A2W heatpump retrofit 4-bed SemiD

mcbert

Hi,

have lived in a draughty house before and the way things are going with climate and carbon taxes etc, and as I'm now actively viewing 4-bed semi-d's, I'm trying to budget for upgrading insulation & comfort including a heatpump. There are no suitable new builds in the area.

I'm now viewing typical (if there is such a thing) enough 4-bed semi-d's, C1/C2 BERs, built mid 1990's, 140m2 ish, usually including converted attics.

I understand heatpumps are the way to go, but they provide much lower level heat, so require well insulated and well sealed homes. Well-sealed homes then require DCV or MVHR. Ideally heatpumps have under floor instead of radiators, but if radiators are used, they need to be larger than what would be needed with an oil/gas boiler. With all that in mind, this is what I have so far.

These are items I've thought of so far, with ballpark cost guessed (after any grants, and including VAT). Can anyone give me any feedback on items missed or prices I got wrong?

Pump cavity wall: 2k (after grant)
External wall insulation: 15k (after grant)
New windows and external doors: 18k
Downstairs UFH, new rads upstairs: 15k
Replacement tiling/wood/carpet: 5k
A2W heatpump: 15k
DCV or MVHR ventilation: 7k
Internal plastering for airtightness: 5k
Upgrade roof & converted attic insulation: 5k

Total: 87k

I'm less interested in aiming for any particular BER, I'm more interested in efficiently running a heat pump, including getting the air changes per hour down (I understand 2 per hour that is the threshold to aim for). And the comfort levels in having all of that.

Can anyone give me any feedback?

Thanks!

Calahonda52

Good research thus far

Say more about the work surrounding the downstairs UFH?
Have your targets wooden or concrete floors?
Whats the plan with existing fireplaces?

Converted attics are a nightmare to get retro-ed correctly for airtightness/insulation so your budget is a bit light there, especially if hipped roofs?
They typically have a construction like the attached.
Airtightness in the walls in the space between first and second floor, and second floor and attic will be problematic.

The new Part L Regs may catch you re requiring a certain BER

have you seen this
https://www.nsai.ie/about/news/publication-of-sr-542014-code-of-practice

mcbert

Thanks!

Houses I've looked at have either tiles or wooden floors. I don't have any more details. I know UFH restricts the sort of materials that can cover it but I don't know what else I should be thinking about there. I assume it would be easier to take up wooden floors for UFH compared to kango hammer needed for tiling? Budget wise, is the difference large? I'm also hoping either way, UFH installation will not for example destroy an existing kitchen or do I need to budget for a new kitchen too?

I hadn't thought about fireplace. My options are seal up completely or put in a sealed stove. But even with a stove in there would the full height of the flue need to be sealed in some way? Or each room in contact with the flue brickwork would require extra sealing or other work? Any thought on this would be appreciated!?!

Regarding "Airtightness in the walls in the space between first and second floor, and second floor and attic will be problematic." - can you suggest what I need to think about here? I really don't know what to budget for here.

Many thanks.

Markcheese

That sounds like a f**k load of cash, but I can't really argue with the numbers...
How long would it take to "make back" that amount ?? (aside from the comfort issue "
How much benefit could you gain from improving airtightness around windows, sills, doors, pipe entrances, flues and chimneys (maybe a smoke test as well as a pressure test),
Definitely do your cavity wall, (and extra attic insulation), and then look at heating options, could you go for fan assisted rads.?(or maybe aluminium), or just use air to air heat pump (and ditch rads all together.)
The external insulation would still be possible in the future...but you may well have 50 grand more in your bank account (or 50 grand less of a loan), while still having substantially lower heating costs..

I'm kinda doing this in my head, as am in need of something similar but on a lower budget...

Calahonda52

Its not about payback: if you want paybacks etc then make some financial investments.

For example, look at the super homes web site: 40 to 60k spend by the homeowner and the same by the agency, for what: savings of between 1,000 and 1,500 p/a
www.superhomes.ie
"A SuperHome is an energy efficient home that has implemented all the cost effective and sensible energy measures. These include insulation, air tightness and advanced ventilation. Heat and hot water are provided by renewable energy technologies such as solar photovoltaic panels and heat pumps.

We have retrofitted over 150 houses to a near A3 Building Energy Rating (BER). The average investment by homeowners is €40,000 – €60,000. As well as average financial savings of €1000 – €1500 per annum on oil, homeowners benefit from living in a comfortable, healthier house with better air quality.

In addition, the sequencing of the work is critical, doing stuff in the wrong order is never cost optimal and results in sub optimal results: eg: doing EWI after new windows is horse before cart stuff.

Markcheese

Oh I get that, it's horses for courses, and that comfort counts for a lot, and if you have the money for a new Mercedes s class and want it then go for, I'm thinking more a second hand passat, that hopefully wouldn't stop me upgrading further as I needed to...

Calahonda52

Markcheese wrote: »

Oh I get that, it's horses for courses, and that comfort counts for a lot, and if you have the money for a new Mercedes s class and want it then go for, I'm thinking more a second hand passat, that hopefully wouldn't stop me upgrading further as I needed to...

.
The problem with the analogy is that you won't be adding to the passat to make it a merc, hence the importance of sequencing the work, especially when using modern materials.

Markcheese

Oh I get that, it's horses for courses, and that comfort counts for a lot, and if you have the money for a new Mercedes s class and want it then go for, I'm thinking more a second hand passat, that hopefully wouldn't stop me upgrading further as I needed to...

Wartburg

Calahonda52 wrote: »

For example, look at the super homes web site: 40 to 60k spend by the homeowner and the same by the agency, for what: savings of between 1,000 and 1,500 p/a
www.superhomes.ie
"A SuperHome is an energy efficient home that has implemented all the cost effective and sensible energy measures. These include insulation, air tightness and advanced ventilation. Heat and hot water are provided by renewable energy technologies such as solar photovoltaic panels and heat pumps.

We have retrofitted over 150 houses to a near A3 Building Energy Rating (BER). The average investment by homeowners is €40,000 – €60,000. As well as average financial savings of €1000 – €1500 per annum on oil, homeowners benefit from living in a comfortable, healthier house with better air quality.

What about the additional money of approx 30-35k, coming through the Super Home Scheme grant (or in other words taxpayers´money)???
If I would have to invest just €40,000 myself for this "highly praised" scheme and would save the maximum of €1,500 per annum on my heating bill, it takes 26.67 years to have my invested money levelled with my savings. If I add just 30k of the grant to this example, it extends to 46.67 years....
What about the costs for maintenance, repair and replacement, or do you seriously consider that your installed A2W will last for at least 26.67 years?
My honest oppinion about the SH scheme: It´s nothing else than a window dressing.