my thoughts

4x4" treated posts at 4ft ish centres going as high as the walls of the building at around 12ft for 2 storey with posts concreted in 2ft

ground  floor about 1 ft off the ground to allow storage for the trampolene ect underneath in the winter months

floors constructed from 4x2" between the posts with somthing like decking boards as the floor

this would allow the upper and lower floors to follow different patterns

Thanks for your feedback gents.  Sorry I havent replied earlier.

I didnt get around to making it in the end, what with the dodgy weather this Summer.  Maybe next year.

Ive got another project in the pipeline.  On a smaller scale lol!

My nipper is into his Bob the Builder stuff and its his 2nd birthday in October.  I want to make him a kind of garage/yard for his toy vehicles (diggers and steam rollers etc).  I am thinking something with individual doors or arches for each vehicle to "park" in with each ones name above the door etc in their respective colour.  
Kind of a learning toy where he can learn the names and read and match the colours by putting the right toy into their own garage/shelter.    

I had thought of a upstairs to it also just for somewhere to store the rest of the figures if nothing else.  
Done a bit of reading on the net and would mdf be the best to use?  I plan on using pva to stick a brick effect paper on the outside walls and a tile one on the roof.  Sorry, I know this isnt a hobby forum but would a peaked roof be hard to make?  Whats the best method to fix the corner joins of the building?  A strip of batten or something and then some fine screws?
Its going to be give or take about 80cm long to accomodate each truck/vehicle side by side with room in between, and around 40cm deep.  Dunno bout height.  Any tips on keeping each individual piece square when cutting etc.  Ive made dog kennels and bird houses in the past and they've been a bit wonky!

My missus has mentioned that if he ever wanted a dolls house she would have no problem in letting him have one.  I thought this idea might be a bit more of a "mens" version and prevent him asking for a pink handbag when he gets to 16 .

As I said in my original post im not superb with wood as its not my area of expertise.  So id appreciate some advise.  Id like it to be all joint together correctly as he might still be playing with it in 4 years time.

Cheers lads.

Sorry mate, no its an inside toy.  Something he can take out the garden with him, but on nice days.

No Neils not moving in  :-D

The toys are roughly 10" x 5" x 5"