Not every DIY conservatory that we do is straight forward. There are sometimes things that get in the way of the conservatory site such as drain pipes or soil pipes. Normally with a little skill these can be moved or relocated so that they will not foul the conservatory.
However, there are other ossacles that can be more of a challenge. These would include central heating boiler flues which although placed at a reasonable height, would cost the earth to have moved. Another favourite is the good old extractor fan outlet. Again hard to move.
If the DIY conservatory is a Lean - to, we can usually get around this by reducing the roof pitch and altering the frame heights as well. This has worked very well in the past with low pitch lean - to styles. Obviously there are styles which will not work such as a Victorian or Edwardian self build conservatory, due to the much higher ridge height.
Before you even think of ordering a self build conservatory, these are the things, along with man holes and drains, that need careful consideration. Failing to allow for these obstacles can be a recipe for disaster, which is something that we avoid like the plague!