is the above sizing of units quite common 600mm base units either side of oven housing unit and then 500mm top units either side of hob extractor/cooker hood unit ? as this is what i need for the base units and would look daft with 400mm top units wouldnt it ?? just ready to order my kitchen thats all and want to get it correct also ive run a washer waste pipe along the back wall which at moment is directly behind where the 600mm gap is for the washer ? it is 40mm pipeclipped to wall ..will this leave enough room for the washer to be pushed all the way into the gap or should i fit the pipe elsewhere adjacent ? cheers again guys