'Fabric fifth' retrofit policy. A really interesting read.

[Square Feet]

I was really interested to read this article in the current Passivehouse+ magazine.  It turns 'fabric first' on it's head and argues that installing an ASHP is more important than the full hit of retro-fitted environmental measures ie wall and floor insulation, triple glazing etc. It chimed with me as I recently sold a flat I had bought to renovate after getting completely bogged down in retro-fit eco options. I was extremely concerned that much of what was proposed by the organisations offering this service would stop the building from breathing properly and store up considerable problems in the future. Of course, by then they would be well clear of the picture having trousered a big wedge of government cash and I would potentially be left with an unmortgageable property and a hefty bill to put things right.  

 

I do understand the argument that an ASHP won't work efficiently in an otherwise inefficient building, but I do think it is a lot more nuanced than what it is being sold as. I think I'd agree that we have made it too difficult for many people to retrofit to a decent standard, which coupled with a dire labour shortage in the relevant trades, means that progress is glacially slow (pun intended).

 

https://passivehouseplus.ie/magazine/insight/fabric-softener

[SteamyTea]

No surprises there.

Except how long it has taken the industry (passivhaus/passive house) to realise where the quick and cheaper gains are in retrofitting.

[saveasteading]

32 minutes ago, Square Feet said:

installing an ASHP is more important than the full hit of retro-fitted environmental measures ie wall and floor insulation

 

It's good to hear that being suggested in a vessel that has been so nerdy on these other matters to beyond what is economic, for so long.

 

It's never that simple of course.... construction, door heights, and such.

The reality is that when our oil burner failed during the winter, we could get a new boiler in a week but an ashp would not have been realistic.

 

For a remodelling or upgrade though, I might settle for 50mm of insulation where possible, and ufh or big rads.

With solar and batteries.

 

And/or air to air units in some rooms, permeating elsewhere. 

 

BUT how many have the knowledge to think it all through?

 

The heat loss is the same whether ashp or boiler so it's well worth considering. 

We just filled the oil tank. Gulp.

 

[saveasteading]

9 minutes ago, saveasteading said:

air to air units in some rooms, permeating elsewhere. 

I'm a convert to these having just put 2 into a Spanish place for cooling, but also heating at over 4 x efficiency.

So simple, not too noisy, and very direct and instant.

€900 per biggish room so in a small house that could be a simple solution.

[JohnMo]

1 hour ago, Square Feet said:

I do understand the argument that an ASHP won't work efficiently in an otherwise inefficient building

But that argument is utter rubbish in reality and has been for a number off years since the grid started to be decarbonised. You can heat any building with a heat pump and it can be the cheapest heating when compared to gas or oil, and emissions lower also.

 

Only things that are important is heat pump is sized correctly and emitters  are sized for a low low temperature. Then it's basic science heat out matches heat in.  Add a ToU tariff and battery you savings can be huge in cash terms also.

 

In CoP terms a poor performance building can give way better CoP than a high performance one. Example our current average daily temp is around 9 degs, but the heat pump only runs for a 1 to 2 hour stint, gets a CoP of mid 5s while running, but then spends the next 20 odd hours off consuming standby losses, and although small bring the CoP down on a daily basis. A poor performance building would be taking heat all day and keep at a high CoP level all day, as long as the emitters are sized well.

 

A2W need good sizing of heat pump and CH system, A2A needs only the heat pump sized correctly.

Edited 11 hours ago by JohnMo

[JohnMo]

1 hour ago, Square Feet said:

think I'd agree that we have made it too difficult for many people to retrofit to a decent standard

Think it can be pretty easy, just let technology make it a smarter install.

 

You select a heat pump, you install with an Adia Thermal kit (https://adiathermal.co.uk/) and that's about it. No changes to heating system at all initially apart from tying in a box of tricks.  After a couple of weeks it tells you what radiators could be upgraded to save on running costs, it's then optional to do it or ignore.

[Square Feet]

23 minutes ago, JohnMo said:

Think it can be pretty easy, just let technology make it a smarter install.

 

You select a heat pump, you install with an Adia Thermal kit (https://adiathermal.co.uk/) and that's about it. No changes to heating system at all initially apart from tying in a box of tricks.  After a couple of weeks it tells you what radiators could be upgraded to save on running costs, it's then optional to do it or ignore.

That's interesting, thanks. Do you have a rough idea of the cost of it? I've been on their website but it's a bit opaque as they want you to get your installer to fit it. It does look cool though. 

Edited: Never mind, I've found it here. https://midsummerwholesale.co.uk/buy/renewable-heat-accessories/adia-thermal

Edited 10 hours ago by Square Feet

[Mike]

An interesting article, these are the key elements for me:

 

...I don't think Banks pays nearly enough attention to airtightness, ventilation, humidity control and health. And he doesn't even mention what should really be Step 1: an audit and a plan to determine the best balance of "enough fabric to improve comfort and health" and heat pump sizing.

 

With Passive House Plus being Irish (not sure about Nigel Banks), maybe the fact that most homes in Ireland are heated by electricity, rather than gas, makes choosing a heat pump a no-brainer anyway.

 

FWIW, without first getting an approved audit, it's not possible to get a grant for a deep renovation in France.

 

[JohnMo]

Ireland are heated by electricity

Was watching "Blue Lights" last night and it is set I believe in Belfast, a row of houses in the centre of the city and the house they enter at the rear has an oil tank in a small back yard. very strange when you compare the the rest of the UK and the intensive gas network and only houses in the country would be oil heated

[Roger440]

7 hours ago, saveasteading said:

 

It's good to hear that being suggested in a vessel that has been so nerdy on these other matters to beyond what is economic, for so long.

 

It's never that simple of course.... construction, door heights, and such.

The reality is that when our oil burner failed during the winter, we could get a new boiler in a week but an ashp would not have been realistic.

 

For a remodelling or upgrade though, I might settle for 50mm of insulation where possible, and ufh or big rads.

With solar and batteries.

 

And/or air to air units in some rooms, permeating elsewhere. 

 

BUT how many have the knowledge to think it all through?

 

The heat loss is the same whether ashp or boiler so it's well worth considering. 

We just filled the oil tank. Gulp.

 

 

You are right, its not simple. Everything is inter related. Moving to ASHP means changing the emitters. So, likely, definitely in my case, highly disruptive. Plus, as already noted by Johnmo, sizing is important. So, really, you need the house to be in its "final" state from an insulation and air tightness perspective or at least know what that will be.

 

If you do the heatpump first then significantly improve the house, your heat pump/emmiters will be oversized.

 

Add in getting tangled up in things like solar and batteries, all sorts of building control stuff, shelling out 4 figure sums on "reports" etc, it rapidly becomes a major project that needs to be done in a logical order to get an optimum result. And i understand most of it. The average layman hasnt the first idea.

 

Which of course, leads to ones wife saying, why are we bothering? Easier just to leave it as it is. No disruption, no major expenditure. Keep filling the oil tank, and seal up the obvious drafts, and call it done.

 

I dont want to do that, but the scale of task is significant, costly, and disruptive over a significantly long period of time. Makes you wonder?

[JohnMo]

5 minutes ago, Roger440 said:

Easier just to leave it as it is. No disruption,

First step is really optimisation of what you have. Get the flow temps as low as practical with long run times. If practical for boiler move away from S and Y plan to priory demand hot water with 2 flow temperatures (W or X plan). in most part little or no plumbing changes just efficiency improving, and some simplification by having more system open for longer.

[Roger440]

9 minutes ago, JohnMo said:

First step is really optimisation of what you have. Get the flow temps as low as practical with long run times. If practical for boiler move away from S and Y plan to priory demand hot water with 2 flow temperatures (W or X plan). in most part little or no plumbing changes just efficiency improving, and some simplification by having more system open for longer.

 

Ive already screwed down the flow temps as far as i can and still keep the house warm at -10 and reduce cycling as far as i can. It might even be condensing, though that seems really hard to achieve on an oil boiler, even if, in theory it will do it.

 

Boiler not clever enough for differing flow temps.

 

Currently consuming 1600 litres a year. 

 

Most of the windows are knackered so i will be doing those anyway. 

 

Im all for doing everything, my wife rather less so. Particuarly the moving out of the house and into the barn for 9 months to do it all in one hit. 

[JohnMo]

6 minutes ago, Roger440 said:

Particuarly the moving out of the house and into the barn for 9 months to do it all in one hit. 

We just sold our 1830s house and built a new house, way easier and didn't take much longer.