planning and BC: including a close outbuilding as part of "existing dwelling"

I wonder if anyone cares to give an opinion on this. I plan to ask my local planning and BC people but I wanted to get a feel of whether it's going to be straight yes/no or something more grey.
I am going to change the layout at the back of the house (a Victorian end terrace). I am pretty sure this is a permitted development.
1) I want to move the rear single story kitchen wall back 1 metre and add a large area of folding door. 2) I want to demloish an existing (Victorian) outbuilding which is located with a gap of 1.4 metres from the house.
Q) Does the outbuilding count as "part of the house" for building control and planning purposes?
Why is this important? Well, if the ourtbuilding is classed as part of the existing building then the contraints on window and door area resulting from Part L will be easier to satisfy.
I remember that there used to be a rule that any outbuidling within 5m of the house counted as part of the house. Is this still the case?
Other info: Area of outbuidling: 8 sq m., Construction: wood (double skin) with slate roof, built in about 1880 Area of extension of main house: 5 sq m. Window/door area in new wall: 5 sq m.
with thanks to anyone who cares to comment,
Robert
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as it was built well before 1948 (planning act) I strongly suspect it will be deemed to be "original house"
Cheers Jim K
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wibbled on Thursday 17 June 2010 17:19

And the 5m rule is now gone...
--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.
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[Default] On Thu, 17 Jun 2010 07:41:09 -0700 (PDT), a certain
and wrote:

From a Building Control point of view; if you can fit a Rizla between the buildings, they are separate.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
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Thanks everyone. If the 5m rule has indeed gone then this building ir "original" but not part of the house for planing and BC purposes.
Robert
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I still wouldn't knock it down til I've got planning tho ;>)
Jim K
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