Sophiae

Yes building a cavity wall and now final choice is between beads (cheaper) or the Celotex Thermaclass 21 T&G (expensive) but is also full cavity fill “according to manufacturer”. Setting the financial aspect of things aside, and based solely on other numbers which one to go for to guarantee longer term? Celotex_Thermaclass_Cavity_Wall_21_Install_Guide.pdf

Are you still happy with your choice of beads? How are your heating bills been?

Hi My current plans are done on CAD and they are produced in 2D pdf forms. For building regs, would it be ok to continue to work on that or redraw on Revit? Will BCO have a preference? In real life, does it bear any weight? How easy is it to convert CAD to Revit?

Feeling more confused now. like the idea of all of them but essentially it is down to the skill of the brick layers. not sure how comfortable that makes me feel to have to rely on other peoples’ work ethics when some have already failed me big time. I’ll read again and check the feasibility of each if all 3 options can achieve the same U-Value

On another note. How would I calculate how much I need? I suppose no harm in punching the numbers.

Too expensive for my budget

Yes that would be the plan, but as I get building regs done for approval, do you believe they will give me the same U-value for the new walls as the new regs?

I read a few articles and seen the videos and I have to agree they are a better option for all my pre-existing cavity walls with no insulation. Do you believe they are a good option for my new extension walls?

I don’t have one. Shall I ask him to provide one?

All feedback much appreciated Calculations.pdf

That’s exactly what happened. I asked 4 SE and each one came with a different design that the other, though 2 of them came very close. i’ll attach the maths.

Agreed, and that’s the situation most people are in. i started this journey thinking I would get 4 meters extension under PDR. Found out the wall will nearly come to 40cms with all layers to be complaints and fit for purpose, taking those from my inner space. So now left with 3.6 meters, and have to find furniture to fit. This is why I am trying to see what will work instead of going back to application process.

What do you think of these in replacement? i also have the full calculations using Tekla as well. New Proposed SE.pdf

It’s not the bifolds. It’s the Beam1. it’s massive.

So if a friendly chat hasn’t done the trick and I wasn’t able to recover my money, how would I proceed next?

Hi John i am new here too but been posting here and there seeking knowledge and advice. I am glad you are here and may very well ask for your wisdom down my journey. i am trying to make a home for me and my little one and the journey hasn’t been easy so far. Back to design 😞 but the people here are extremely helpful and inspiring and I can’t wait to share my journey as I move along from my first few steps.

Thank you so much @Olf. I am starting with the extension first as I need a place to sort of use whilst I embark on the rest of the property. I very likely will need to go as deep as I need to get it all level with the extension and guarantee the 150mm insulation. The plan is to also hire a crusher so that I can recycle everything that comes out from the concrete and add extras rather than use skips and buy all new. If you don’t mind I will keep writing here seeking further advice as I start.

Isn’t rockwool not a great insulation compared to rigid PIR?

What are batts?

What is that? Any pictures to understand?

Am I ok to use the 3.6N on the inside leaf with a bean sitting on top? I’ll have a look again at the SE’s design.

Here is another one

Apologies for the intrusion (me again), didn’t want to start a new topic as this one may very well address my ongoing dilemma. so working on building regs and trying to optimise my drawings and attempting to make better choices for the structure. The SE specified 7.3N blocks (u-value 0.18) for the extension cavity wall. Initially he proposed a block/brick cavity wall and I was ok. With new regs requiring a lower u-values I thought to get the thickness a little smaller we can use this make up: 100mm blocks rendered external leaf 50mm cavity 100mm PIR insulation 100mm blocks internal leaf 12.5mm plasterboards The problem I am reading here is that placing the PIR boards can be a problem with heat loss? What are the other alternatives that are with similar budget? what does everyone think of a solid block wall with external insulation instead of the cavity? Would it work better? Cost? U-Value?

I am likely to follow your advice on this, however I would like to have UFH throughout the property, I can’t have radiators for child safety reasons. Do I have to dig all rooms together? I mean I won’t be living there but was thinking of the work load but the space/time. Would it all be possible to dig all with existing partition walls in place?

This is what I am looking at, so if there is any other option as most require about 100mm PIR insulation boards to get below the 0.18.