Gap above external window fascia - fill or not bother?

Did someone get their window measurements wrong ?. Normally you allow 5mm tolerance all round.

Personally I would have raised the cill up with cut bricks or blocks and fitted the window flush up against the lintel.

I'd be more concerned with that horizontal crack.

We bought the place from someone who fell out with their builder mid 'refurb'. It's easy to see why. It's a shop so we're less precious about these things than if it was home.

Yeah, that stood out to me too. The place is circa 200 years old though, it would be forgiven for falling apart!

The crack does look if its the mortar line and not through the middle of of bricks.

Has that part of the roof lifted at some time in a storm or strong wind?

I wouldn't be surprised, it gets windy around these parts. I've fashioned myself an office in the eaves recently and it was terrifying last weekend.

Silicone on the outside to seal gaps top and side as for inside it depends on how you want to finish the upper reveal. If the plan is to put the PB on top of the frame then I would fill up the gap between the PB and lintel with PU foam otherwise you will have a cold bridge it would also provide some/extra support for the filler piece which looks like it is only attached by its bottom edge to the window frame. If the plan is to secure the upper reveal to the lintel then a piece of timber secured by screws through the upper frame of the window will allow you to secure a small vertical section of PB coming down to the window frame. For the latter I would consider how you can use the timber to further support the filler piece either screws or capped nails from the outside or double sided tape on the inside.

Richard