I was not thinking of someone using an Altherma hot water heat pump and gas hot water in the same house as that would be a duplication. You are right about many hot water heat pump models being inefficient but the Altherma is a high end unit with a heating COP better than air to air heat pumps in the same kW range. When Daikin upgrades it to R32 it should become more efficient.

 

 

Planitherm is not a single product but a brand collection of low e glasses. Visible light, solar gain and heat retention specifications differ between different Planitherm low e products. Finding out which Planitherm variations are available in New Zealand and what their specifications are would be useful. Specific low e products should be chosen and specified or else the glazer could install anything with the Planitherm name on it.
Overseas it's possible to combine the low e glass with a higher grade of clear glass but that would cost more if it is available.

 

 

I've seen this multi purpose cool drawer product and thought it looked really useful

 

https://www.fisherpaykel.com/nz/kitchen/fridges-freezers/built-in-refrigeration/RB90S64MKIW1/

 

It's very expensive in retail but may be much cheaper through the builder.

 

 

I suggest changing the gas cooktop to this flushmount model

 

https://www.fisherpaykel.com/nz/kitchen/cooking-appliances/cooktops/CG905DWNGACX2/

 

It won't have pots precariously sitting up in the air like their gas on glass models. If the price is unreasonable you could get the very similar Smeg model.