I am planning on building a 2 room garden studio. One of the rooms will be the main control room and the other will be a small kitchenette area.
Any recording will happen in the main control room area. The control room will be 4.5M X 4.8M . The kitchen area will be 1.25M X 4.8M. the one and only door entering the building will open into the kitchen area which will also act as a sound lock. Leadings off from the kitchen (to the left) will be an internal door to the main room
I will use the studio for composing, mixing and recording (vocals and acoustic instruments such as acoustic guitar, violin, banjo etc). I record full drum kit about 2 or 3 times a year for perhaps a day each time. My usage level is about 80 - 90 DB when mixing. I don’t really work in bass heavy music
The studio will be 15 meters from the nearest neighbours property. I live in a quiet suburban cul de sac - no passing traffic
I’m in London (UK) and I am keen to keep the build within what is know here as’ permitted development’ - basically (as many of you will know ) - you don’t require any planning permission as long as the eaves height of the build does not exceed 2.5m. If it is a dual pitched roof (mine will be) then the top of the roof can go as high as 4m, but the eaves can go no higher than 2.5m
EXTERNAL WALLS : Each of the 4 exterior walls will be made from 2 layers of block (1 of the layers will be concrete block the other some other kind of masonary block so that they don’t resonate together) - I plan to fill the cavity between each layer with insulation.
I think the exterior walls are fine for STC… BUT my main concern is the roof and whether that matches up to the STC of the walls (I’ve read that the roof/ceiling is like a ‘5th wall’). I’ve read in (Rod Gervais book I think) that if the roof/ceiling is weak then not much point having mass walls - ie, only as strong the weakest link etc To stay within the height limit (2.5m to the eaves) I have limited space —so for the ceiling I am considering using beam and block for the mass which block and beam has (the beams resting on the cavity walls will take it to the 2.5m limit) from that point I am planning a dual pitched roof - slates perhaps.
My plan is to ‘close up’ (ie, ‘finish’) the main building first and from that point test what sound leakage is like and sound proof according to the measurements so as to get enough soundproofing for what I need but no more than is needed (considering the cost of soundproofing etc) . For clarification —> by ‘close up the building ‘ I mean get the concrete foundations done /block walls constructed., ceiling and roof constructed as well as all the doors and windows fitted. Ie, the building will be basically built with bare block walls inside . I will get acoustic doors with great STC likewise and an acoustic window with also great STC. Does this sound like a good way of proceeding? !! Ie, build the main build first and then test DB leakage to see what internal soundproofing needed. Obviously I really want to get the design/construction of the main build as good as can be and still keep within the 2.5m height to eaves limit.
My main question is - What s the best ceiling/roof to have considering that I have double layer concrete block walls but limited height ? I really want to get the main build right ! I’m new-ish to acoustics /studio building so any help really appreciated. Thank you for your help- very very much appreciated. There are some real experts on here - hope I’m not asking real novice/newbie questions!! Thank You