Advice on design please

[sonolink]

Hello everybody

I am looking for advice and opinions for a friend's project. This friend has bought a small house that roughly measures W3m x L9m x H2.60m. It's inside a patio in Madrid and the only adjacent apartment is along the right 3m wall (picture a 3x9m rectangle in landscape, with a door at the bottom centre and an adjacent appartment on the right). Its one single floor. It's SUPPOSED to be Ground Floor but I have asked him to check with the Council and the blueprints if there's something underneath like a parking or something just in case since I've read many threads about floating floors.

He wants to build a 3 room studio. A Control Room in the centre and 2 rec rooms on the sides. He wants to be able to record drums at least in one room (probably the farthest from the adjacent house). The actual house is made of standard brick (about 15-20 cm thick).

He's asked an acoustics company. They say they would:

1-float all 3 room floors using an "elastic base made of 40 mm thick semirigid panels of high density polyurethane foam (8 kg/m3), covered with a waterproof plastic layer, pouring a reinforced concrete 50mm thick compression layer over that."
(As I understand it the floor will come up about 90mm and each room's floor will be separate having contact only through the present floor)

2-build the 3 rooms on each floating floor with walls and ceilings made of 3 layers of gypsum with different thicknesses (13-19-15mm), screwed to a steel frame with silent blocks on the ceiling, creating a 100mm gap between each room and the house itself, filled with 50kg/m3 rockwool.

I'd like to ask you guys if that seems to make sense as a starting point?

On another hand I think he should use sliding doors to comunicate rooms to maximize space. I've tried to find them here in Spain but they are rare and/or VERY expensive. Any links to plans to get someone to build them or even DIY them?

His total money for the whole thing is around 15.000€

Thanks for your time and help.
Sono

[Soundman2020]

Hey there Sono! It's good to see you back on the forum again! It's been a while....

a small house that roughly measures W3m x L9m x H2.60m.

Are you sure those dimensions are correct? That's about the size of a living room, not an entire house! It is only 27 square meters! Just big enough to build a good control room...

It's SUPPOSED to be Ground Floor but I have asked him to check with the Council and the blueprints if there's something underneath like a parking or something just in case

Smart move!

He wants to build a 3 room studio.

In 27m2? That's too small for three rooms. Maybe two: a control room and an isolation booth. But not three.

He's asked an acoustics company. They say they would:

1-float all 3 room floors using an "elastic base made of 40 mm thick semirigid panels of high density polyurethane foam (8 kg/m3), covered with a waterproof plastic layer, pouring a reinforced concrete 50mm thick compression layer over that."
(As I understand it the floor will come up about 90mm and each room's floor will be separate having contact only through the present floor)

2-build the 3 rooms on each floating floor with walls and ceilings made of 3 layers of gypsum with different thicknesses (13-19-15mm), screwed to a steel frame with silent blocks on the ceiling, creating a 100mm gap between each room and the house itself, filled with 50kg/m3 rockwool.

I'd like to ask you guys if that seems to make sense as a starting point?

It should work, yes, but does he really need so much isolation? Is there something very noisy close by, like a train station, highway, or airport?

His total money for the whole thing is around 15.000€

Then the plan above is out of the question. He would use up all of his budget just for the concrete slabs, without ever getting to the walls. Certainly not the ceiling, the doors, the windows, the HVAC system, the electrical system, or the treatment. The money will be long gone before he can do any of that. He also won't be able to do three rooms with 15 k. Maybe two rooms, with limited isolation, but not three, and certainly not floated.

- Stuart -

[sonolink]

Hi Stuart,
Good to be back and glad you remember me
First I'd like to thank you for your time and advice. I know you're a busy man

Then the plan above is out of the question. He would use up all of his budget just for the concrete slabs, without ever getting to the walls. Certainly not the ceiling, the doors, the windows, the HVAC system, the electrical system, or the treatment. The money will be long gone before he can do any of that.

The acoustics company gave him an estimation for all of the isolation of aprox 15K. Including HVAC system. In any case I'm sure he will find more money for the treatment, gear, etc
We've all been there and done that after all right?

Are you sure those dimensions are correct? That's about the size of a living room, not an entire house! It is only 27 square meters! Just big enough to build a good control room...

Those are rough dimensions. The place is a tiny apartment my friend has inherited from his grandma. The lady used to live in there. Kitchen/bathroom, Living room, Bedroom. It is small but I've seen smaller Personally I think it's feasable for him to have a small production studio where he can record drums if he wants. He would have to mix elsewhere but at least he could work.

My main concern here is to determine if he should float the rooms or not since that means a big difference in money and if sliding doors is a reliable option for sound isolation between rooms and if the isolation starting idea makes sense or is a waste of time and money basically

It should work, yes, but does he really need so much isolation? Is there something very noisy close by, like a train station, highway, or airport?

Not really, the concern for isolation is to avoid problems with neighbours in the adjacent appartment mainly.
The proposition of the acoustics company maybe is over the top?
If the apartment is a real ground floor would NOT floating the floors be an option?

Everybody's suggestions are very welcome.
Thanks a lot for your time and help

Cheers
Sono