always put water in the bucket first add the thinset powder on top of it. put the drill paddle to the very bottom of the bucket and mix. do this until thoroughly mixed about 4 min and then let it sit for a few minutes and mix again for another 30 sec to a minI prefer mixing as opposed to purchasing ready mix. first of all the ready mix is more expensive and to me it is much harder to handle. tip 5 organize your work area.preparing the area.  

Gas or heat pump, maybe a mini-split might make sense to consider. 

This site truly can be likened to a mini RE course.

I heard of gas mini split systems that can be installed and installation costs might be much cheaper and the systems are supposed to be efficient by mitsubishi. 

I don't know how good your german is already but you can find lots of useful information there (a bit like a mini bigger pockets for Germany).

So I am currently involved in purchasing a property that I intend to open a mini storage location.

I have plastic mini blinds and curtain rods at each window but I did live in the house before turning it into a rental. 

Depending on the size and floor layout of the units, you could replace the central system with in-unit air-exchanger and/or {mini-split} heat pump.  

Mobile home parks, self-storage, mini-storage are not frothy and you can really make your cash stretch and use leverage to acquire as many as 30 pads in mobile home parks, or more.

Same with mini-blinds and verticals; tenants always seem to break these so buy the cheaper brand and be prepared to just change them out.