Defo go for brick if you can.

The only way to find out if you need planning or not is by calling the council I think to have a sectional garage the size of the one I am building in bricks needed either planning permission or building regs due to the size of the floor coverage. Best to look into it as I thought they didn't need planning due to not being a permanent structure.

I'm currently a little way through building mine (walls nearly up) and I am doing it on a budget. I have put aside 10k in total and its going to be close. Thats with doing all the labour myself, getting the materials cheap and also having a friend who works in plant hire so I got the plant for nowt too.

I have a thread on TS Here if interested . Its dims are 7m x 10m so will easily fit 4 cars in it. As an idea of costs the concrete (12m3) in the footings alone was £750 odd. The floor (8-9m3) was another £700. All the blocks, bricks & dust were 1k and thats on the cheap as its 1500 bricks & 1500+ blocks, plus 50 bags of dust. Christ knows what it would cost me to have a firm of builders do the whole lot start to finish, One builder quoted me 4.5k just to lay the bricks and that was with me labouring for him!!!!