5.1 studio - initiating questions

Greetings! Firstly, having stumbled on your forum, I have to say it is superb.I hope I’ve followed the instructions correctly.I think I have... Secondly, I have listed myself as Bolivia as my studio/house project is in Bolivia although I’m currently in the UK. We are currently in the middle of designing a house and I have chosen a space on the top (3rd) floor of the house at the back for use as a studio.I have chosen to work here as the studio will be used not just for mixing and recording but long periods writing and I wanted to have access to the rather stunning view the house has, as well as daylight (not to mention the terrace outside).We’re on the side of a hill up a sleepy road and there’s no facing structure at the back of the house so no predictable sources of loud noise from that direction.It’s just fields til you hit the city which is 12 miles/19km away.Birdsong.The occasional car.The sides are the same.Except there's a goat there.It's quiet and empty.That's the terrain, not the goat. I will be working almost exclusively in 5.1 for the most part and, due to budget restrictions, using a set of stand – or otherwise - mounted nearfield monitors.I would expect at this stage to eventually buy a set of Blue Sky Pro Desk or System Ones, which sounded like my old Dynaudios when I heard them so they seem the obvious choice.The specs say the satelites are dual amped 60W monitors and the sub is 200W. As this would preclude the need for soffit mounts in the control room (unless I’m missing something) I would expect this to radically change the corner designs and angles of the room, so I therefore found it difficult to simply overlay any of the existing 5.1 plans posted on this forum onto my plan.I have tried but all the ones that made sense had wall mounted speakers as part of the design.So I have stolen and adapted the image posted on this thread : viewtopic.php?t=9493 which is about the closest I have found to the kind of thing I had in mind,(in fact it might be quite good - I'm beginning to really like it) but the monitors will be stand/bridge mounted nearfields.Whoever designed this, thank you. I have more space than the original recipient of the design had and would like the room to utilise as much of the 6.4m width I have.I have enlarged a cut out of the design which I have superimposed and enlarged to fit the space I want to use.I didn’t copy the exterior walls as they were from a pre-existing building.I can build mine how I want so it's best to custom design them. I originally faced the control room longways, with the terrace on it’s righthand side, but decided, as I want large windows/patio doors, that they should be behind the monitors as opposed to being on one side, unbalancing the acoustics.The Who’s old studio in West London had the same thing behind the desk, with a view out onto the Thames.It didn’t make the room unusable by any stretch though there was a gap of a few feet behind the desk/nearfields, I recall. The original 5.1 control room image I nicked is posted on top of the enlarged version with the sweet spot in alignment with it.I would be tempted to extend the monitors back along the axes toward the walls to increase the working space between them. The original image seems, fortunately, to be at the same original scale as my architect’s plan (or as near as dammit) so it has helped to give a sense of detailed perspective.I have endeavoured to keep the enlarged version to the same proportions as the original for reasons obvious even to me.Unless of course I’m completely wrong, in which case….god knows. Apart from the 5.1 control room I will need to build a smaller tracking room to record guitars, vocals and sundry acoustic instruments.No drums or full bands or anything. All the floors in the house are to be built of reinforced concrete (concrete slabs with iron spines running through them) which, I’m told, are standard issue and so would be about a foot and a half/0.5m thick if they’re like the myriad house constructions I’ve seen in Bolivia, which looked to me as though they all use the same spec’ed materials.I’m currently awaiting a more precise measurement of the thickness from the architect but it may take time. The walls of the house will all be built from either brick or stone and the walls for the studio – both inner and outer – can also be built from these materials – or concrete. My instinct (and common sense) tells me it's best to build correctly shaped double walls from either brick, stone or concrete first off and then use acoustic treatment only to iron out surviving problems and interior acoustics as opposed to building outer stone/brick walls and then making separate studded interior walls.Perhaps that’s wrong, although I’ve been in commercial studios where the inner and outer walls were both brick (they were very thick, admittedly, but then although they were recording drums and orchestras there, the principle would still hold, wouldn’t it?) Due to the lowish sound levels from both inside and outside the studio (I'll be making do with just nearfield monitors and I almost never work loud) I’m hoping this may be a realistic proposition. It is far from finalised as to which walls will be made of which material through the house (brick/stone) and at this stage any decisions about studio materials can therefore take precedence over the rest of the house due to the critical nature of their role, although I have been told by the architect that he has worries about the weight of using an excessive amount of stone overall in the house due to weight issues. The bricks in Bolivia are standard kiln fired bricks, not the other kind used by the likes of Albini at Electrical Audio.I know this categorically because I have asked.They are basically standard issue solid red bricks.If stone is used, it would be local Andean mountain stone cemented together.It’s going to be hard to be more specific than that about it, I’m afraid, unless it’s type is of crucial importance because it will be hard to find out in advance due to the informal nature of the ‘stone masonry’ market in Bolivia. You tend to buy the stuff by the truck out there.And they’re usually parked at the side of the road. The ceiling height assumed by our architect on the drafts shows 2.9m but that is just his original assumption.It can be ignored, i.e. extended upwards as it’s the top floor. And so; I have modified the architect’s extant plan for the 3rd floor. The potential studio space is 6.4m wide and 11m long (top to bottom as you look at the plan).Area B cuts into it.The area is therefore 70.4msq -7.2msq = 63.2msq. As it stands, it seems to me natural to make the part of the studio adjacent to B (at the top of the plan as we look at it) the tracking room and have the rest as a control room. The entrance to the studio area is via the bridge (puente), from the left. Space labelled A is an empty space.(It is a cut through right down to the basement to let light in from above).The bridge below it (the ‘puente’) will be made of wood unless I’m told acoustic concerns dictate otherwise. B is another cut through for the same reason.Neither A or B can be changed without radically redesigning the plans for the rest of the house. C is a terrace overlooking the view which cuts a path behind the studio to connect with the rest of the floor this needs to remain in place.The back terrace (C) can be cut into further if need be. D is a sloping roof from the floor below. E is another cut through to let light down. F is a proposed chimney stack. If this is likely to cause a problem through the 2 brick/stone studio walls I would opt to build then it will move.I suspect it might.(The architect put it there honest guv :-) ). I’ve coloured the wall to the right of the Studio Space red because it is really the only one of it’s outer walls that could move about if needed.C,D and F can all be eaten into. As it faces the view, I would like to find a way to allow a decent amount of light in from this direction, so I have started from the point of having bay sized window/s on this side. Their benefits are too obvious to be ignored out of hand, given the location, (psychological if nothing else). I hope I've not left anything out. So, in short, I guess I'm really asking 2 questions. The first, which is why I'm posting this with the design threads, is the shape of the rooms (the shape of the tracking room, I realise, is more arbitrary than that of the control room). The second is about the build: Is it better, or as good, to build dual brick/concrete/stone walls (but incorporating any internal treatments they may need) for the studio and leave other acoustic treatments to deal with what I hope would be more minor or supplementary issues, primarily relating to acoustics (absorbency, diffusion, etc)? I can only post this in one place, so this is the question that would ideally be somewhere else – apologies for that. I hope this covers everything.Apologies in advance if not. Ian.