Concrete Sectional Lean-to Garage

TDS_2

So, I'm looking for peoples thoughts and comments on the following plan:

We have a 1930s semi with a fairly new brezeblock garage taking up valuable space in the smallish garden. There is a driveway down the side of the house which is too narrow for any modern car (7 foot between our wall and boundary fence with neigbour).

Our thoughts are to remove the existing garage. Tis a shame since it's well built, but would make the garden much larger (perhaps 40% bigger) We would then build a replacement on the driveway. A lean-to would maximise to internal space. The driveway is a bit of a waste of space, and a garage with a wide door at the rear would maintain access to the garden w/o going through the house.

My current thought is that I will build the rear and side wall of the garage using concrete sectional panels. I see that 2 foot lengths are available on auction websites for £25. 4 foot personnel doors can be had for a few hundred, and a 6 foot garage door on the front. So far so good?

The roof will probably be pitched with the eave running adjacent to the boundary fence with the ridge 'flashed in' to the side wall of the house. No sure what to construct to support the roof.

Any thoughts / problems very welcome!

ormus

why not build it properly using brick or breezeblocks?
a proper pitch roof with either tiles or slates, and then you can always convert it to a room at a later date.
if required.

TDS_2

The main reason for concrete rather than breeze block would be cost. I'm imagining the concrete garage will come I'm at a few grand, while a proper garage would be 16k? (2m x 8m).
The other drawback is the narrow drive (2.1m). I can place a relatively thin concrete wall close to the boundary fence, but a proper brick wall requiring 1m deep foundations would push the wall back from the boundary significantly.
Let me know if my costs are roughly correct, as I agree this would be preferable.