Nick Laslett

Depends on how the Bass Management is handled. It is better to have an amp that splits the bass frequencies from the rest of the music signal and sends that to the subwoofer. Most standard speakers do not have very good handle on the bass frequencies unless they are big floor standers. Audioholics YouTube channel and website will have an article on this topic. Or visit Richer Sounds and talk to them about what you are trying to achieve. The challenge is you can end up with a system where the subwoofer and speakers don’t blend well together, and you don’t have sufficient controls to adjust this. *Edit. A quick google tells me the Cambridge Audio CXA81 has very limited bass management. In this case you would set the low pass filter on the Subwoofer to ignore frequencies above a certain value. https://supportarchive.cambridgeaudio.com/hc/en-us/articles/17968357221661-How-can-I-connect-a-Sub-Woofer-to-the-CXA61-81-81-Mk-II **Edit2. Both amps will be fine. You need a Subwoofer with good controls, so that you can set the crossover to blend with your main speakers. Somewhere in the chain you need a way to manage the bass frequencies.

@flanagaj, my standpipe was the first step in my plumbing journey. This is what I ordered to satisfy the Anglian Waters stand pipe requirement Polyfast 32mm to 25mm Reducer https://www.bes.co.uk/32-mm-x-25-mm-polyfast-mdpe-reducing-coupling-compression-9859/ Brass Stop Cock - 25mm MDPE to 15mm https://www.bes.co.uk/brass-stop-cock-mdpe-x-copper-25mm-x-15mm-10484/ JG Speedfit Tee https://www.bes.co.uk/jg-speedfit-push-fit-tee-15mm-7080/ Brass drain cock 15mm https://www.bes.co.uk/drain-cock-type-a-15mm-brass-21822/ Brass Double Check valve 15mm https://www.bes.co.uk/double-check-valve-non-return-15mm-dzr-8151/ 90° tape connector elbow https://www.bes.co.uk/1-2in-bsp-x-15-mm-bent-tap-connector-jg-speedfit-push-fit-7090/ Brass Bib Tap 15mm https://www.bes.co.uk/hose-union-bib-tap-1-2in-9317/ I also had to get tools, a piece of 15mm barrier pipe, piece of 25mm MDPE pipe, pipe inserts for 15mm, 32mm and 25mm. There is a very good thread on here already, which I based my purchases on, I will try to find it. *Edit here they are:

Not sure which approach is the best or the trade offs. I did my own install, so rigid intake and exhaust. Then rigid to the supply & extract manifold boxes, then radial semi rigid to all the rooms. I could not have got my head around a rigid branch system for the whole house. All of the runs from the plant room to the rest of the house are already very congested. To much pre-planning, with too many unknowns.

Don’t let them intimidate you. Worst feature of all forums is loud voices crowding out debate. There is no one way to do most things. Best thing you mentioned was the builder had a contractual obligation to hit a certain ACH. Anyway congratulations on finishing your own build. I’m sure you are benefiting from excellent airtightness, and the freedom to fix anywhere on the walls without having to worry about puncturing a membrane or the screws getting loose over time. *Edit: What did I use for my airtightness strategy; ICF walls, Siga Wigluv & Fentrim tapes, Illbruck FM330 expanding foam (love that stuff), Triton TT gas and water liquid membrane around windows, ProClima Intello Plus for dormer cheeks, ProClima & Siga pipe sealing grommets, one for outside tape, the other for water softener pipe. Actually getting very close to air testing on my build, will be pretty disappointed if I don’t hit 0.6 ACH as the materials cost a fortune and the time spent was excessive.

@Gus Potter, thank you for the model. If it is of interest here are some specifics from the data sheet for the Eurotec screws. https://app.nextpim.de/Cloud/6118eacef55a4834b44c3623/a3ba70a2-990d-432c-fb8c-08d79e6bb09c/Product_data_sheet_Blue-Power_Systemschraube_EN_06_2023.pdf For fastening timber substructures to concrete. When the system is installed on façade insulation, the insulation absorbs a proportion of the transverse forces. The insulation product must therefore have a compressive strength of at least 50 kPa at 10% compression. Static Values For fixing in Concrete C20/25 Tensile load bearing capacity = 2.5kN Shearing load bearing capacity = 0.75kN The manual from the ICF supplier doesn’t really go into any great details about fixing external timber battens. The two biggest challenges were finding a concrete screw long enough to go through a 25mm batten and 100mm EPS, + 50mm minimum fixing depth, and the need for some kind of external weather rating. The Eurotec screws are rated for C4 environments and appear to be designed for going through 100mm+ of insulation, then affixing into concrete. One of the things I liked about the Thermohouse ICF blocks was the specification of the EPS, they have a compressive strength of 150 kN/m2 at 10% compression, EPS density of 24kg/m3.

I feel your pain. In our utility room we went from flat power floated concrete floor, to uneven slate tile floor. The kitchen fitters had to scribe the front of the wooden cabinets to make them level. Even getting the trades to do what you want is an uphill task.

I used a mix of 25x50mm and 25x30mm coloured roof battens. I followed the TDCA guidelines, but I was fitting thermowood timber. I actually bought the full book in the end, but I think the free one covers nearly everything. https://www.tdca.org.uk/publications/the-timber-cladding-handbook/

@MortarThePoint, here is the thread I have book marked, where both NickfromWales and PeterW opined. They both suggest 50mm for smoothest long term functioning.

Besides the superstructure, we have done most of the build ourselves. We stood down our architect after the foundation design and the building regs submission. This was many months before we broke ground. We had the CAD versions of our drawings and my wife had also drawn the house in SketchUp. (Prior to this she had made a physical model.) We were very confident in the details of the build. Because every part of the superstructure came from one supplier, their technical manual covered any questions we might have had. Over the course of the build we’ve had every kind of arrangement you can think of; from a day rate quote by text, to a detailed contract with phases and full materials breakdown. Some have come to visit the site and made a number up on the spot. Sometimes we’ve already had the materials, others they told us what to buy, some bought the materials and passed on the cost. Most recently a trade wanted the first 1/3rd paid up front to secure the booking. We have taken a pragmatic approach, and tried to work with trades that could see what we were trying to achieve. 90% of the time it has been a great experience. I try to understand how to do each task, which I hope means that when I talk to the trade they respect the job I’m asking them to do. There is no rhyme or reason behind the pricing, the spread between 3 quotes can be 100%. The story of each trade, is really the story of the build. Stuff goes wrong, not sure if excessive blame does anybody any favours. Our interior door supplier went bankrupt, taking the deposit for 11 doors. The insulated foundation UFH was not installed as per the drawings, I only found this out much, much later. I liked the lad that did the work, and he also managed the foundation pour and the power floating. So overall I was pleased with most of his work. The foundations were level and the concrete smooth. Your build is not far from mine, if you want a sounding board, happy to lend an ear, send me a PM. Please appreciate that my knowledge is puddle deep, this is my first build and this forum is the crutch I lean on.

You have hit the nail on the head. You face an unsolvable conundrum. You don’t know your airtightness until you finish the build, therefore you don’t know your heat loss, so how can you size your heat pump. And for low temp heating in an insulated foundation you have to put in your UFH pipe loops at the very beginning of the build process. You essentially have to take a huge leap of faith that it will all work, and commit the cost and materials on that promise. Insulated foundation, MVHR ducting, ASHP flow and return. These all shaped my house more than any other factors. I struggled with this dilemma very soon after finding BuildHub. The curse of the more you know, the less sure you are. Ignorance is bliss! Most of my build decisions have been predicated on how to achieve good airtightness, how to reduce ASHP short cycling and how to stop the house overheating. PPHP and a good consultant will solve this, but like every other aspect of the build, if only you could click your fingers and have people you can trust work for you. I only recently discovered that the MBC guys that did my foundation only put in 2/3rds of the UFH piping that was on my LoopCAD drawings. This destroys all of my heatloss calculations and ASHP decisions. How can I go back and undo this, when I can’t rip up a concrete floor and put back the missing UFH pipes? You just have to live with the mistakes.

@LadybuilderLOL, welcome to the forum. Amazing looking project. There are a few Grand Design episodes with similar challenges. I binge watched my hours of that show once I started on this journey. I remember one where they used pre-cast concrete panels, which looked like a neat way to solve some problems. We have an ICF build in Suffolk, near Bury St Edmunds. We used Thermohouse, they supplied the materials and built the superstructure. Very happy for site visits if you are interested in finding out more about their products and our experiences. https://thermohouse.co.uk/self-build/ We visit Hertfordshire a lot, my wife is from Berkhamsted. We are still finishing the internals, but there is now light at the end of the tunnel.

For my shower handset connection I used the Alfie fixing which I saw on a Skillbuilder promotional video with Robin Clevett. There is an option for Hep20 compatible connection.

Is there anything specific you have done to insulate the main garage door?

@MortarThePoint not done much silicone yet, just the plant room where I used Mapesil AC acetic silicone sealant for sealing between floor tile and wall. https://www.mapei.com/gb/en/products-and-solutions/products/detail/mapesil-ac Only been down for a couple of weeks, but was happy with the tooling of the silicone and the final finish. My experience with the hybrid MS polymer products like CT1 or OB1 is that it is very difficult to get a good finish. I did try Sika EBT+ to seal the bath in my rental property, I would not recommend EBT+ for this purpose. The main difference between the two DOW products is the 785N is suitable for natural stone materials and won’t stain them. Mapei has the same distinction between there two silicone sealants.

@Thorfun, I prefer OB1, but I believe that CT1 is the precursor product. I have a Sika Trocal PVC based membrane on my flat roof. My roofer used OB1 to fix the up-stand of the Trocal Membrane to the slate roof tile. My roof has been on since March 2022, no issues so far. Looking at the specs, OB1 works with PVC and I believe Alwitra is also PVC based like Trocal.