Dormers nearly but not touching - rules around it

[Shlumaan]

Hello, we're in the process of converting our loft, it's a hip to gable conversion at end of terrace. Our neighbours who is lovely with him we are on very good terms has signed the PW agreement but as they had their loft converted 10y ago he has expressed some concerns regarding the proximity at which our dormer has been placed. On inspection I noticed that my new dormer is literally 1cm or less but not touching their dormer and while theirs was tiled ours isn't tiled understandably due to lack of access but our builders have placed some white fireproof boards between the dormers. I also noticed that our roofs somehow cover this minor gap and it should be water tight. However my neighbors' concern is the lack of airflow and potential damp in both our walls down the line and my main concern is twofold: 1.does building regulation permit this proximity between dormers 2. Is my lack of tiles on this side in anyway a disadvantage?

I would appreciate some insight into this scenario both legally and from quality control side of things. Last I would add that we are converting our loft with a big reputable company who know their stuff, so I'd be really surprised if they breached any regulations.

Thanks

 

[^woody^]

Legally - construction should prevent fire spread across the boundary, and roof to be weather tight.

Quality - detailing and materials to be suitable for long term performance with no maintenance.

No air flow and damp is not a concern as the detailing and design deals with that. No need to tile.

Ensure your "fireproof boards" are suitable for external exposed use. and that all joints are sealed for weather and fire. The fire resistance requirement includes the roof and fascia etc within 1m of the boundary

 

[Shlumaan]

Thanks that's really helpful.

 

[Shlumaan]

I've got a new situation as a result of the two dormers being so close to each other. The roofers applied lead flashing to close off the gap between the two dormers only that they've applied the flashing on top of my neighbours tiles (without even asking!). Understandably my neighbour is really upset. The company says there is no other way to make it water tight. Half of the problem is the lack of communication. I'm sure my lovely neighbour would have showed some flexibility had he been asked and explained in advance. We've got a meeting on Monday with the company and my neighbour will be present too. I want to know if there is any other aesthetic finish to closing the off the gap that wil cover the flashing. The roofers said they couldn't put tiles on top of the flashing. See photo attached. Also, how are these matters handled between neighbours and loft companies. Did they have to go over his row of tiles.? Any thoughts would help.