Building Warrant Plans - Velux

[Rainking79]

Hi all,

im planning on installing a Velux but need to submit plans for a Building Warrant (Scotland).

I'd need to cut one rafter to create the space needed in the roof plus one bottom rafter (to flow into downstairs bathroom).

Has anyone submitted plans for this work before they could share as an example for me to copy? I've done a 2D of the fink as is with sizes but feel im over-thinking how many views are needed r.e. 3D of the cut rafters with new headers.

At 60 centers the cut gap width would be <4ft so I don't 'believe' I need to double the rafters but happy to be schooled

Thanks in advance

 

[catlad]

I've found it depends on your building inspector! old or new! You don't mention rafter dimensions.

 

[Rainking79]

I've found it depends on your building inspector! old or new! You don't mention rafter dimensions.

Very true!

They are 34mm x 67mm (70's build).

 

[Rainking79]

I've been (unsuccessfully) trying to obtain the services of a SE for the above work - I, perhaps mistakenly, thought they could do the drawings with the necessary reinforcements required. The last two have mentioned they'd need an architects drawings, even if they had the time to help me.

Can someone advise should I be looking for an architect to draw the rafters with the cuts for the window? Would an SE then calculate if what they've done would be strong enough? I'm confused as to what everyone's role should be help me get on with this.

So close to just cracking on with the job - doing it the right way isn't getting me anywhere

 

[noseall]

The last two have mentioned they'd need an architects drawings, even if they had the time to help me.

They're just being lazy. I've had to do loads of grunt work for SE's. I suppose it's cheaper for me to go and lift carpets and floor boards, than them.

 

[Rainking79]

I’ve spent most the of the night trying to learn what i need in Sketchup. I’ve got a set of trusses at 600c, so marginal gains

Just going to need to take my best punt on the warrant and hope for the best.

If anyone has BW samples they could share it would be most appreciated.

 

[^woody^]

Don't you have a building notice route in Scotland, where you can submit an application without needing a drawing?

This is pretty standard work that should not need a drawing or calculations. The concept is that if you double up the rafters each side of the removed rafter and trim the cut rafter, then this greatly compensates for the missing rafter and so does not need to be proved by calculation.

 

[Rainking79]

Don't you have a building notice route in Scotland, where you can submit an application without needing a drawing?

This is pretty standard work that should not need a drawing or calculations. The concept is that if you double up the rafters each side of the removed rafter and trim the cut rafter, then this greatly compensates for the missing rafter and so does not need to be proved by calculation.

This would be the dream but unfortunately I don't believe we do.

Guidance on needing warrant says "If you're not sure whether you need to apply for a Building Warrant you can ask your local council's Building Standards service.".

They replied to me with "Unfortunately, due to the many variations of building works, we cannot say for certain if your proposals will or will not require a Building Warrant.". Talk about the runaround

They have warrant guidance that does say "Altering roofs, external walls or other structural elements" requires a warrant. TBH, im not sure if the submission needs to contain drawings/calcs or not, and was hoping someone on here had been down that road already.

Current thinking is to submit my own drawings, like you say including trimmers, and see what happens. I'm hoping, as you say, they see it as standard and need no further calcs but I guess it'll all depend on the inspector

 

[^woody^]

Drawings can be simple.

 

[Rainking79]

Awesome - thanks Woody. This is exactly what I had in mind, so could submit this as is

I'll share my version, for posterity and any feedback

 

[^woody^]

so could submit this as is

I'll let my insurers know.

 

[Rainking79]

 

[Rainking79]

I've attached my effort. I didnt do a drawing for the double-header installation as I ran out for motivation by then

Hoping to get it submitted tomorrow with fingers crossed.

All comments welcome/encouraged

 

[^woody^]

One issue ... those are trusses not rafters!

Whilst it may be OK, trusses are not designed to be cut or support point loads such as trimmers.

See how you go, but the inspector may ask for design calculations.

What is happening with the diagonal truss bracing? Is that affected?

 

[Rainking79]

One issue ... those are trusses not rafters!

Whilst it may be OK, trusses are not designed to be cut or support point loads such as trimmers.

See how you go, but the inspector may ask for design calculations.

What is happening with the diagonal truss bracing? Is that affected?

I thought top of a truss was a rafter (?)

I need to remove the short diagonal on one truss, to make the space on the roof. I don't have anything built in specifically for that being removed, if that's what you mean. Are you thinking like putting in a vertical support (below)?

Really don't want to go back down that Architect/SE road again - was just about the end of me