Room Design

Trussed-rafters are a kind of immaculate one-hoss-shay: they can provide large spans out of small-dimension timber, but with zero redundancy. You can't remove any of the members - so to make space for an extension upwards you need to 1) replace the entire ceiling / new upper floor throughout the bungalow, because the lower horizontal members are nowhere near stiff enough to support a floor on their own, and 2) then build an entire new structure to support a new roof... Move house in preference - it would be a lot cheaper & easier.

With the traditional approach of rafters spanning from walls to ridge with an intermediate purlin or two and maybe a couple of diagonal braces in the middle of the whole loft space it's a lot less hassle to make things work. If your house was built more than 20-25years ago, this is probbaly what you have.

Seeing as you have your aunt&uncle to hand I'd get them involved good & early.

Discusison of the best way to detail the upper floor/ceiling/isolation has to follow-on from working-out how big the basic structural problem is - and this involves review of the walls downstairs. But to give some hope - and of course depending on how much upheaval you can stand!- it may be possible to retro-fit a concrete-based upper floor if thats what you decide you want, but it's not necessay to good isolation and in-room response.


(edit: Julian - I'd be happy to answer detail tech queries as best I can via PM if you like.)

 

How about this?

 

nice.

missing a tweeter though?

 

Yes, and it doesn't look time aligned...

 

Midway through building a new room myself here, and hoping that I do have enough height for the 4.8 x 5.7m floor design - nearly 14' seems a bit high for a ceiling!
These places along with a google on listening room dimensions helped a lot, plenty of ideas on construction design and products for soundproofing / flanking measures.
Check out H&H Celcons site for some nice ways to use blocks and engineered timber - great fun to use and work with.
http://www.soundservice.co.uk/index.htm
http://www.customaudiodesigns.co.uk/products.htm
http://www.soundreduction.co.uk/index.php

 

Alternatively, you could save yourself a shed load of money and simply ‘float’ the speakers off the floor with something like Auralex Platfoam. Used a lot in recording studios and to isolate guitar amps on stage, etc. Cheap and easy to install. Astonishingly effective in my experience.