Building regulations/sound insulation

[dom]

I'm converting an old chapel to a home, and this morning re-read the requirements of the Building Regs (part E), Sound Insulation:

the minimum legal requirement is section 5 for internal walls (p60-62).

In my case: Internal wall type B (diagram 5-2, p61) - single layer of plasterboard either side of studding, with mineral wool quilt in between (subject to minimum dimensions & weights etc.). Internal floor type C (diagram 5-7, p62) - solid timber joists with t&g boards above and single layer of plasterboard below, with mineral wool quilt in between (subject to minimum dimensions & weights etc.).

However, what I propose to do is use elements of the approved document's design from sections 2 & 3 (Separating walls and floors, new buildings)

Internal walls type 4.1c (Diagram 2-37, p36), with 2 physically separated layers of studwork, mineral wool, but single layer plasteboard (slightly increased weight, approx double thickness cw legal requirements) Internal floors type 3.1A (Diagram 3-20, p49), with studwork suspended beneath the joists to carry the plasterboard and mineral wool carried by netting stapled to the underside of the joists (again slightly increased weight, approx 50% greater thickness cw legal requirements - but an unobstructed void throughout!)

My main reason for doing this is I have lots of space (particularly height), and thicker walls and ceilings are not a problem, but I DO have a problem with routing services (building layout, solid outer walls & the roof design) - and want to run all the services in the first floor void.

The internal layout of rooms is also unusual (ground floor bedrooms below first-floor open-plan lounge area) so that increased sound insulation particularly in floors is probably wise.

AFAICS the voids would meet the minimum distance requirements for electrical cables to be freely routed, and plastic plumbing and heating would be very easy to route in continuous runs around various level changes on the upper floor (0.6 and 1.2m, required to negotiate oddly positioned windows).

I appreciate this is a very geeky and specific question - but can anyone identify other downsides to my proposal that I may not have thought of - other than the increased thickness of floor and wall chords?

[Owain]

You can get metal /\/\/\/ sections that go between floor and ceiling joists and allow services to be run, might be easier than suspended studwork.

Especially if you are having solid floor upstairs in the living area, you might also want to look at having the 'decorative' floor floating on a layer of foam or something, above the structural floor.

Also don't neglect nice hefty well-fitting doors.

I think thicker walls look far better especially in older properties.

Owain