What's wrong with a SIP extension (self build)?

[Apache]

My project really has two halves - an old stone 'barn' that will be converted to living accommodation downstairs with 2 en suite baths upstairs. I have a SIP extension planned. That will have a large kitchen downstairs with a few small rooms at the back. Upstairs will be two good-sized bedrooms for my boys. 

 

Spoke with a few people, local builder, 'architect' although he does drawings and planning he's strictly not. All were favourable. The builders' son (also a builder) lives in a SIP house. 

 

The appeal for me - doing as much as I can self build. In a short period of time a structure appears that I then finish off. Cost seems favorable. It feels like a much 'easier' method of building, for me, than traditional block/stone. Even having a solid surface of roof to clad feels appealing.

 

@Nickfromwales seems to think I'm mad.

 

Born and bred in Yorkshire, have a thick skin. Tell me how it is. 

 

Thanks

[Nickfromwales]

19 minutes ago, Apache said:

@Nickfromwales "seems to think I'm mad........

.....to not explore all of my options before parting with my life savings".

 

End quote   

 

19 minutes ago, Apache said:

Born and bred in Yorkshire, have a thick skin. Tell me how it is. 

Game on

 

[saveasteading]

1 hour ago, Apache said:

doing as much as I can self build

That to me is decent justification. A kit reduces risk for the beginner, just don't try to change anything from a proven form.

It depends on more than that though. Geometry, the ground and topography, how it links to the existing...and more.