksurface height for the plinth height for a Traditional Aga
840mm from the worksurface height for the plinth height for a Deluxe Aga.
The plinth dimensions should be the same as the base of the Aga:
2 Oven = 987mm wide
4 Oven = 1487mm wide
The dimension of a Deluxe plinth is 679mm from the back wall. This can be slightly reduced to 665mm if the front of the plinth is going to be tiled.
The dimension of a Traditional plinth is 665mm from the back wall. This can be slightly reduced to 640mm if the front of the plinth is going to be tiled.
No matter which type of plinth is chosen, it must be smooth and level.