Thanks :) Yeah decided to go with tile. So sand cement is ok over existing tiles if I prep them first? Only problem is, the new pad can only be about 30mm at it's thickest (leaving up to 15mm for tiles) otherwise it'll end up being higher than the hallway floor. So I either need to make the fall shallower or not bother with the waste and make it all level. If I made it level, could I use levelling compound at that thickness or would deck mud/sand cement be the best option? Also, should I be putting in mesh for strength? (I know I should (and will) ask the local hardware what they suggest, but it's great to have suggestions from the Houzz community also)

Having only 4 feet above your face sounds tight to me. Guess you could have a couple of people hold a thin piece of plywood at that height as you lay on the floor. Think I would move the doggie den somewhere else and use a couple of those feet for the sleepers.

Hi Joanna, There is a lot of different options to make this work for you. The landscaper is correct that you can have pavers under the spa. Typically in this situation we would pour a reinforced concrete pad to create the foundation and then wet lay the desired paver over the top. As long as the pavers have a solid base underneath them there shouldn't be any issues. Removing the timber retaining will definitely open up more space although correctly planting this could also create a great nestled in area and make it a great feature. As far as choosing the right paver for the space it probably has more to do with the house and the other areas. One option is getting a paver that contrasts with the cladding on your house and is similar to your joinery / roof colour. Have a look at www.urbanpaving.co.nz for some options, depending on budget I would either look at the Sandy textured coloured pavers or a natural stone option. Thanks, Will

You DO have a steep slope to deal with! The tree roots will help stabilize the soil and make a mudslide less likely. If you cannot mow the lawn safely, terrace the area (think Machu Pichu) into garden beds for flowers or vegetables. Do you want your children to play on a grassy area or on a man-made surface? Be sure that the play area has shade during the hottest part of the day. Best wishes.