Light coloured cladding options

[Crofter]

In order to create two different colours on the walls, we're going to use larch plus another lighter coloured material. In the attached sketch, I'm talking about the light brown section of the wall (I was just using the closest approximation I could find in SketchUp)

At the moment I'm penciling in corrugated steel, because I've worked with it before and it's easy, cheap, and durable. 

I am a tiny bit concerned that a white or cream colour (which is what we want, and will likely be required by planning anyway) will show up every last speck of rust. Not that we expect that to be a significant problem as the plastic coated galv stuff has something like a 20yr guarantee. 

SWMBO isn't sold on the idea, she is fine using it for the roof but not convinced about using it on walls.

 

What other options are out there? Essentially we want it to look like white painted rendered blockwork from a distance. So smooth and white is the goal. 

I don't really want to use blockwork as I'll be doing all the labour myself and I'm a pretty slow brickie. It just seems like a lot of work and cost for what is in effect a rain screen. 

 

@ProDaveused some form of rigid insulation board as his cladding, that sounds interesting. 

Another option might include fibre cement.

 

Budget is pretty limited... last time I checked, corrugated steel was about £10/m² so I'm going to need some persuasion to spend too much on this...