Home DIY

We have a dark middle room and are looking to bring some light in. Don't want to go full window, because external wall faces back of adjacent property and likely to encounter grumbles. Also, don't want to get into lintels etc.

So thought about adding some porthole / very small transom windows up high, but not sure about a few things:

• what size hole could we make in the victorian double-brick wall without needing to add lintels, etc.?
  
• whether (modern) glass bricks could be used - and if so, how do they perform thermally / is condensation a concern?
  
• whether there are any suitable double-glazed units that could fit the job (everything I've seen is relatively large)?
  
  

Any thoughts gratefully appreciated...