kryptonjohn: You don't "have" to remedy it - it's OK to sell with the non permitted structure noted on the LIM, just as it is legal to sell a house that doesn't have a C&C for work done. The risk is that it pushes down your sale price.
But in the case that it's a 3x3 garden shed sitting on the ground... if I was a buyer I wouldn't personally care if it was noted on the LIM as an unpermitted structure due to its temporary nature and the fact that I could simply remove it if I ever felt the need.
The real risk is getting a grumpy neighbour complaining to the council as happened in the news story cited earlier in this thread.
Correct. The thing is the council has no record of unconsented work so the LIM report misses it. The only way a purchaser can identify it is to compare what's on the ground with what's in the council building file. That's quite a tall order for many purchasers and requires some knowledge of the building code. So it comes down the vendor's warranty in the S&P Agreement.
I'd say most purchasers, if they find out there is unconsented work, want it remedied. Which is the last thing you need in a sale process.
I guess what I'm saying that if you're building something that needs a building consent then you should get one.