Cavity wall insulation can't be fitted - ASHP issues...

liviboy

Hi all,

With all this talk of switching off gas boilers and everyone moving to ASHP over the next few decades it has brought me back to my own property.

A couple of years ago we had a survey for CWI, being one of only 2 properties in the street that didn't have it fitted.

Survey all went well and installation was booked.

However, the installers spotted that inside our cavity, there is a bubble-wrap foil (Barratt house built around 1999/2000). This foil meant he was unable to proceed with the installation. When I challenged the fact our house was one of the only ones not done he explained it was to do with not being able to guarantee the integrity of the foil, etc. I don't doubt him (end of the day he didn't get paid for the job...) but not sure what to do now. For anyone interested we're in Scotland.

Our house isn't the warmest...but relatively new double glazing (2012), loft insulation, etc...so I worry a bit about the whole switch to ASHP.

Just wondered if anyone had any similar issues or ideas/thoughts?

Spies

My house built in 1994 is also not going to be suitable for a ASHP, just have to wait for hydrogen boilers to come in whenever that is and stick with gas in the meantime.

Meatballs

Spies said:

My house built in 1994 is also not going to be suitable for a ASHP, just have to wait for hydrogen boilers to come in whenever that is and stick with gas in the meantime.

Hydrogen doesn't make much sense. How is hydrogen created? Electricity (or from natural gas..)

May as well just use direct electrical heating (or an offset electrical heating using a battery or heat store) as it should be cheaper?

Hydrogen makes sense for specific requirements and offsetting renewables, but makes little sense otherwise?

Meatballs

liviboy said:

Hi all,

With all this talk of switching off gas boilers and everyone moving to ASHP over the next few decades it has brought me back to my own property.

A couple of years ago we had a survey for CWI, being one of only 2 properties in the street that didn't have it fitted.

Survey all went well and installation was booked.

However, the installers spotted that inside our cavity, there is a bubble-wrap foil (Barratt house built around 1999/2000). This foil meant he was unable to proceed with the installation. When I challenged the fact our house was one of the only ones not done he explained it was to do with not being able to guarantee the integrity of the foil, etc. I don't doubt him (end of the day he didn't get paid for the job...) but not sure what to do now. For anyone interested we're in Scotland.

Our house isn't the warmest...but relatively new double glazing (2012), loft insulation, etc...so I worry a bit about the whole switch to ASHP.

Just wondered if anyone had any similar issues or ideas/thoughts?

If check with a few more companies. Otherwise insulated plasterboard? 

Spies

Could go with external cladding if you dont want to lose internal space.

Reed_Richards

It's a complete myth that you need a well-insulated house in order to be able to use an ASHP.  That could only ever be true if ASHPs had a limited output capacity but they don't.  However under the current grant scheme (RHI) you cannot get the grant if your EPC recommends adding cavity wall insulation or loft insulation.  So if you were to have an EPC assessment you might need to show the EPC assessor that cavity wall insulation is not recommended for your house.

Exiled_Tyke

Reed_Richards said:

It's a complete myth that you need a well-insulated house in order to be able to use an ASHP.  That could only ever be true if ASHPs had a limited output capacity but they don't.  However under the current grant scheme (RHI) you cannot get the grant if your EPC recommends adding cavity wall insulation or loft insulation.  So if you were to have an EPC assessment you might need to show the EPC assessor that cavity wall insulation is not recommended for your house.

Surely the point is not that an ASHP won't work but in the vast majority of cases it doesn't make sense to go down this route if the house doesn't have decent insulation.  It will be cheaper and save more money/energy to upgrade the insulation before going down the ASHP route?  

And as for the EPC certificates.....  Well the one I got for my current house was terrific in terms of it qualifying me for PV FIT payments but in other respects was meaningless and full of assumptions (such as assuming cavity wall insulation without any evidence to support the claim).

Verdigris

Yes, EPCs aren't worth the pixels they're painted with. Any EPC I look up for a property I know can have huge draughty holes picked in it. Not that I'm complaining; the gaff I'm presently buying can easily be converted from a F to an A.

Exiled_Tyke

And in answer to the original question asking for thoughts. Well I am gradually adding insulation to the external walls on the inside and also under the floors.  When I started on this project I didn't expect it to pay for itself but now I'm not so sure with what is currently happening to energy prices.  

Reed_Richards

Exiled_Tyke said:
Surely the point is not that an ASHP won't work but in the vast majority of cases it doesn't make sense to go down this route if the house doesn't have decent insulation.  It will be cheaper and save more money/energy to upgrade the insulation before going down the ASHP route?  

An ASHP will work perfectly well in a badly-insulated house but you'll need a one with a larger output capacity.  Unlike boilers where upping the output adds little to the price, the cost of an ASHP increases quite significantly with its output capacity.  That's why upgrading the insulation first is such a good thing to do.      

liviboy

Thanks everyone for your comments.

To answer a few points, the company that refused to fit the CWI is locally "the company" so when others see on the system (I believe run by the local council) that it was refused by them the others don't even bother coming out to have a look.

External insulation aint happening. I live in an estate and our houses are all brick-fronted. If I lived in a rendered house then perhaps but I just wouldn't like my house looking so vastly different to the others on the street...plus I bought the house specifically because it was brick-facing as opposed to rendered/clad/etc.

Hydrogen I've been told isn't "the solution".

Insulated plasterboard could work but the cost and mess involved will be huge so it'll need to be something done perhaps over a longer period of time.

Thanks everyone for your thoughts.