double glazed door/window-best relative glass thickness?

hello, I am having a wood framed practice/recording room built in garden (as we speak!). I am at the point of configuring a double glazed external door and window. I have found a company here in the UK (www.modernupvcwindows.co.uk) who can make these up with a choice of glass thicknesses. They can either make both panes of laminated acoustic glass (pilkington optithon) or one pane as above and the other thermal laminated glass (pilkington K glass). The glass thicknesses they can use are either 8.8mm or 6.4mm. By studying this forum i have understood that ideal relative glass thicknesses in this situation are 2/3 to 1/3 but this proportion is not available. I know that it is ideal to make up window and door myself to correct config. but I don't have skills to do this so am seeking best option available to me. I understand none of the choices are ideal but would really appreciate some advice on which of these options available would be best for door and window. I am prepared to sacrifice some therma insulation if I can get better acoustic properties. option 1-both panes acoustic glass of 8.8mm (air gap 12mm) option2-both panes acoustic glass with one being 8.8mm and other 6.4mm (air gap 16mm) option 3-one pane acoustic glass 8.8mm, other pane thermal glass 8.8mm (air gap 12mm) option4-one pane acoustic glass 8.8mm, other pane thermal glass 6.4mm (air gap 16mm) many thanks in advance jose

While editing is a grueling process, if you really work hard at it, in the end you may find that your piece has fewer words than it did before, which is great. Perhaps George Bernard Shaw said it best when upon sending a letter to a close friend, he wrote, “I’m sorry this letter is so long, I didn’t have time to make it shorter.” No quote better illustrates the point that writers are very busy. [SPAM SIGNATURE REMOVED. SPAMMER BANNED AND PERMANENTLY BLOCKED]

thanks thomasf2220 for your advice, much appreciated! any thoughts on my question?

thanks thomasf2220 for your advice, much appreciated! any thoughts on my question?

You won't be getting anything useful from him! He was just a stupid, lousy, idiot, scumbag, lowlife, parasitic worm of a spammer. Apart from that, he's probably a really nice guy! But we'll never know, as he has now been permanently banned and blocked from any future access to the forum. Sorry he managed to mess up your thread! But he's gone now... OK, so back to the actual subject:

I am having a wood framed practice/recording room built in garden ... I am at the point of configuring a double glazed external door and window.

Hang on a sec! That sounds like you are building only a single-leaf isolation structure! That won't get you much isolation at all, so using double-glazing is sort of a moot point. The total isolation of a building is only as good as the isolation at the "weakest" point. Since that will be the entire wall, it makes no sense to spend a lot of money on better isolation for just the window. In addition, double-glazing is not a good way to isolate for music in any case. It's good for isolating mid-range and high frequency sounds, but pretty lousy for low frequencies, such as drums, bass, low end of electric guitar, keyboards, etc. Here are the resonant frequencies for all of your options, and the estimated isolation: option 1- 1 x A 8.8mm, 1 x A 8.8mm (air gap 12mm) -- 165.1 Hz -- 35.5 dB option 2- 1 x A 8.8mm, 1 x A 6.4mm (air gap 16mm) -- 155.8 Hz -- 34.5 dB option 3- 1 x A 8.8mm, 1 x T 8.8mm (air gap 12mm) -- 165.1 Hz -- 35.2 dB option 4- 1 x A 8.8mm, 1 x T 6.4mm (air gap 16mm) -- 155.8 Hz -- 34.1 dB As you can see, there's not much in it either way, and the resonant frequency is very high in all cases. Bare in mind that the window does not isolate at all at that frequency: it only starts isolating at 1.414 times the resonant frequency, so around 230 Hz in all four cases. It only isolates well starting an octave higher, so around 330 Hz in all cases. That's way up in the mid range. So there's little to no low frequency isolation. On the other hand, if you were to do a proper two-leaf window in a two-leaf wall, with for example a single pane of 16mm laminated glass in each, with a 15cm air gap, you would get a resonant frequency of about 34 Hz, and total isolation of about 45 dB, and your isolation would start a full two octaves lower. (You would also have fantastic thermal insulation like that). You should probably re-think your isolation plan before proceeding any further, as a single-leaf structure is never going to get you good isolation. - Stuart -

Thanks Stuart for replying to both my posts regarding double glazed door/window and also regarding listening position orientation. thanks too for dealing with the spammer! since i posted the questions in October things have moved forward and decisions have been made and built on, in one way regarding build layers perhaps slightly better than originally proposed (use of resilient channels) and regarding door/window (already installed) not the ideal. here is how it is now. Structure (outside to in) shiplap cladding (decorative-I don't expect acoustic advantages) 18mm OSB 2"x4" timber studs 100mm RW3 resilient bars (new addition-not in my original plan) 2x15mm acoustic Plasterboard Door/window (doubel glazed-www.modernupvcwindows.co.uk) both panes acoustic glass with one being 8.8mm and other 6.4mm (air gap 16mm) Following your advice and others the orientation is now as you advice i.e. speakers firing from narrower to narrower side (I face 4m wall as opposed to facing 5m wall) Thanks too for your thoughts on height allowed. I did contact the planning office in my area and they told me that as I am less than 3m from boundary with neighbours no part of the building can exceed 2.5m but you are right that I could have built higher providing I were further from the fence. I know more height would have been better but on a purely domestic/family level it would have meant having the build taking up most of the available garded space leaving no room for my daughter to use. it is a compromise I decided to make. As it stands the RCs are in the process of being fitted to walls and ceiling. Door and window are already fitted. regarding the roof/ceiling the layers are as follows (top to bottom) 1.52mm EPDM 18mm OSB 2"x4" timber joists 25mm airgap (please see note below) 75mm RW30 Resilient channels there is also a support beam from one end to other narrow to narrow side (please see pic and note below) 2x15mm acoustic plasterboard The roof so far (no RW or RCs applied yet) concerned me a lot due to the 25mm ventilation gap but from the advice gathered on this and other forums it seems that this is essential and something I will have to live with, the main thing is to ensure the inner space (plasterboard layers) is very well cauled and completely sealed. The support beam was added as the builder admitted to having made a miscalculation and was concerned that the joists alone may not adequately support the roof. he came clean and I went with the beam rather than remove all joists and replace with thicker ones, this would have meant a loss of ceiling height for entire ceiling instead of just the height loss directly below the beam. I searched for advice on best way to deal with the beam and 2 options were given, either simply cover it with the 2x15mm PB or construct a hanging cage made from the PB suspended from parallel RCs (attached perpendicular to the joists) either side of beam. To be honest I would much prefer to just cover it with PB as this would obviously cost me less in labour and complexity, If this is a really bad decision then I will rethink it. I also think it would be a good place to be able to fix lights etc? If this is an option I am considering surface mounting all cabling to lights, would that be a good choice? I am on a very tight budget (like most of us I guess) and have decided (and bought) a passive acoustic vent (Rytons) which according to test data (obviously under ideal conditions) claim that when open it can reduce sound transmission by 43db and by 50db when closed. Again I know this is not ideal at all but I am prepared to pause making noise , open door and vent and allow some airflow. I do understand how inadequate this is compared to a proper HVAC system but feel that for the moment I will have to live with it as I cannot afford an HVAC at present. The electrics are due to be installed last. For this again I have read your advice and will go with surface mounting all cabling and sockets etc. There will be a separate service box with 3 circuits, Not sure if I need 3, thought just 2 would be required, one for anything related or connected to audio and the other fo rlights, heater, kettle etc. The electrician suggested 3 as a heater could be on a thermostat which could otherwise cause clicks and pops. I read your answer to another post which I found very helpful at this stage of the build, I was wondering how to attach the elecrical trunking to the walls. I understood that this should be screwed into the studs (with caulking etc) as opposed to the PB. I understood this to be best as plugs would be pulled and pushed into sockets and if attached only to PB it could eventually loosen or be pulled off the wall. Did I understand this correctly? On the same subject I am thinking along the same lines regarding attachment of the service box, should this also be fixed to the studs? As this would be heavy this seems right? Your advice is much appreciated, many thanks Jose

Hi Stuart and all, thanks for your reply to my earlier post. The electrics are due to be installed last. For this again I have read your advice and will go with surface mounting all cabling and sockets etc. There will be a separate service box with 3 circuits, Not sure if I need 3, thought just 2 would be required, one for anything related or connected to audio and the other for lights, heater, kettle etc. The electrician suggested 3 as a heater could be on a thermostat which could otherwise cause clicks and pops. I read your answer to another post which I found very helpful at this stage of the build, I was wondering how to attach the elecrical trunking and conduits to the walls. I understood that this should be screwed into the studs (with caulking etc) as opposed to the PB. I understood this to be best as plugs would be pulled and pushed into sockets and if attached only to PB it could eventually loosen or be pulled off the wall. Did I understand this correctly? On the same subject I am thinking along the same lines regarding attachment of the service panel, should this also be fixed to the studs? As this would be heavy this seems right? is this correct? Your advice is much appreciated, many thanks Jose Attachments:

Hello, thanks Stuart for your earlier replies. Right now I am a bit stuck on a decision about installation of surface mounted pvc trunking for mains power and sockets etc. I saw your response to someone elses post saying that rather than attach trunking to the PB it is correct to screw into the studs as plugs can be subject to a lot of pulling and pushing and PB could be damaged etc. I have struggled to understand this as i thought this would short circuit the effect of the RCs by screwing through the PB into the studs. Another related question is whether the service panel can also be fixed to studs. Have I misunderstood your advice or is this what I should do? will be speaking to electrician soon and hope to have clear instructions to give. many thanks Jose

I was wondering how to attach the elecrical trunking and conduits to the walls. I understood that this should be screwed into the studs (with caulking etc) as opposed to the PB. I understood this to be best as plugs would be pulled and pushed into sockets and if attached only to PB it could eventually loosen or be pulled off the wall.

Correct.

regarding attachment of the service panel, should this also be fixed to the studs? As this would be heavy this seems right? is this correct?

Right! Everything that will be attached to the wall must be attached through the drywall (PB), into the structure behind it. Drywall does not have much load carrying capacity at all. It's not meant to be a structural member. Anything that you attach to the walls must be screwed through the drywall into the structure, not just into the drywall.

I have struggled to understand this as i thought this would short circuit the effect of the RCs by screwing through the PB into the studs. Another related question is whether the service panel can also be fixed to studs.

If you are using resilient channel (RC), then you would screw through the drywall into the RC, NOT into the studs. You only screw into the studs if your wall is built without RC, as a stand-alone leaf. In the place where you saw me telling someone else to attach his electrics to the studs, they probably had built a fully decoupled wall that does not use RC. Will be using RC in your walls, or will you be building proper fully-decoupled walls?

There will be a separate service box with 3 circuits, Not sure if I need 3, thought just 2 would be required, one for anything related or connected to audio and the other for lights, heater, kettle etc. The electrician suggested 3 as a heater could be on a thermostat which could otherwise cause clicks and pops.

Right! Listen to your electrician. He has the right idea. I normally have one circuit just for lights, one fore all the audio equipment, and at least one for "service" loads, such as HVAC, kettle, vacuum cleaners, charging cell phones, floor lamps, etc. Any load that does not have a signal going to the sound system, goes on the "service" circuit. If there's a heavy piece of equipment, such as the HVAC system, then I usually put that on it's own separate circuit. - Stuart -

thak you Stuart for your clarification, it's a huge help! You are right it will just be a single leaf structure, layers as follows shiplap cladding (decorative-I don't expect acoustic advantages) 18mm OSB 2"x4" timber studs 100mm RW3 resilient bars (new addition-not in my original plan) 2x15mm acoustic Plasterboard When I first spoke to the electrician I asked whether the trunking and service panel can be fixed (through the 2 PB layers) into the RCs and he said no, they needs to be screwed into the studs, I am guessing this is the standard way of doing it in a domestic structure which is probably how he has always done it!. Am I right to think if the RCs can support 2x15mm PB then they will hold the PVC trunking and service panel with no undue strain? Just for me to get it 100% right when I speak to him again here is what I will instruct him to do,(please kindly flag up any errors). sorry to restate it but it is to ensure I get it right and can back it up with your advice. Service panel to be screwed through the 2 layers of PB then into the RCs being careful to avoid studs trunking to be screwed through the 2 layers of PB then into the RCs being careful to avoid studs Another question:- I have understood that service (heater, kettle, lights etc) and audio related power cables (eg to speakers, audio interface) can run parallel to eachother (?) but be spaced at least 2m (?) from eachother. does that mean the power leads feeding these different types of devices cannot be layed in the same length of trunking but need to be fed along different trunking runs keeping them a safe distance apart? Guess it can be done but would be extra cost for the trunking and would not look so neat. Or did I misunderstand the advice I found, is it simply that the electrical power leads should not run parallel to audio leads (mic, speaker leads etc)? Your advice has been invaluable Stuart, many thanks Jose

You are right it will just be a single leaf structure, layers as follows shiplap cladding (decorative-I don't expect acoustic advantages) 18mm OSB 2"x4" timber studs 100mm RW3 resilient bars (new addition-not in my original plan) 2x15mm acoustic Plasterboard

Actually, that is two-leaf, not single leaf! :) The resilient bar (resilient channel, RC) decouples the plasterboard from the studs, so that is a two-leaf system... There's only one frame here, yes, but still two leaves. RC is the secret. But do make sure it really is RC! Or alternatively, you can use normal hat channel along with RSIC clips. But not both. Ie, you have two choices: 1) Resilient channel by itself. 2) Hat channel on isolation clips. Those are correct. It would be INCORRECT to use only hat channel, and it would be INCORRECT to put resilient channel on isolation clips.

When I first spoke to the electrician I asked whether the trunking and service panel can be fixed (through the 2 PB layers) into the RCs and he said no, they needs to be screwed into the studs,

Why? I don't see the reason for that. RC is designed to handle the weight of drywall, just like studs, so there's no reason why it would not be able to handle the weight of a distribution panel.

I am guessing this is the standard way of doing it in a domestic structure which is probably how he has always done it!.

Yup! Probably. In other words, he didn't know, so he played it safe and told you the wrong thing. Go talk to your inspector, to find out for sure. But first talk to the manufacturer of your RC to find out what they recommend.

Am I right to think if the RCs can support 2x15mm PB then they will hold the PVC trunking and service panel with no undue strain?

As far as I'm concerned, yes! Two layers of drywall weighs about 25 kg per square meter, and RC is usually able to handle three layers with no problem.

Service panel to be screwed through the 2 layers of PB then into the RCs being careful to avoid studs trunking to be screwed through the 2 layers of PB then into the RCs being careful to avoid studs

Right! That's what I would do, but do check your local code, and do talk to your inspector.

I have understood that service (heater, kettle, lights etc) and audio related power cables (eg to speakers, audio interface) can run parallel to eachother (?) but be spaced at least 2m (?) from eachother.

Nope! All power cables can run right next to each other. No need to separate them. It's the signal cables that should be kept far away form the power cables.

Or did I misunderstand the advice I found, is it simply that the electrical power leads should not run parallel to audio leads (mic, speaker leads etc)?

Right! - Stuart -

Thank you very much Stuart for your response. Your confirmation that I am on the right track regarding the questions I had is very reassuring. Just to confirm I have had installed proper Resilient channels and not attempted to combine these with hat channels. Your clarifcation on screwing the electrical trunking (through plasterboard) into the RCs is also very helpful and makes perfect sense to me. so far all the RCs have gone up and 2 layers of PB have been fixed. I have ensured that all studs were marked on the PB prior to fixing to the RCs to avoid screwing into the studs. so far the ceiling RCs have gone up and the pB will be fixed next week. Do I need to also fix ceiling lights to the RCs or, with the correct fixings can they be fixed to the PB only and therefore put up wherever I need them? A couple of oversights I am guilty of and hope are not grave mistakes:- 1) As outlined in earler posts I have a central longditudinal beam supporting joists (please see pic), the builder fixed the Rcs on the ceiling but the spacing of them was not equidistant to the beam (my error in not supervising!) meaning that if fixing light to RCs only is necessary then the lights would not be symetrically arranged relative to the beam If fixing lights to the PB alone is not an option the builder has suggested he can fit RCs wherever I want the lights to be. Is this an acceptable option? 2) On one wall ( where service panel will go) the builder did not fix an RC just above floor level but higher up (bit less than 1 foot), not sure why he did this but again my oversight. As all 4 walls now have 2 layers of PB fixed this means that the trunking will need to be fixed at that height if it is to be fixed to the RCs. For me this is not aesthetically ideal but, looking for the possible advantages in a less than ideal scenario, my thought is that it might mean that there is less `kick risk`having trunking (incorporating sockets) some distance above floor level all round. Is this a problem functionally? If just aesthetic then I guess I can live with it but to me it spoils the look a bit!. I am a bit unsure of how many lights I might need on the ceiling. I can discuss this with the electrician but my initial thought is to have 2 spotlights either side of the central beam (4 in total at this position) above my main desk avoiding a ceiling cloud which I intend to have installed. I am planning a sofa at the back of the room and thought to have another 2 spots either side of the central beam (4 in total at this position) in that area and again not in positions where ceiling panels may go. I am not intending to use LED bulbs as I have been learning how harmful this kind of `blue` light can be for the eyes long term. I know the electricity consumption and heat emission would be higher using other bulbs but will probably go with halogen or incandescent bulbs. Providing the bulbs are interchangeable I can always decide to switch to LED later if I choose. I am not having any dimmers on the lights. Any thoughts would be much appreciated. Many thanks again Stuart Jose

hello again, following on from my earleir posts I have an issue which I admit i know very little about but understand the crucial importance of getting right. I will shortly be having the electrics installed in my music room. as outlined earlier There will be a service box with 3 circuits thus separating audio, service (lights etc) and heaters on separate circuit. during an initial conversation with the electrician I flagged up the need for Star Grounding as I had read on this and other forums how essential this is to avoid audio hums and pops etc. he said he could guess that the forums were USA based but that it is not common practice here in the UK. At that stage and because I understand very little of the procedures and terms I left it at that (intending to further inform myself). I had a more recent conversation with the builder about this issue and he said that the reason the electrician was not considering star grounding is because the practice does not comply with UK regulations and would be illegal. I am ignorant of the regs in the UK and don't know the terminolgy, does anyone know more on this specific to the UK? If star grounding goes by another name here it would be great if someone could tell me what it is so at least I have the right terminology! Is simply having the audio related devices on their own circuit enough to avoid unwanted hums etc or should I insist on star grounding every socket? What I want to avoid is just going along with what the electrician normally would do in a non-studio set up to save himself the extra work needed to do it right for my application. If he can't or won't do it right then it is not too late at this stage to get someone who can. Any advice would be much appreciated. many thanks Jose

the electrician was not considering star grounding is because the practice does not comply with UK regulations and would be illegal.

:?: :shock: Huh? I'd REALLY like to see the relevant part of your electrical code that makes it illegal to ground all electrical outlets to one central ground!!!! I have a feeling that these guys don't actually understand what star grounding is, don't want to admit it, and in order to not look foolish they are trying to just not do it! Ask them for the specific section and paragraph of the UK electrical code that forbids grounding all electrical outlets to one central point. As far as I know, "ring circuits" are commonly used in the UK, but that does NOT make radial circuits illegal. Ring circuits are done to save money, and to make things easier on the electrician. Radial circuits are safer, and far less noisy, electrically. (It is virtually impossible to have an unbalanced flow in the live and neutral conductors with radial circuits: it is both possible and probable in rings circuits). I'd be REALLY surprised if there is anything in the UK electrical code the makes radial circuits illegal. Star grounding is basically radial wiring, instead of ring wiring, and it is very simple: All that you do is to run three conductrs from each plug, back to the distribution panel: the "live" conductor, the "neutral" conductor, and the "earth" or "ground" conductor. Inside the distribution panel, you connect all of the "ground" conductors to a "ground" bussbar, all of the neutral conductors to the "neutral" bussbar, and each of the "live" conductors to its own circuit breaker. That's it. I see no reason at all why this would be "illegal" in the UK, so if someone claims that it is, then they would need to convince me be showing the chapter and verse that specifically makes it illegal. I'm not aware of any other country in the world where it would be illegal, and I've lived in a few of them myself! EDITED TO ADD: I just googled it, and according to Wikipedia, (take that as you will): "The ring circuit is still the most common mains wiring configuration in the UK, although the 20 A radial is also permitted by the Wiring Regulations." - Stuart -

Hi Stuart, Can't tell you how much I sincerely appreciate your prompt response particularly as this stage into the build is so imminent. What I will do is have another conversation with the electrician and insist on what I require or otherwise find an alternative contractor. Just for my clarity, do all 3 circuits need to be star grounded or just the 'audio' circuit? Are there additional strategies I need to demand such as surge protection that I will need to ensure a quiet and clean power supply? I also need to know whether the ceiling lights can be fixed to the PB or do they need to be fixed to the Rcs, if they can go directly onto the PB that would give me more choices on where to locate them without having to have extra RCs fitted where I want them if there are none already in that position (please see previous post with pics). Stuart I genuinely appreciate your invaluable advice given throughout this process, I am learning so much! José

Hello again, further to an earlier post of mine regarding how to fix electrical PVC trunking to PB. Stuart you advised:- (my question) When I first spoke to the electrician I asked whether the trunking and service panel can be fixed (through the 2 PB layers) into the RCs and he said no, they needs to be screwed into the studs, (your reply) Why? I don't see the reason for that. RC is designed to handle the weight of drywall, just like studs, so there's no reason why it would not be able to handle the weight of a distribution panel. The electrician has now delivered trunking, I instructed him to do as you advised but one issue that is apparent is that the trunking casing which is to be fixed to the wall is wider than the RC that lies under the 2 layers of PB meaning both screws cannot be fixed to the RCs. Electrician says that the upper screw can go though the PB into the RC and the lower screw will have to go into the PB as both screws are needed to secure the trunking casing adequately. Please see attached drawing and pic. I have 3 related questions. 1) If it is to be done as I outlined what is the right way to fix the trunking's lower screw to the PB as it will be below the RC?. 2) Is there a special type of rawl plug (uk name) or similar that should be used? 3) If there is a suitable way to screw trunking directly to PB does that means I can disregard the location of the RC (best available RC is at approx 400mm from floor i.e.higher than I prefer trunking to be) and fix trunking (using correct screw plugs) with both screws going into PB only without fixing to RCs at all? any advice would be much valued. thank you. Jose

Hello all, sorry been under the radar for a while. Found myself a bit caught off guard as a consequence of my own inadequate planning, have been having to make some crucial decisions very quicky and have been kicking myself for not having given adequate thought to some issues. I am sharing some of my oversights (despite feeling embarrased!) in order for others to not make the same mistakes and also to seek further advice if possible. In the last few days the surface mounted electrical trunking has been fixed to the walls (please see pics). For the electrician to then proceed I had to give him precise locations of all the sockets I want and define whether they are to be for audio related devices, service (kettle , printer, fan etc) or heaters. decided on 12 audio sockets and 10 service, overkill? Although I had a pretty clear idea of where each piece of gear would go (similar to my current setup) I was a bit caught out by exact location and number of sockets. this I think was partly because in the past I have never had a choice and always had to just work with what I had! I literally had to enact my recording procedure in my head to try and ensure I could comfortably reach the desk whether standing to record my vocals or seated to record guitar. This would be different if I were left handed but had to really think it through. Another issue which I spent hours measuring and sketching to get a clear solution is where exactly to put ceiling lights. I am initially planning on having 2xGIK 244 absorbers as a ceiling cloud but until I have some gear set up in the room I can't accurately determine where the speakers would be and therefore where the reflection points on the ceiling will be and consequently where to put the lights to not interfere with the ceiling panel placement. I rang GIK (UK) and got some good advice to allow space to add ceiling panels if needed in the future. This then led me to think very carefully about where and what orientation I want the lights so as to leave space for possible future panels. I then made sure i have ordered lights with a 350 degree tilt/rotation so I can throw light onto my desk from their position which would not be right over my head. lights go up day after tomorrow. One question maybe someone could offer advice on although I am sure it has been answered a thousand times before is how to deal with the cable penetration as it is right now. Builder fed cable from outside via a trench , into cavity (filled with 100mm RW) between outer OSB and inner layers of PB, it then came out through PB wall on inside (ps cable visible in pics fixed to adjacent fence is unrelated leftover from a demolished shed). The builder initially caulked inner penetration but later (to my dismay) the electrician pulled and pushed to loosen it and dislodged all the caulking! I had an in-depth conversation with him about the importance of sealing it again very thoroughly. He assured me he will do this but I am unsure how to direct him. I asked if he could put the penetrating section through a piece of conduit then stuff with rockwool then caulk at surface, the caulking was no problem but he said he can't now put the cable through conduit. Not sure if this is right but have read similar guidance on this and other forums. Short of ripping it all out and starting the penetration process afresh is there something I can advise him to ensure the best seal? Where the cable emerges is approx where the service box will be, I had a thought that if the sealing is inadequate that I could have an isolating box built around the service box (think I read in Rod Gervais's book) The other issue which has been doing my head in (as we say in uk!) is the realisation that the plan I had to use a Powerline network for internet access may or may not work due to the fact that the studio will have a separate service panel with it's own RCD. Sorry if this is for a different forum topic but still may serve to help someone else plan better than I have!. I know I could bring a phone line from the house 20m away then relocate the router to the studio or bring a Cat5 cable but I understand the cat 5 should not run close to power cabling due to interference. either of these 2nd options could require a 2nd penetration which to me sounds like a disaster!! electrician suggests if needed it could come in via hole drilled under the door!! I may have to resort to my least prefered option which to most may sound the most obvious which is a wifi signal boosted from the house. reason I don't want it is the health risks for anyone within 15' of a wifi router i.e. my family members. some may think I am a crank but the info is out there and credible. so to end my rambling post main questions relate to sealing cable penetration how to bring in a CAT5 or phone line if Powerline network doesnt work (won't know until electrics up and running) Any guidance much appreciated thank you Jose