Building a porch

Hi, I was hoping to get some advice with regards to building a porch. Have had a look through but can't seem to find the answers I need. It will be built onto two adjoining walls with the two new walls of the porch both being 2m long and approx 2.5m high. One door (obviously) and one window. As it will be fairly modest I don't want to build a cavity wall, my thoughts are 4 inch block work with 1 inch exterior render and then plastered internal walls. Does this sound ok? or should the blockwork be thicker than 4 inch.

Cheers in advance

So long as it remains a 'porch' then what you have suggested sounds reasonable. There is a condensation risk, even with a porch but just crack a window in the very cold wintertime to equalize things.

Thanks noseall for your reply much appreciated.