Concrete cills with uPVC windows

[sueonmull]

We are having an extension built. The uPVC windows ordered by the builder already have cills. Do we still need to use the precast concrete cills that have been included on the plans approved by building control?
I will speak to building control direct but just wanted some background advice first.
Thanks
Sue

 

[Alastairreid]

Yes you will still require the concrete cills as specified in your plans.
whether building control allows you to omit the cills or not remains to be seen, but it is a much better job with proper structural cills.

 

[noseall]

The uPVC windows ordered by the builder already have cills. Do we still need to use the precast concrete cills that have been included on the plans

No you don't need to use concrete sills if you don't want to.

They were probably included on the drawing to match existing? Your builder has probably quoted for these also. They serve a practical purpose in the same way as a plastic integrated sill would, but offer a far better match aesthetically should the existing building have them.

There may be a planning aspect here though with conditions that encourage you to match the existing building where applicable.

 

[Alastairreid]

overview. side elevation.

• Alastairreid
• 15 Dec 2008
• 3

the external work is complete.......

far better witrh cills!

 

[noseall]

far better witrh cills!

Yes alistair quite so.

As i said, only one sill is needed, whether that be an independently fitted masonry sill or one that is integrated into the window itself.

 

[dave1953]

mm! does someones level need a new bubble

 

[Alastairreid]

mm! does someones level need a new bubble

 

[dave1953]

There is a hump in the middle of the cill

 

[Alastairreid]

lol no there aint........its a bit of rubbish or something under the pvc..........right i'm off to make sure...........

 

[noseall]

There is a hump in the middle of the cill

I see no hump?

 

[Alastairreid]

nope deffo no hump its....................humpless

 

[sueonmull]

Thanks for all the replies.
Our extension is being built onto a stone cottage with 2' thick walls, the extension will be rendered and painted to match the rest of the house. The way the extension is positioned the new windows cannot be seen at the same time as any existing ones but anyway existing windows only have cills that are part of the window frame. The windows in the extension are going to look really odd having both the window's own cill and a pre-cast cill underneath and perhaps even worse when they're rendered and painted. I will give building control a ring tomorrow now I know I'm not asking for anything stupid and see what they say.
Thanks again
Sue
PS we live on the west coast of Scotland so don't think too badly of us using PVC windows, they really are much more practical and they do look good - honest!

 

[Alastairreid]

PS we live on the west coast of Scotland

Me to .........not as far as mull though..

 

[noseall]

You won't get much from bc i'm afraid, planning is your best bet.

As you rightly say, two sets of sills looks wrong.

You either use upvc widows with no sills or stub sills and incorporate the masonry sill...

...or use full upvc integrated sills without the pre-cast masonry fellas.

 

[sueonmull]

Thanks to everyone
I spoke to the builder this morning and he wants to use the pre-cast cills to close the cavity. He understand my concerns but I think we're going to be stuck with it - doesn't help that everything is quite a way behind schedule and we can't afford to hold things up.
Hopefully when the cills are painted it won't look too bad, just wish we'd been aware sooner and could have made sure the windows didn't have sills.