Thank you all for your timely responses. I too have always enjoyed the convenience of my two ovens which can be used independently of each other, which is why I am seriously considering the 1.5 double oven option. I have also researched the idea of two compact ovens which include microwave and steam options, (Bosch, Miele, Smeg AEG etc) and was all excited about that idea, but to install two of these is far too expensive. ($5000+ minimum) The freestanding convection microwave options all stipulate minimum 10-20cm airflow at the top of the unit, and the ones that do come with trim kits still all end up being too large for the space...frustratingly, often by only 2 or 3 cm! And yes, I've also lusted after an induction cooktop, but the expense of chasing wiring down a solid brick wall and disrupting backsplash tiling has put the kybosh on that idea. Anyhow, I have slept on this (again!) and have come to the conclusion that a 1.5 oven without an integrated microwave is the only way available at a reasonable cost.... A small microwave inside a cupboard might just work.... It's both interesting and noteworthy that convection/microwave +/- steam, with regular multifunction oven combinations although expensive, are readily available in several brands in the US......I'm jealous!

My suggestion would be to install two 60cm ovens. You can have meals cooking in one, and just warming in the other. Or both cooking at different temperature. Or desert in one, meat in the other. If you get a larger oven, then even if cooking one dish, you are having to heat up the whole large oven. I have two 60cm AEG ovens, they are self cleaning and are very easy to use.

I think only having 45cm ovens is too restrictive. What about 1 x 60cm oven and 1 x 45cm oven if you have room? Stacked. That is much more flexible than a single 60cm oven or 2x 45cm ovens. You can cook a main meal such as a roast with 2 or 3 trays in one and dessert in the other at the same time. Or use the smaller oven for just a cake or one tray meal and save on electricity. Or if catering for a crowd you’ve got lots of oven space. I’d definitely go with pyrolytic oven. I’m a big fan. And stacked rather than under bench. Much more ergonomic/better for your back.

the installation instructions for most ovens is usually available on the manufacturers' website and/or contact the manufacturers' customers liaison adviser directly for specific advice to suit your ovens.....too much potential problems to guess and different models may have different requirements so you need to be specific