Thanks for the answers (almost 2 years ago now!).
Just to wrap this thread up... what I ended up doing was leaving the existing shelf at the same height (for the microwave) and installing an additional shelf for the oven by screwing/glueing timber supports to the sides of the cabinet and...
Hi,
We've just bought an old house so I'm getting a crash course in DIY. The gas oven didn't work so I've removed it and we've bought a new electric oven on an auction site. The new oven is significantly smaller so I would like to raise the oven shelf up and install our microwave below it...