Zoothorn's Build Plan

[zoothorn]

4 minutes ago, the_r_sole said:

 

exactly, so why are you asking for the information to give to your builder?!!?

Either it's the builders remit or it's not, just leave it up to the builder to make sure it's compliant with the regulations, don't specify anything yourself because you are not placed to do that

 

Because it'll look a bit sh*te if I just give 4 thin lines for my walls, that's all! You see its nothing to do with me getting the -construction details correct- its is instead everything & only to do with me getting the -critical placements correct- . Its what he himself said/ wants.

 

I just want my plan at the least to look as good as it can be, so A) so he has as much confidence in my critical dims/ placements as I can muster (so he doesn't worry I'll come back on day 5 "ooh can we shift door X along a bit?"), B) it looks like I've made the effort, C) it just looks better esp if he has to hand as a 'guide to build from' daily, D) it makes me feel like I've done my part best I can.

[the_r_sole]

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Edited September 26, 2019 by the_r_sole

[zoothorn]

1 minute ago, the_r_sole said:

 

With all due respect, you don't know enough about it - your builder apparently does. 

He should be the one advising you on what the achievable dimensions are by working it out from the planning drawings and his knowledge of building regs compliant constructions, anything else is pointless.

Why not just overmark written dimensions on your planning drawings?

 

Yes. Will do. But look all I'm trying to do, is give him a decent impression of what the wall construction is.. not precisely.. surely you could just help me out by saying "just put 100mm (block clad) + 50mm cavity + 150mm for inner TF wall" (I'm just throwing 50mm + 150mm figures in the wind here: they might not be so far off/ might be ok to go with).

 

A certain degree of vagueness is -FINE- for this exercise.. but I'd prefer to be nr'ish on the money tho being a bit of a perfectionist myself.

 

Maybe that clarifies the point of my thread here; do you get now a bit more of what I'm getting at?

[andyscotland]

10 minutes ago, zoothorn said:

I do not need professional support. I just need someone to tell me a common timber frame inner course thickness, & I can pass the buck on to my builder whom I trust. That is what he has asked me to do: and is expecting -nothing- more complicated at all than that from me.

Ok, one last attempt.

 

Common timber frame thicknesses are 90, 100, 125, 140 and 150mm.

 

Some of those, on their own, will not fit enough insulation to meet the u value requirements. Depending of course on the type of block and the type of insulation. They may therefore need an extra layer of rigid insulation between the timber and the plasterboard, or outside the blocks.

 

Some of those are only strong enough to carry their own weight, others will be able to carry the roof, others will be able to withstand wind loading.

 

Some will need a rigid sheathing board, commonly 18mm but varies (and sometimes not required).

 

Off-site prefabricated panels have a different range of sizes again.

 

It's simply not possible for us to tell you what thickness the wall will be.

 

Nor is it possible for you to tell the builder the thickness and then "HE builds the walls to satisfy BCO: HE decides the membrane & C'tex "U factor" etc etc.."

 

The wall thickness depends on those decisions. So if the builder is making them, only he can tell you how thick the wall will be.

 

Your planning drawings should already show the outline sizes, door size and position etc - all the info the builder needs for you to "pass the buck to him". Hence why we're struggling to understand what additional detail you're now trying to draw and why, if he's doing the construction design, he needs it.

[the_r_sole]

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Edited September 26, 2019 by the_r_sole

[zoothorn]

I give up. You're just not understanding from where I am here.

 

If anyone can give me a typically-used TF inner course thickness figure (for a simple TF house extention).. plus if there needs to be a cavity, what a typical cavity dim might be- I'd be grateful. Afaik the cladding material doesn't alter what thickness the innitial/ structural TF course would be.. so very likely a typically-used inner wall thickness for many builds including extentions (& from amongst the ton of info I've read I think this is indeed the case- its just finding it again that's all).

 

If not I'll just go with 100mm + 50mm + 150mm.. but this is a bit of a stab in the dark.

 

Thanks, zoot.

[the_r_sole]

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Edited September 26, 2019 by the_r_sole

[zoothorn]

1 minute ago, the_r_sole said:

 

What you are not understanding is, it simply doesn't exist because it depends on various other factors.

 

Mr. Sole we're going round in circles here. I don't need it to be critically correct (but you keep stipulating that's what is needed- why Ive no idea) so I don't need to entertain these various other factors- these are only for my builder to. Its some of what I will be paying him for.

 

Look for eg: I put 100mm (block clad) + 50mm cavity + 150mm (inner TF) on my plan. He sees it. If he knows this isn't either A) correct to BRegs or B) precisely what he was going with he will NOT just blindly follow my dims & build to my dims: he'll just override & build the damn thing to 100mm + 25mm + 200mm, or whatever it is he was going to do, which he knows will be up to BRegs std.

 

In the above two eg's it makes absolutely -no- difference to the outer corner point. That remains fixed. The only thing that changes is I have fractionally less space inside my room than my plan. Its of no consequence; in other words my 150mm (+50mm) figure is of no real critical importance.. in fact its n/a to a certain degree, because I'm not the builder/ the one whose agreed (with me) to build the walls to BRegs std.

 

Now do you understand where I'm coming from? its my last try to explain.

 

1) B

[the_r_sole]

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Edited September 26, 2019 by the_r_sole

[jack]

17 minutes ago, zoothorn said:

I give up. You're just not understanding from where I am here.

 

6 minutes ago, zoothorn said:

Mr. Sole we're going round in circles here.

 

Why are you asking people on the internet to answer an unanswerable question, over and over again? You're getting the same result expressed several different ways from different people - that's a strong hint that you're the one not understanding the situation, not them.

 

Why not just ask your builder exactly the same questions? If he's as experienced and competent as you say, he'll give you the answer you need with a 30 second phone call.

[Onoff]

A quick Google for "u value for different timber frame" then Images:

 

https://www.google.com/search?q=u+value+for+different+timber+frame&safe=active&client=ms-android-samsung-ga-rev1&prmd=inv&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjon-7clajkAhVWRhUIHQ8nAgIQ_AUoAXoECBAQAQ&cshid=1567085463025&biw=360&bih=612

 

See the many details at the timber-frame-suppliers.co.uk links.

 

Many ways to skin this cat.

[andyscotland]

11 minutes ago, zoothorn said:

In the above two eg's it makes absolutely -no- difference to the outer corner point. That remains fixed. The only thing that changes is I have fractionally less space inside my room than my plan. Its of no consequence; in other words my 150mm (+50mm) figure is of no real critical importance.. in fact its n/a to a certain degree, because I'm not the builder/ the one whose agreed (with me) to build the walls to BRegs std.

 

OK - am now clearer that you're not actually trying to specify any of these things.

 

In that case, my very strong advice would be to tell the builder that he has the planning drawings (which presumably show e.g. the fixed outer corner point and the position of the door), that those are the only drawings that exist, and that your understanding is he will entirely take responsibility for getting from that to a completed building.

 

The problem with providing neat drawings that contain information that is "of no consequence" is that sooner or later someone along the way misunderstands the status of the drawing. And orders materials / sets out a corner / etc based on a detail or dimension that looked like it was of critical importance even though in your head it isn't. If you are not experienced in producing construction drawings, there's a fair chance you will draw or label something that you think is just diagrammatic without realising the implications of where you just put your pencil. And that will make it your problem, and your cost, to solve.

 

In my experience, it's much better if drawings don't exist (or at most look like a fag packet sketch) than if they exist but are not accurate. Drawings that don't exist prompt people to ask questions and discuss answers.

 

If you're determined to produce a build plan, draw the accurate lines (from your planning drawing) neatly with a scale ruler. Then draw the internal walls freehand, roughly 300mm away for an external wall, 150mm for internal, and roughly shade the gap so it looks more like an estate agent's floorplan than the architect drawings he's given you as an example. Do not attempt to draw the different material layers etc. Calculate and mark all your dimensions by reference to the external walls. This will encourage anyone looking at the plans to realise that they're looking at a sketch, not a drawing. Alternatively, you could print off the planning drawings and mark up - freehand - rather than trying to redraw them.

[zoothorn]

3 hours ago, jack said:

 

 

Why are you asking people on the internet to answer an unanswerable question, over and over again? You're getting the same result expressed several different ways from different people - that's a strong hint that you're the one not understanding the situation, not them.

 

Why not just ask your builder exactly the same questions? If he's as experienced and competent as you say, he'll give you the answer you need with a 30 second phone call.

 

Perfectly reasonable post Jack. Because I'm getting stressed at folks not understanding, that's all.. & yes I should have thought of just asking my builder instead but thought this the best place for the simple of a basic TF wall + block cladding Q to be answered: I thought it likely a std dim from build to build (& know actually that in fact it is, but for some reason I'm just not being told & left to flounder, prob bc they can see I'm stressed & find some strange comfort in watching me get more stressed).

 

Oddly enough I just ran into my builder in Jewsons.. so thought why not ask him (& why didn't I think of doing so?) > "I'm just doing your plan Dai: wall thickness, 100mm block +? +?".. "50mm cavity & 150mm  innerTimber Frame course" he said. This is -not- something we've discussed before, so, therefore 99% likely industry standard TF+block cladding figures I found in my book coinciding with info online etc (& on here probably too). The thing I find incredulous is that someone didn't at the least say 'yes/ possibly 100mm/50/150mm' but instead just chose to argue & pick at my erfforts/ pick at me instead. I don't need this at all.

[andyscotland]

2 minutes ago, zoothorn said:

 the simple of a basic TF wall + block cladding Q to be answered: I thought it likely a std dim from build to build (& know actually that in fact it is, but for some reason I'm just not being told & left to flounder, prob bc they can see I'm stressed & find some strange comfort in watching me get more stressed).

 

No, because we genuinely, hand-on-heart want to help you avoid problems. Based on problems that we have seen happen to other people (or that have happened to us).

 

And because, as we've repeatedly tried to explain (and I spent quite some time trying to give examples to help you see the complexity of what you were asking when you wouldn't just take our word for it) it's not a standard dimension from build to build.

 

Yes, some sizes are more common than others. And yes, your builder probably does know off the top of his head which of the common sizes he'll build. He knows your project, he knows your site, he probably has a fair idea of your existing house (which affects u-value targets for the extension) etc, etc.

 

We don't.

 

By way of example, I am converting my garage and building a 2 metre by 2 metre utility on the front. It is a ludicrously simple project, really - a 30 square metre L-shaped building with two rooms.

 

My walls are 183mm, 244mm, 262.5mm, 275.5mm and 270.5mm. There are very good reasons why each of them is different. And why I have 5 thicknesses of wall when on a simple outline drawing my room only has 4 walls : one changes thickness part way along.

 

So you see, it's not even a standard dimension from wall to wall on a single build with a single designer, never mind from build to build.

 

I'm glad that you were able to speak to your builder and that he was able to answer your questions. Hope that has reduced your stress.

[zoothorn]

3 hours ago, andyscotland said:

 

OK - am now clearer that you're not actually trying to specify any of these things.

 

In that case, my very strong advice would be to tell the builder that he has the planning drawings (which presumably show e.g. the fixed outer corner point and the position of the door), that those are the only drawings that exist, and that your understanding is he will entirely take responsibility for getting from that to a completed building.

 

The problem with providing neat drawings that contain information that is "of no consequence" is that sooner or later someone along the way misunderstands the status of the drawing. And orders materials / sets out a corner / etc based on a detail or dimension that looked like it was of critical importance even though in your head it isn't. If you are not experienced in producing construction drawings, there's a fair chance you will draw or label something that you think is just diagrammatic without realising the implications of where you just put your pencil. And that will make it your problem, and your cost, to solve.

 

In my experience, it's much better if drawings don't exist (or at most look like a fag packet sketch) than if they exist but are not accurate. Drawings that don't exist prompt people to ask questions and discuss answers.

 

If you're determined to produce a build plan, draw the accurate lines (from your planning drawing) neatly with a scale ruler. Then draw the internal walls freehand, roughly 300mm away for an external wall, 150mm for internal, and roughly shade the gap so it looks more like an estate agent's floorplan than the architect drawings he's given you as an example. Do not attempt to draw the different material layers etc. Calculate and mark all your dimensions by reference to the external walls. This will encourage anyone looking at the plans to realise that they're looking at a sketch, not a drawing. Alternatively, you could print off the planning drawings and mark up - freehand - rather than trying to redraw them.

 

I'm not quite understanding "it's much better if drawings don't exist".. but appreciate the advice. Actually I'm not quite understanding the very rough sketch idea you're outlining here either.. but appreciate the help. I've been told though by builder to do plans, just the very basics, based on the detailed Full Plans [photos #1 provided to me just as a guide] rather than any rough sketch tho. I'm only following orders.

 

I'm not looking to replicate Full Plans, in freehand. No that's not what I've been told to do. But nor is a rough sketch looking 'very freehand'. Its just between the two I'm aiming at. Ive just been in library trying to do a basic box + door (my lower room) with 3 or so free online software things & could get barely anywhere but a big frustating pickle after 2 hrs trying abc xy&z. No fkn way. Its a waste of time.

[zoothorn]

Ok @andyscotland I do see more of what you are trying to do to help- thanks alot. Its innevitable though that from your pov, not knowing me at all, or my builder, that the advice would be waaaaay on the safe side, just to cover your opinions as it were. Its at tricky area of giving advice, from one to another, having no direct face to face communication (actually its the very achilles heel of all forums IMO.. but there's a rabbit hole I aint moseying down for now!).

 

I must disagree though that 100mm block /50mm cavity/ 150mm inner course, for a TF build.. aren't industry std figures. From what I read, these figures cropped up enough times for me to have quoted them 'from the blue' to know they had weight/ relevance = they are often used.

[Onoff]

30 minutes ago, andyscotland said:

My walls are 183mm, 244mm, 262.5mm, 275.5mm and 270.5mm.

 

Sounds like my house!

[Cpd]

FFS  @andyscotland and @the_r_sole I applaud your efforts, I must remember to ask you both about how long I should cut this piece of string I found on the beach........ got to love an enlightening post about the specifics of an unknown specification....... carry on ! 

[dpmiller]

1 hour ago, zoothorn said:

 

I must disagree though that 100mm block /50mm cavity/ 150mm inner course, for a TF build.. aren't industry std figures. From what I read, these figures cropped up enough times for me to have quoted them 'from the blue' to know they had weight/ relevance = they are often used.

 

Weird. my 2-storey, 270sqm build only uses 140mm frames. will my house fall down?

[andyscotland]

@zoothorn it may seem pendantic, but there is a very important difference between "common" and "standard".

 

Yes, 100/50/140-150 is common. It is often the most cost effective way to balance the various constraints in the most common conditions.

 

But that does not make it standard. Standard implies it will always be valid, and there are many, many situations in which it is not.

 

This is where it gets particularly dangerous. If you do a neat careful drawing of a common construction detail, it is very easy for the builder to assume someone has checked it is valid for your situation. And because it is common, they won't question it. Which then leaves you high and dry if in fact you needed something less common to suit the constraints on your build.

 

In my experience, in problems often boil down to one of two causes:

 

* A client who was vague when they should have been specific. e.g. "make it roughly 4 feet wide". Builder uses a full sheet as that's easiest for him and the client doesn't seem to mind. Later turns out it needed to be exactly 1.1 metres, and it's too big. But the builder made what he was asked to make.

 

* A client who was specific when they should have been vague. E.g. "make it 140mm thick". The number is plausible, and builder assumes the client has done the calculations to get the specific value. Later turns out the client meant "make it have a u-value of 0.18", and there's not enough insulation depth. But the builder made what he was asked to make.

 

I have seen this happen again and again, not just in construction-related fields but also in software development (my current trade) and elsewhere.

 

Or, think of it another way. Imagine for a moment you do hire an architectural technician to do your building plans. Would you prepare them a drawing showing what you wanted?

 

No, of course not. You'd give them the planning drawings and tell them to draw up construction details and come back to you with any questions.

 

When you pay a technician to draw construction drawings, you're not really paying them to draw - anyone can do that. You're paying them to do the calculations and make the decisions required to know what should be built. The drawing is just the way they communicate those calculations to the builder.

 

In your situation, you are not paying someone for drawings. But you are paying the builder to do the calculations and make the decisions that a technician would have done. The builder may do some drawings (e.g. for a panel supplier) or he may do it all in his head. Regardless of how he chooses to communicate with his team, he has taken on the role of the technician.

 

If in the midst of that there are drawings floating around that you've done based on what you think is "standard" there will be conflicting information. And conflicting information always, always means trouble.

 

The more carefully you draw, the more it looks like you've put a lot of thought (and knowledge) into what you're drawing. And the less likely it is that someone will query it. People don't like to think unless they have to.

 

If there is no drawing at all, the builder will have no option but to think about everything. If there is a rough sketch, it will still be obvious nobody is meant to actually work from it.

 

You need to insist the builder does all the thinking you're paying him to do. This is the only way to ensure you and he are on exactly the same page about who is responsible for what. If his role is as you've described it to us, he should be able and happy to work from the planning drawings.

[jack]

10 hours ago, andyscotland said:

@zoothorn it may seem pendantic, but there is a very important difference between "common" and "standard".

 

Great post Andy.

[zoothorn]

@andyscotland hi, if I can just pick up on this (still waiting on balcony decision y/n, affecting overall build extent by a bit.. so yet to do my plan).

 

You seem to be referring in your info/ post above (all appreciated btw & read 2x) to my doing "Full Plans" from which a builder directly builds from, like an architect usually provides. But I am not doing this/ I do not need to do this.

 

I am going the 'Build Notice' route (more costly, more BCO checks, but £saving on the cost of 'Full Plans' route: bc build is so simple/ small/ builder capable/ BCO & builder know each other/ BCO happy my going this route). And in order to do this, my builder has asked me simply for 'critical dims', on a very basic plan, to scale.

 

So the precise 'u-value' info, etc etc etc is not needed for this plan. I just need to get the wall thickness right, triple-check my door placements, windows, ceiling H.. & I can crack on. I was just wondering if there's some way to do this plan, other than to hand-draw it.

 

Thanks, zoot.

[andyscotland]

@zoothorn I feel a sense of déja-vu coming over me...

3 hours ago, zoothorn said:

@andyscotland

So the precise 'u-value' info, etc etc etc is not needed for this plan. I just need to get the wall thickness right

 

The wall thickness depends on the u-value, and the u-value on the wall thickness.

 

So even though you don't need to show the u-value or provide it to the council in advance, you most certainly do need the precise u-value info in order to get the wall thickness right.

 

You cannot tell the builder what the wall thickness should be, he needs to tell you what it is (after he has done his u-value calculations).

 

You therefore also cannot tell the builder any of the critical dimensions that depend on the wall thickness.

 

In terms of actually drawing it, there are many many ways including various free or cheap drawing and CAD software packages (the latter being able to draw to scale and calculate / mark dimensions from the drawing).

 

However I think it will take you a fair while to find one, install it and learn how to use it. And if you use it incorrectly you will introduce (costly) errors into your plans.

 

My advice is still therefore the same as it was - draw it by hand and take extreme care that you are not accidentally specifying something that the builder should be deciding for you.

[zoothorn]

On 05/09/2019 at 13:45, andyscotland said:

@zoothorn I feel a sense of déja-vu coming over me...

 

The wall thickness depends on the u-value, and the u-value on the wall thickness.

 

So even though you don't need to show the u-value or provide it to the council in advance, you most certainly do need the precise u-value info in order to get the wall thickness right.

 

You cannot tell the builder what the wall thickness should be, he needs to tell you what it is (after he has done his u-value calculations).

 

 

Yes deja-vu me too! As I've explained time & again why u-value is irrelevant to just draw 100mm block/ 50mm cavity/ 150mm TF on a plan.

 

So what aren't you understanding here? I did not need precise u-value info to get the wall thickness as you say I do.. I just asked the builder "what wall thickness do you want me to put on the plan?" Was I asked to put this info on my plan? No. Was there any need to hijack my thread with such info when Ive explained clearly its n/a for what I've have been asked to do, by my builder? No.

 

It is a Build Plan, & a simplified one, as asked by my builder, as I explained in #1. It is --not-- Full Plans as would be done by an architect with alot of detail such as u-value. So u-value is --not-- relevant, to me, for this job . Why on earth is this not being understood?

 

[andyscotland]

1 hour ago, zoothorn said:

I just asked the builder "what wall thickness do you want me to put on the plan?" 

 

That wasn't at all clear in your post. You said that your builder had asked you to draw a plan with "critical dimensions" and later that you "just need to get the wall thickness right". That implied you were still at the stage of you telling the builder the thickness, rather than him telling you.

 

1 hour ago, zoothorn said:

Was there any need to hijack my thread with such info when Ive explained clearly its n/a for what I've have been asked to do, by my builder? No.

 

I find that pretty aggressive to be honest. You specifically tagged me and asked me to answer a question that I have answered (at quite considerable gift of my time) several times already in this thread. Based entirely on a desire to help you avoid problems. Not sure how that counts as having "hijacked your thread".

 

2 hours ago, zoothorn said:

It is a Build Plan, & a simplified one, as asked by my builder, as I explained in #1. It is --not-- Full Plans as would be done by an architect with alot of detail such as u-value. So u-value is --not-- relevant, to me, for this job . Why on earth is this not being understood?

 

I could equally ask "why on earth is this not being understood" that I am totally clear that you are not trying to do a full plans submission. It would be clearly ludicrous for anyone to suggest a sketch with a mix of ruler lines and freehand lines and the bare minimum info on a document you were going to send to the council for pre-approval.

 

The point stands that whether you are going Full Plans or Build Notice, the council will at the end check that the completed building has the correct u-value (and to complies with all the other regs). Some people choose to provide all the calculations and details upfront for the council to approve. Others take the risk of cracking on and getting the council to sign it off once built.

 

But in no way does either route mean the u-value is "not relevant". Indeed, on a Build Notice it is arguably more relevant, since any shortcomings will not be discovered until the building is finished. Somebody needs to know what the u-value of the wall is, and that somebody needs to be liable to you for replacing it if it's not compliant.

 

If, as you have now said, your builder has told you an exact wall thickness he will be using, that he knows meets the regs (and personally I'd want that in writing), then stop arguing on here, get out your ruler and your pencil and start drawing.

 

If your builder has not told you an exact wall thickness, then if he's responsible for the building regs compliance you need to ask him to do so. And then get out your ruler and pencil and start drawing.

 

I don't think I can find another way to word the same advice, so it's very unlikely I'll be posting again on this thread.