Different types of microwaves
Today, the classic or so called mono-function microwave has been supplanted by much more elaborate versions like those with a grill for browning or melting. The latter is great for making tarts, pizza, and quiches with crusty pastry in record time! As for combined microwaves, they have both the advantages of a mono function microwave and an electric convection oven. That way, you don't really need a conventional oven as this two-in-one option is perfect for saving space.
The main criteria you should take into account
The answer to these types of questions comes from the set-up of the kitchen it will go in as well as the style of your furniture.
As for size and volume, it will depend on the family it is for. For a family of four, we would recommend a space to hold a 22 litres microwave. The diameter of the plate should also correspond to the dishes you normally use.
Lastly, in order to be efficient, a microwave should have a minimun power of 800 watts.
Evermore elaborated option
Aside from saving space, the technology in combined microwaves offers very practical day to day uses: cooking programmes, heat retention, steaming or linked cooking stages, which mean you can start in defrost and then proceed to cooking the same dish.