I have just checked all 1,142 residents of Bute Street, Cardiff in the 1881 census and there's no entry for 174. As the OP said, the nearest abode is 175 which is the first entry at the top of page 90 of RG11/5280/144 with the schedule number 462. The last entry on the previous page is schedule number 461 and is 26 Francis Street. Francis Street does not appear to exist today so it's hard to work out what route the enumerator might have followed. I also didn't find any houses in the low 160s or 170s Bute Street, suggesting that either they didn't exist in 1881 or that indeed a few pages are missing.