Adrian Walker

By "reputable", do you mean that they have a reputation for not doing it correctly? Adrian

I agree with @Dreadnaught, using a virgin roll of cable means that there is lot less waste and it's relatively easy to terminate, and if you don't want to terminate, most electrician do termination and most importantly testing, not just continuity. Damaged cables don't perform well. That said YMMV

I use this one - https://re.jrc.ec.europa.eu/pvg_tools/en/

Have you considered Bamboo as a cladding option? https://www.moso-bamboo.com/

Understanding your electricity bill https://www.nationalgrideso.com/electricity-explained/electricity-and-me/my-electricity-bill is worth a read

Totally agree. a fabric first approach is the way forward

If you have the space, 3m x 3m, they can put in on the ground for a lot cheaper cost.

Railing on both sides is governed by the stair width.

Welcome to BH

Fantastic! Thank you very much for sharing your DaAS. I'm sure that many people on here will read and re-read it before making a planning application.

Someone on Grand Designs used a Lewis/metal deck and concrete in with a timber frame. The real benefit of a concrete floor is lack of noise. Velox make a concrete floor/ceiling system that uses woodcrete modulars which are 500 x 2000mm - https://icfsystems.co.uk/floors.html

This is normally the case with Architects but you should check the T&Cs. If you wanted them you needed to state that in the contract.

When were these Deeds written?

The Passivhaus Handbook: A Practical Guide to Constructing and Retrofitting Buildings for Ultra-Low Energy Performance By Janet Cotterell and Adam Dadeby is a really good book.

I think you will find that the "self certify your passive house" is actually referring the the AECB Standard (https://aecb.net/aecb-building-certification/)which can self certified. If you need a mortgage then if you meet either standards (PH or AECB) Ecology will give you a discount once completed.

Velox also has a flooring system - http://icfsystems.co.uk/floors.html

Congratulations of finding an open minded and willing to learn Architect 🙂

If would suggest that you find an architect or architectural technician that has some experience and knowledge of PH design. Most don’t and if they don’t understand the 5 Pillars of PH design then you will spent a lot of time and money educating them.

All of the Velox blow outs that I have seen is because the incorrect nozzle has been used at the end of the pump and/or the mix incorrect. Your experience is obvious very different which is fine.

Vents are noisey when the airflow is too high, caused by not enough vents and/or diameter small ducting. Ducting is relatively cheap and a small price to pay for a silent MVHR system. To test that an MVHR system is doing its job, measure the CO2 (not CO) levels in each room.

I totally agree

Spend your money on insulation first

Since you already have underground ducts buries, I would run some cable in to the cavity. Make sure you have a good sketches and photos of what you have installed. A tape measure in the photos will help later to find them.

I use this one - https://joint-research-centre.ec.europa.eu/pvgis-photovoltaic-geographical-information-system_en

I do hope that you don't ask all 22 companies to quote, as that mean that the other 21 will have to pass that cost onto other customers. Accurate quotes take time and cost which someone has to pay. That said I don't (and hope) that you are just buying on price only. Enjoy your build