6m rear extension roof advice

[webdug]

Hi,

We're trying to do the planning application for a rear extension ourselves, to save a little on costs.

Our house width is ~5m. We are an end of terrace. I'd like some advice on what is possible.

What we'd like is a gable style pitched roof (I don't know the real technical term for it) something like this:

https://www.21against.com/image/21a...n-family-room-bifolding-doors-o-736-x-500.jpg

If you can't view the picture, it's the inverted V style roof.

This gives us an option of more than two roof lights. But I'm worried about the pitch of the roof. We can go up to about 4m before we hit the bottom of our 2nd floor windows. We were thinking the eaves height would be 3m, but that only gives us a raise of 1m extra leading to a very low angle of pitch = inv tan (1 / 3) = 21.8 degrees. Can someone advise what the recommended pitch angle is for this style roof? Should we be lowering the eaves and if so, to what?

Our other options are flat roof or a pitch to flat (eg here: https://www.diynot.com/diy/media/untitled.88360/)

We'd appreciate advice.

Additional question, should I stop trying to save the money and involve the architect at this stage (we're planning on involving one if planning is approved).

Thanks

 

[tony1851]

To put rooflights in, you generally need a pitch of around 15°; there are some tiles which do a fairly low pitch (Marley Moderns go down to 17.5°)
(BTW, don't bother getting an architect in to do the drawings unless you want to raise a second mortgage to pay for generally crap service).

 

[Notch7]

Have you thought about a flat roof with a lantern.

There are plenty of contemporary styles possible

 

[webdug]

To put rooflights in, you generally need a pitch of around 15°; there are some tiles which do a fairly low pitch (Marley Moderns go down to 17.5°)
(BTW, don't bother getting an architect in to do the drawings unless you want to raise a second mortgage to pay for generally crap service).

Thank you. Are the lower pitch tiles pricier?

 

[webdug]

Have you thought about a flat roof with a lantern.

There are plenty of contemporary styles possible

Hmm, I had a look and not sure I like the style. It does let in a lot of light but you lose the high internal ceilings. Also, it looks pricey.

 

[ivixor]

The opposite actually. You can have a flat roof at any height you like! The flat roof can come out just below first floor window level and you'll have hugely high ceilings.

 

[Bonni]

One thing is certain, flat roofs leak.

Mendip interlocking tiles will do down to 15 degrees.

 

[ivixor]

Not remotely true. Maybe you're thinking of bits of felt from 30 years ago? Technology has moved on since then.

 

[Notch7]

One thing is certain, flat roofs leak.

Mendip interlocking tiles will do down to 15 degrees.

I doubt if flat roofs leak any more than pitched roofs.

It might have been true a lkng time ago. Now there are various flat roof systems with a very long life span. GRP, single ply, epdm, liquid coating.