Normally a hot tub comes with a means of heating the water, and maintaining it without having to empty the water. This is where water filtration and disinfection methods are worth it and less wasteful. It really doesn't matter whether it is stainless steel or not: you are heating up water to levels that naturally promote bacteria and algae. Hence the NEED for some type of disinfection - which can range from tossing in a chlorine table to add ozone or other types. I suggest you purchase a book entitled "What colour is Your Swimming Pool" 2003 edition. It will give you a practical guide to what you are looking for to maintain your spa tub and why you need to do it.

I do like the tiles... however I suggest you give a think about the future cleaning of the grouting before you commit. Near a spa, the moisture in the air is a breeding ground for algae and mould.

I can't get the picture to blow up big enough to see much , but unless you are running a backpackers , I would suggest 1 bathroom for 3 bedrooms would be all you need , in fact unless you are having a 'grannie flat' or similar built in , I would think that 2 bathrooms and a 3rd powder room with its own handbasin would be all you really need . Of course , more is more luxurious , so having a second ensuite is good , having a shower and WC in every room has advanatages , mind you so does having another with a bath and twin showers , 3 seperate WC's in case you have 100 people visit , a seperate spa room with its own shower and toilet , a sauna , an outside pool with its own male and female changing rooms with showers -- in other words , do what YOU want once you get past the basics . And I'm not a fan of two doors from 2 bedrooms into a bathroom -- especially if there is a bath or shower and a toilet -- it relies on everyone working together , but also on everyone pushing the right combo of locks so that there's no accidental walking in on someone .

My suggestion -- start with a 'base' -- do the fence in charcoal , the retaining wall almost looks brick but I'm guessing it is wood , so maybe go the same grey as that tank wall or whatever it is , and do the white pipe the same ? And then decide the purpose -- a bbq , a table and chairs , a love swing , a spa pool , a water feature , a traditional garden , a rock garden , a desert scene , an egyptian garden -- you get the idea . One or all of those , or whatever suits YOU .