"added to which" is a grammatically correct phrase and can be used in written English.
It is typically used to introduce an additional point or piece of information that supports or emphasizes the previous statement. Here is an example: "The company has seen a significant increase in profits this quarter, added to which, their stock prices have also risen by 10%."
It is what makes it unusual, added to which some of the exhibits are little known.
It's a long day, added to which my dressing room is several flights up.
"Christopher Wren would turn in his grave," one added, to which councillor David Boothroyd responded: "This isn't participative theatre".
At primary school, though, he excelled only at football – he played once for Crystal Palace juniors – added to which, in his own words, he was "bone idle".
Many still share Emerson's view that "money often costs too much," added to which are recent developments indicating that it buys less and less status.
It said two years of huge losses were straining its finances, added to which Sharp was highly dependent on short-term debt.
I just got dehydrated". Temperatures in Washington in the last few days have reached over 32C (90F), added to which Petraeus said he had not had breakfast that morning.
To the reaction flask, varying number of cells was added, to which gold (III) chloride was added to the flasks and kept for incubation at 37 °C, 200 rpm for 72 h.
Demonstrating these, effects in animals require many lives to be sacrifice at intervals, added to which is a long and a lacklustre process needed before the result is acquired in most cases [38].
Later, a wide exonarthex (outer narthex) was added to which leads an elaborate door frame, featuring the Lion of Saint Mark between two Kallergis (local officials) coats of arms on the architrave.
Also we have to recognise that the study was underpowered at outset for these secondary outcome measures, added to which the proportions responding to the patient-directed enquiries were about 30%%.
