Truth is, when it comes to noise flats are almost always a bad option as you can't choose your neighbours, people often move out and thus the possibility exists that new, noisy neighbours move in. Plus, with developers in the UK being extremely keen on profits and not caring much about the buyer/tenant's quality of life, you will often find low building quality, in other words, walls and ceiling are of a minimum quality as these flat blocks have often been build within two years or less and satisfy the minimum requirements. No stone walls between flats, just thin layers of woods between rooms etc.
Therefore, to answer your question, a (detached) house is perhaps a better option, at least in most cases in this country.