〜に加えて
In addition to 〜に加えて
Meaning
"In addition to ~", "on top of ~".
Formation
[noun] + に加えて （〜に加え in writing）
Notes
Plainly stacks a second factor on the first, with none of the surprise that ばかりか carries. Common in reports and forecasts, where the two factors together produce one result.
Examples
雨（あめ）に加（くわ）えて風（かぜ）も強（つよ）く、外（そと）に出（で）られません。
On top of the rain the wind is strong, so I cannot go out.
Breakdown
授業料（じゅぎょうりょう）に加（くわ）えて、教材費（きょうざいひ）が必要（ひつよう）です。
In addition to tuition, there is a materials fee.
Breakdown
経験（けいけん）に加（くわ）えて、語学力（ごがくりょく）も求（もと）められます。
Language ability is required as well as experience.
Breakdown
暑（あつ）さに加（くわ）えて湿気（しっけ）がひどいです。
On top of the heat, the humidity is dreadful.
Breakdown
本業（ほんぎょう）に加（くわ）えて、週末（しゅうまつ）は店（みせ）を手伝（てつだ）っています。
On top of my main job, I help at the shop at weekends.
Breakdown
⚠️ Often confused with
〜ばかりか / 〜ばかりでなく
Not only 〜ばかりか / 〜ばかりでなく
"Not only ~, but also …".
〜のみならず
Not merely 〜のみならず
"Not merely ~, but also …" — the formal written "not only".
〜はもちろん / 〜はもとより
To say nothing of 〜はもちろん / 〜はもとより
"~ goes without saying, and also …".
〜はおろか
Let alone 〜はおろか
"Let alone ~", "not only not ~ but not even ..." — the easier case fails too.
〜すら
Not even (emphatic) 〜すら
"Even ~", "not even ~" — a written, emphatic さえ.
〜にとどまらず
Not confined to 〜にとどまらず
"Not confined to ~", "not stopping at ~ but spreading further".