Redesign of bungalow and extension

metricspaces

What would be the rough costs to transform the bungalow on the left into the one on the right (see picture below)?

In terms of costs, I'm looking to get a figure just for a builders finish - no kitchen installed, no bathroom furniture fitted, no floor coverings.

Some key points:

• Based in North County Dublin
• Existing bungalow is 66sqm
• New extension is 33sqm
  
• Existing bungalow has a poorly constructed flat roof extension that needs to be demolished
• The redesign involves knocking internal walls. No idea if they are load bearing, so let's assume they are and steel is required to achieve the open plan living room\kitchen area.
• The bungalow is mid-terraced. But there is a lane way to the left of it. The roof actually goes over the lane-way.
  
• Existing house will need insulation in walls - lining from outside.
  
• Assume original house does not need rewiring
• All new windows\doors throughout - assume double glazing PVC (munster joinery)
• Current heating system is oil. Assume stays same.

If I take a rough figure of 1.5k sqm for new extension. That's approx 50k
Then for the reconfiguration of the existing 66sqm? No idea, but I guess the main costs will be:
1. Erecting steel to replace load bearing walls
2. Relocating services for kitchen (currently in the existing extension)
3. Relocating services for bathroom (into extension)
4. Insulating walls

metricspaces

Any thoughts on costs here? Would appreciate any stabs at it.

Gumbo

add on 1k per sq.m for the existing house.

Will give you an idea but you really should be getting detailed quotes from contractors.

jmBuildExt

+~10k for your external insulation.