Grand designs passivhaus premium

[Joeboy]

Did anyone watch it?. Loved the spray seal for cracks but was revolted by the size of the place. A £1,500 catflap and a £20,000 skylight?

Also, how can a roof that vast be generating only 270 kWh per day (maybe it was the 1st March). Does the average home really only use 8kWh power per day and how can they be limited to only 2.5 x that in export?

Answers on a postcard please.

Finally, £1.25M and only 1/2 finished.

Impressed with the spec though, self generate 4X your consumption.

[Mart]

Hiya Joeboy. Haven't watched it yet, but the info at the end of the last episode intriqued me, as I hadn't heard of passivhaus premium. But the mention of building a powerstation (in the clip), suggested to me a net exporter.

I have nothing against reduced energy consumption, and efficiency, who would, but it has to be sensible, rational and economic. As an extreme example, would it be better to build the same house, but leakier, with far more PV, and perhaps an investment in a wind farm, for the same cost or less? Have to say that if for example it would cost me £50k to make our house super efficient, I'd probably spend it instead on more RE and battery storage, if that would be a net gain - more leccy left over from the extra gen, after extra heating of house.

Regarding the 8kWh figure, obviously I haven't seen the reference yet, but that sounds about right for domestic leccy (not total energy, nor for BEV's) at around 3,000kWh pa. I think the UK household average has been steadily falling for over a decade. I recall 3,600kWh, and 3,200kWh as averages, but I'm not sure what the current figure now is.

Our house steadily dropped as we improved things, with consumption (not import, as we have PV too) reaching about 3,000kWh pa in 2017 and 2018, but bthen started to rise a bit as we began to use an A2A unit (then a second in 2021), and then more from 2019 as we moved from ICEV's to BEV's. It's now about 6,000-6,500kWh pa.

Just spitballing out loud, but my sister got 3phase for about £2k, and 10.3kWp for ~£8k (2yrs in and averaging 11MWh pa). So, for £100k, they could probably install 50kWp ground mount, and 100kWh of battery (or more), and export at ~11kW (with some serious curtailment from around mid day in the summer*). Purely from an economical point of view, that might be greener? I really don't know, and I'm not arguing either way, just a thought exercise.

*Batts mostly emptied ready for PV, then exporting 11kW, with ~40kW of gen, so batts filling at upto 30kW, till curtailment needed.

[Moxi]

I watched it but more and more of the designs are disappointing and these days it seems the norm not to be finished ????

I much prefer the designs like the woodsman's home made from his own woodland and skills - that to me is the pinnacle.

For many of the shows it feels more like a crass exhibition of personal wealth combined with underwhelming project management capabilities.

Maybe that's why I only watch the new shows here and there and often on catchup ?

Remember the garage sized plot in London where the young couple built a family home on a smaller budget with a bath that slid out under from the bed ? They had a very large rolling sky light that the chap designed the carriage for and that wasn't anything like £20,000. The old adage that a fool and his money are easily parted springs to mind.

Each to their own I suppose and I hope they, like many others finally get it finished and move in to enjoy it.

My cheap inverter arrived last night so I will try to get one of the new panels running on a temporary frame sometime over the weekend in between parties and rain showers.

Have a great day everybody, I will enjoy a binge read of the days comments when I get home later.

Moxi

[Bugtownboy]

I watched it but more and more of the designs are disappointing and these days it seems the norm not to be finished ????

I much prefer the designs like the woodsman's home made from his own woodland and skills - that to me is the pinnacle.

For many of the shows it feels more like a crass exhibition of personal wealth combined with underwhelming project management capabilities.

Maybe that's why I only watch the new shows here and there and often on catchup ?

Remember the garage sized plot in London where the young couple built a family home on a smaller budget with a bath that slid out under from the bed ? They had a very large rolling sky light that the chap designed the carriage for and that wasn't anything like £20,000. The old adage that a fool and his money are easily parted springs to mind.

Each to their own I suppose and I hope they, like many others finally get it finished and move in to enjoy it.

My cheap inverter arrived last night so I will try to get one of the new panels running on a temporary frame sometime over the weekend in between parties and rain showers.

Have a great day everybody, I will enjoy a binge read of the days comments when I get home later.

Moxi

Totally agree.

I’d prefer the programme to be more aspirational/inspirational for the average family - whatever that is.

And perhaps focusing more on improving existing dwellings and/or repurposing existing structures or brownfield sites.

Intend to watch it, but it does leave me disappointed and uninspired.

I think the worst part is always the budget/project management - how many are able to find additional £X,000’s as they go way over budget.

Most of the designs, I feel, are never going to be ‘homes’ just a legacy to someone’s vanity project.

[Tinbum]

I enjoy the program but I feel its getting less and less into the actual detail of the actual build and more and more a story. For example a recent program mentioned about replacing all the steel work and something about welds but no real detail of the problem.

[nowty]

Regarding the 8kWh figure, obviously I haven't seen the reference yet, but that sounds about right for domestic leccy (not total energy, nor for BEV's) at around 3,000kWh pa. I think the UK household average has been steadily falling for over a decade. I recall 3,600kWh, and 3,200kWh as averages, but I'm not sure what the current figure now is.

The latest annual average for leccy recently agreed by OFGEM is 2,700 kWh down from 2,900 kWh.

Or 3,900 kWh down from 4,200 kWh if your on E7 with a split of 58% peak and 42% cheap rate.

For completeness, Gas is 11,500 kWh down from 12,000 kWh.

https://www.ofgem.gov.uk/sites/default/ ... Letter.pdf

[AE-NMidlands]

I enjoy the program but I feel its getting less and less into the actual detail of the actual build and more and more a story. For example a recent program mentioned about replacing all the steel work and something about welds but no real detail of the problem.

We have given up watching it, but for some inspiration see https://www.ecology.co.uk/projects/
I think the programme would be improved by following some of the builds that the Ecology BS fund. We saw the nice flats in Portobello being built on a patch of brownfield land...
one story (https://www.ecology.co.uk/projects/rob- ... in-the-uk/) says

UK’s 1st Certified Passivhaus Plus Self-Build Home
Rob and Karin set out to build a comfortable family home that would improve their quality of life as well as reduce their carbon footprint.

They chose the Passivhaus Plus standard for their build, which combines the Passivhaus approach to minimising energy requirements with on-site renewable energy generation. This means that the building produces more energy than its occupants consume, both for heating and electricity. Passivhaus buildings have high levels of insulation and airtightness and maintain a comfortable temperature all year round, resulting in much lower heating bills than conventional property.

Traditionally, Passivhaus construction has been seen as significantly more expensive. Rob and Karin wanted to demonstrate that it was possible to build a Passivhaus for little more than the cost of building a standard house. They set out to complete their build on a budget by using materials and techniques familiar to British builders. Everything in their house except for the windows, airtightness membranes and ventilation system can be found in a typical builder’s yard.

In order to finance their project, the couple needed to find a mortgage lender that understood both the challenges and the longer-term benefits associated with a Passivhaus self-build. They spoke to the mortgage team at Ecology, which has a well-established track record in supporting Passivhaus projects and shared their enthusiasm for low-impact self-build.

The result has been a practical family home, which maintains a steady temperature throughout and produces more energy than it consumes over the course of the year. This combination of low energy demand and high solar production, from 38 solar panels, means that they will receive a net income from the electricity generated.

A

[Paul_F]

Hiya Joeboy. Haven't watched it yet, but the info at the end of the last episode intriqued me, as I hadn't heard of passivhaus premium. But the mention of building a powerstation (in the clip), suggested to me a net exporter.

As some of you may know, I'm looking to knock down my current house (1930s bungalow with neither wall insulation or foundations) and build a new house. This has been a bit of a saga with planning, but the feedback from the planners has been if we move it slightly we'll get permission. Should find out if they really mean it in the next month or so.

Passivhaus is part of the spec for the design, mostly as frankly it's the minimum standard new houses should be built to today. As for Passivhaus Premium, that comes from updating the specification to take account for the fact that more people are fitting PV - trying to encourage it while stopping them from gaming the system.


In our case, the footprint area is 113m² (measured from the drawings, so not exact), meaning we would need between 10.2 and 17 MWh of generation per year to hit the standard depending on our PER demand. I think there's room to generate up to 14 MWh/year, and as drawn at the moment the PV would generate 10 MWh/year.


It's important to note that for a new house in-roof installation is pretty cheap: scaffolding is already up, you're sorting electrics anyway, no VAT, etc. Allow for the fact that you don't need to pay for tiles, and you want to stick on as much as you can fit.

PER demand should be very low, but since I'm not 100% sure on the calculation I'm not going to be doctrinaire about standards until we get an answer on it. Heating and hot water will be from a heat pump (possibly GSHP if the costs are right - we have a huge garden and low heat demand), heating would be via underfloor pipes in the ground floor slab (=> very low flow temperatures) and we'd have a heat exchanger on the shower hot water and run the dishwasher on hot fill. That all gets us very close to premium for a very normal house where the only giveaway is the thick walls.

[Ken]

Remember its television.

I thought it very weak as no mention of heating/temp control or HW.
The PV export was limited by grid.
In winter one can have zero PV so clearly the 4X mantra must be over the yr ? Get the cert with electric bikes and buy the EV later.

[Tinbum]

As some of you may know, I'm looking to knock down my current house (1930s bungalow with neither wall insulation or foundations) and build a new house. This has been a bit of a saga with planning, but the feedback from the planners has been if we move it slightly we'll get permission. Should find out if they really mean it in the next month or so.

I have planning to build a new house and then knock down our old one but haven't started yet due to 'the gift that keeps on giving' - Long Covid. I am going to build to passivhaus standards but not bother with the red tape of certification.