To heat or not to heat...

After speaking to Seamus from http://viking-house.ie I am inspired and even more confused. After much thought I had settled for substandard passive house insulation, an exhaust air source heat pump with integrated water store and a woodstove with backboiler. The system would need a MVHR (Multi Vent Heat Recovery) system to supply the house with preheated fresh air.
As I am still trying to save money I looked into the whole MVHR system as it's pricey and needs a lot of ducting running around the house which will cost time and money to install.
I found these very interesting units called FiWi HRV (Fine Wire Heat Recovery Ventilation), that work without ducting, on the Viking House web page.

Only two of them are needed to ventilate our house. This should work out considerably cheaper than the MVHR. However, I will need to scrap the heat pump, rethink my insulation and heating needs and construct a thermal slab, get a thermal store, a load of solar thermal panels and life happily ever after....
...if i had triple glazing :-(
Why is being green so bl**dy expensive ???