Can you buy ready made house plans to work from or would you have to hire an architect?

Just wondering as im considering a small self build project but the budget is tight and i wondered if you could buy ready made plans to save the expense of getting an architect to design a house for you. Iv looked at severall of the timber frame house companies who have a catologue of their standard designs but i wondered if there were any companys who produce standard house designs for self build using traditional block/brickwork. Have googled it with no success so any help is much appreciated.