House Renovation Concept

The Northern Territory in Australia is hot, all the time. We have a 1970's elevated, three bedroom, two bathroom house on 1000sqm block. We are a family of five (kids are 11, 9 and 6) and so we're wanting to extend the house, but we're having trouble getting all of our ideas into a workable solution. We're finding that the local designers that we've spoken to have been a bit uninspired, and expensive. We are looking for an architect/designer to build a 3D conceptual design that hopefully encapsulates most or all of our ideas, that we can take to a local engineer. We have a list of 'must-have's', and some 'nice-to-have's.' Must haves: A new master bedroom with en-suite and walk-in robe A large study/office, big enough for two people A downstairs toilet A downstairs kitchen Internal stairs Nice-to-have's: Gym/Yoga room Car garage/workshop (to work on a classic car restoration project) An fifth, guest bedroom Extra lounge/cinema room (we want to remove the TV from the current shared living space) Undercover outdoor entertainment area Other things to consider: We would like lots of natural light, but given the intense heat in the NT, we need to avoid large windows that let direct light in, and no sky-lights etc, it's just too hot. We live in the Tropics so we would like the house to take advantage of the beautiful weather in the Dry Season, and be enclosed and air-con'd in the unbearably hot Wet Season. All windows should be louver style because in the Dry Season we would want take advantage of the cooler breeze. The back of the house looks out on to a golf course. We would like to make sure the main features of the house can take advantage of the view. Every space will need air-con and ceiling fans Large eaves would be handy so we can leave louvers open in the (light) rain without water getting in through the windows. Underneath the house is partially built in with a laundry and store room, but we're not adverse to demolishing those rooms. The house has large verandas front and back and while we would like to maintain some outdoor space on both, we're not adverse to partially building those in. We have a big caravan which we think would fit nicely to the left of the house if we removed/moved the existing shed. Sunrise is at the rear right of the house, and sunset is the front right. We get amazing sunrises and sunsets here so we would like to make sure we have an outdoor area, maybe the verandas, where we can still watch the rises and sets. I have attached a few photos and Google Earth view of the block but I am happy to add videos or more photos if required. I will provide our address when I am confident I am talking to a genuine applicant for the project.