Is this a cost efficient / ecological hvac set up?

Hi, First of all, I'm pretty noob in all this and the information that I find on the web and the experiences people tell me about are so divers. I’ve decided to ask my question to you guys, here on reddit. Within a couple of months the construction of my new to build (brick) house in middle-Europe starts. It’s an infill building in an urban environment in a mild climate. Occasionally the temperature drops in winter time to -5 ; - 10° Celcius. But the average is around 4°C in winter time. I’ve been told that I can cut off gas completely by installing an air/water heatpump. To me this sounds very appealing. The idea that I’m totally independent concerning heating. Whatever the source (gas or air) I will be using it for floor-heating and for hot water in the bathroom/kitchen. I read that air/water heatpumps average in ideal situations around COP 4 (coefficient of performance), but people tell me that as soon as it gets colder outside, it will use an electrical pump to generate the pressure and thereby the heat, that’s when the COP drops to around 1 ? The advice I get is mixed, some people tell me it’s just another hype that can’t compete with gas. It’s more expensive to install, it’s high maintenance, … Others tell me to go for it; its ecological, you can’t predict gas prices in the future. What’s the latest on efficiency on these 2016/2017 heatpumps. Which brands are reliable? Daikin? Mitsubishi? And what about installing it in combination with solar panels? Is this the holy grail set-up? Thanks in advance 

submitted by /u/Elho
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