Make a garage side door wider

[s p a c e m a n]

I want to make the side door into my garage wider so it's easier to get bikes into it. The garage has got a solid concrete base and a tiled roof on some lightweight concrete blocks.

The door is 68cm from the corner of the building, so Google says that I can only make it larger in the other direction because of building regulations?

The opening is currently 76cm, I plan to make it 100cm. There's enough cable that I should be able to move that fuse board and switch over.

Just planing on making a door out of ply and a load of 2x4 timber. Probably cut the blocks with a disk on a grinder from both sides and chisel anything left over.

Anyone see any glaringly obvious problems that an idiot with a hammer doesn't know about?

[miniman]

Is there any kind of lintel above the existing door?

[s p a c e m a n]

The current door frame isn't taking any weight. There's timber running along the top of the brick the entire length of the wall that the roof is sitting on.

[s p a c e m a n]

That's just a bit of trim that they've nailed on to the timber behind to hide a gap between the top of the door frame and the timber that sitting on top of the blocks