External insulation and new extension

pattwoie

Planning on significant renovations and extension to a 3-bed semi-d from 1950s in Artane, Dublin.
Includes 30 sqm extension to rear of house.
Planning on external insulation of existing house using 120 mm of Kingspan Thermawall TW53.

Question is how to tie this with existing house:
1. Do extension in normal cavity wall construction with insulation in cavity - different to plans for existing part off house
2. Do block wall (on flat) with external insulation - similar to plans for existing part off house
3. Other

One concern with doing external on extension (2) is fact one wall is very close to boundary wall
of neighbour (neighbour also has an extension).
Worry of architect technician we're using is
A. How to avoid cold bridges and
B. if adding of external insulation to wall closest to boundary wall is physically possible due to lack of access

Any advice would be much appreciated.

BryanF

What's the boundary construction?

Calahonda52

A variant of this was up earlier this year.
The view was to go EWI all the way, new and old.
In you case move the boundary wall in far enough to allow it be EWI'd and live with the thermal bridge, perhaps dry wall internally on the corner

pattwoie

BryanF wrote: »

What's the boundary construction?

4" block on edge I think. Very basic boundary wall.

pattwoie

Calahonda52 wrote: »

A variant of this was up earlier this year.
The view was to go EWI all the way, new and old.
In you case move the boundary wall in far enough to allow it be EWI'd and live with the thermal bridge, perhaps dry wall internally on the corner

Is this the one you were referring to?
New ish user so can't post a link yet so here my attempt around it
boards.ie/thread/2057374665/1

Thanks for the pointer.
Hadn't found it in my earlier search.
From that it looks like extension should be block on flat with EWI on both new and old