adjoining semi

[goddessmunch]

we are currently having our 1930s semi detatched house completley re-rendered and pebble dashed.our single storey kitchen extension juts out about 2 feet further than our adjoining neighbours newly built double storey extension. our neighbour has complaines that our builder has not done any work on the 2 foot wide strip that juts out and is on her side, i say she should maintain the finish of that wall since is it on her side but my husband says it is our reponsibility since it is our wall, who is right ?