Changing the Size of a Part.

local part = game.Workspace.Part1
local delta = 1
while true do 
    part.Size = part.Size + Vector3.new(delta,delta,delta)
    wait()
end

Be careful! That's an infinite loop. You'll probably want a way to break out of it before the brick gets too large.

maybe while part.Size.X <= 200 do instead of while true do

Good luck!

Just to quickly add on to what AxeOfMe posted, when resizing parts you generally need to reposition the part to it's initial position (by changing it's new CFrame to its old CFrame) once the resizing has been done.

local part = game.Workspace.Part1
local oldcf = part.CFrame

while true do
    part.Size = part.Size + Vector3.new(1, 1, 1)
    part.CFrame = oldcf --reposition the part
    wait()
end

local part = game.Worksace.Part1;
for i=1,100 do
part.Size=Vector3.new(i,i,i);
wait();
end