mads

Yes I have and have put it in the tender spec. However, I don't want the MC to be using it as a get out of jail free card and actually get to as low as possible before we apply it. Also, I agree with you about it being a bit of a cop out so thought I would ask the collective wisdom here as to what has been targeted/achieved before I respond back and ask the SAP consultant to try harder.

Hey Nick, I will be installing MVHR throughout and removing trickle vents from the windows. There is no letterbox though there is a catflap planned (https://www.thepetflap.com/passivhaus-pet-door/) Not intentionally building to NZEB but there is a desire to build to the best standards we can afford. Already have a 30Kw PV array, solar batteries, ASHP, MVHR, UFH planned. The cavity is 150mm.

Hello all, the architect has forwarded me a response from the SAP consultant and wanted to gauge what target (and actual) people have had for air tightness in a traditional block and brick masonry build? what the SAP consultant said…

@Gus Potter, thanks for your reply. Now got the report back which I have attached. Also attached some floor plans and elevations so you can see what the foundations need to support. Any advice/feedback is appreciated. BH Forum.pdf Geotechnical investigation report 0- redacted - mads.pdf

Yes, I did and have also shared with the architect but apparently not helpful. I need to go back to the company and see if can get anything more but thought I would ask here in case others have sussed this before.

How did you fit them? Do you have any architect diagrams that I could share with mine to give him a different way to look at this?

Hello, Following on from my post asking about external blind suppliers, I tasked the architect with incorporating some external solar blinds into the construct (brick and block with 150mm) so that the boxes are hidden rather than being face fixed to the windows. He has come back with the following response: I wondered if anyone has managed to do this? Thank you, Atif

As others have said, where is the 25mm max limit coming from? Re: ENT tubing, it is cheap but it is not smooth internally so could find pulling cables more tricky as can snag. I am having posi joists fitted which will allow larger conduits run and will fit smooth inner to prevent snagging.

Thanks for sharing. I'm interested as to why they then mandate it? And could it be different if the tank size was doubled?

So some modelling shows... Over 10 years, based on a 5% YOY price increase (I think this is too low imo), the fresh water supply cost for my scenario would be: 2025/26: £304.56 per annum 2034/35: £472.47 per annum The total over the 10 years would be £3,830.72 vs £3,045.60 if the costs were to remain static. Looking at just today with the current costs, the ROI timeframe is 26.6 years Looking over a 10 year horizon with the above increases, the ROI timeframe reduces to 21.1 years Over a 20 year horizon with still a 5% YOY increase, the ROI timeframe reduces to 17.3 years

£348 for the year vs £304 for ST Water on a like-for-like

Thanks. Though I have to say that my exercise presumes the costs stay the same for the entirety. We know that the cost of water supply is going up, with numbers of around 36% over the next 5 years. If I assumed a 3% YOY increase to the fresh water price, that goes up to 360 pence per m3 in 10 years. At that cost, it could shave off around 8-9 years from a ROI timeline. I need to do some financial modelling to see what this might look like over a 10-15 year horizon as I suspect it will be different to the static view I have started with.

Garden is 1 acre which will be 0.4 acre lawn, 6-8 sqm vegetable patch, medium to large greenhouse and 6m diameter pond to keep topped up, plus plants and hedging so expect fairly high use - in-laws are avid gardeners too. When I sent my request to suppliers, they came back saying I need a 5,000L tank but to be on safe side for droughts then consider a 7,500L one. I was going to get a 10,000L as I also have outbuilding roofs which I haven't factored into the water capture calc. Water cost is actually m3 - had the wrong units described and have corrected in my file. Doesn't change the calcs. Waste cost doesn't apply to me so I would zero it out. I included it in case I share this with anyone and they may need to use it due to connection to mains sewerage. For me, the ROI is around 30-40 years so one to think about in terms of capital cost outlay. Was useful to do the exercise and hope it helps others. I had to do a few iterations to get to a point where the ROI time frame balanced out. The replacement pump cost drove it up and I would look to see if 3 years is too frequent.

Kingspan Klagster 4,600ltr system was mentioned. Re: long dry summers, I think this is where making sure you have a high volume tank is important so can store more during the shoulder months when we do have rain.

I decided to create my own calculator on how much I could save on water by RWH. Here is the calc (I included a waste water section though not applicable for me). Happy to upload the file for others to use for themselves, if helpful. I have only done it from a water consumption and waste water perspective. I have not factored in electricity costs (as I personally feel this is negligible and most of us will have PV) but have included replacement pump costs.