Howes and Howse are frequently interchangeable and in the West of England you'll often find House too. Although most families have now settled upon a single variant, that wasn't the case in the past.
Do take a gander at my (non-commercial) website dedicated to the Howes, Howse, Hows and House names. I just checked my online database and there are at least 5 Howses in Alveston, 9 Howeses in Olveston, 9 (mixed) in Oldbury and 23 in Thornbury. There may be a little overlap in the case of people who lived in both locations.
Good luck with your search.
Paul
howesfamilies.com