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Typical BER improvement after solar pv install



  • Registered Users Posts: 775 ✭✭✭cobham

    We had BER done in 2012 in order to get grant for gas boiler/attic insulation upgrade. We got a C3 then. Since then the only extra work to solar installation was small bit of external wall dry lined. We now have a C2. I had hoped for bit better. Our solar is a 16 panel (7.36kw) system. The inspector warned that the parameters have changed for doing the certification over past 10 yrs so I should not compare the earlier one.

  • Registered Users Posts: 8,497 ✭✭✭micks_address

    yeah our previous ber's were done in 2018 and updated in 2020... and again in january this year..

  • Moderators, Social & Fun Moderators Posts: 15,058 Mod ✭✭✭✭AndyBoBandy

    When I bought in 2014 the house was a C3, and since owning the house we replaced the open gas fire with an inset stove, replaced a wooden front door with a composite door, had the attic converted (including the extra insulation that goes with it), installed a Nest Thermostat, installed LED light bulbs all over the house (the assessor didn’t believe me until I whipped out the app and showed him all the lights were Philips Hue Smart LED bulbs)….

    then the solar install included a 5.78kWp system and 5kWh battery, and it brought the BER down to a B3 (in Feb 2022). we were just shy of being a B2, which I think we would/should have got if the guy took it a bit more seriously…. But in the end I got what I needed and the Solar installer received the grant payment….

  • Registered Users Posts: 8,497 ✭✭✭micks_address

    our journey sounds simillar but we ended up at a2 from c3.. semi detached 1980s house.. inset stove as well.

  • Registered Users Posts: 1,727 ✭✭✭tnegun

    4.2kwp of panel with a 3.6kw inverter and we went from a C3 to B1 just shy of the A3. I added extra loft insulation and to my surprise covering the alleyway along one side of the house helped improve the score too!

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  • Registered Users Posts: 775 ✭✭✭cobham

    I quizzed the BER chap and he said would be best to deal with wall insulation ( detached house so lot of external walls) and to upgrade windows to modern double glazing, our presence double glazed wooden windows do not rate apparently.

  • Registered Users Posts: 8,497 ✭✭✭micks_address

    Yeah the report should outline what you can do to improve the ber.. for ours we could get a1 if we replaced the relatively older double glazing and pvc doors but that's a big cost for a slight move up in the scale

  • Registered Users Posts: 1,419 ✭✭✭DC999

    Afaik the criteria to hit a certain BER level after the solar install is gone. You just need to submit the new BER. Might have been there in early 2022 when you got yours. Tbh, our 1940s gaff would need 10000s to get to a B - would be a deep retro fit job.

  • Moderators, Social & Fun Moderators Posts: 15,058 Mod ✭✭✭✭AndyBoBandy

    Yeah, I knew the requirement was to end up no lower than a C3 and given we were already C3 I knew it wouldn’t be an issue.

  • Registered Users Posts: 775 ✭✭✭cobham

    The BER is valid for 10 yrs so one less thing to get done if thinking of selling or renting in that time period.

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  • Registered Users Posts: 25 ian123

    Why does adding solar PV impact on BER ? Ive read that "A BER does not include electricity used for purposes other than heating, lighting, pumps and fans" - so if i have gas heating and run led bulbs everywhere, why should a 4 or 8kW solar PV install that will feed the main domestic appliances change a BER by as much as folks have stated? The power consumption of those devices is NOT factored in any BER calculation.

    Also should the BER kWh/m2/year * sqM of a house be close to the total Electricty and Gas usage for a year ( or just what is used to heat and light the house eg Gas kWh + some kWh amount for lights)?

    Ie a BER of (B2) 112kWh/m2/Yr * 214sqm = 23,968 kWh (heat and lights) - so if a gas bill was showing 16,000kWh - should that be a BER of 16,000 kWh/214m2 = 74 kWh/m2/Yr or an A3 rating?

    If the gas bill was just 12,000 kWh, then that is ~56kWh/m2/Yr

  • Moderators, Home & Garden Moderators Posts: 5,902 Mod ✭✭✭✭graememk

  • Subscribers Posts: 41,215 ✭✭✭✭sydthebeat

    First point, the BER system is based on lots of averages and assumptions, so there is absolutely no correlation between the actual energy used in a house versus the BER. Over large numbers it would even out, but to think it's correct for every specific application is wrong.

    Secondly, the reason PV has such an impact on the BER, even if it's a gas / oil heated house, is because the electricity used for the other elements (lighting, pumps, fans, water heating etc) comes from a grid that is inefficient ( but getting better).

    Up to Feb this year there needed to be more than 2kwhr of power put into the grid system to produce 1kwh of electricity. Since Feb that's down to 1.75.

    Therefore, up to Feb, every kwhr that your pv supplied to your house, you got an uplift of over 2kwhrs when assessing you BER.

    of course, for houses which have a bigger electricity use ie heat pumps / direct or storage heating etc, the uplift will be much bigger

  • Registered Users Posts: 137 ✭✭alexf1

    Our house (built in 2018) was an A3 with 1kWp of pv panels installed by the builder. I replaced those with 6.4kwp of pv panels and my BER went to an A1. Happy enough with that..

    The exact same houses are still being built in the estate by the same builder and yet by regulation all of these need to be A2 minimum. Not sure what they did to improve the ratings but none of the new houses have loads of solar panels, usually just 4 like my house had.... I still wonder why our planning system doesn't demand that more houses are designed and built to face the sun and have uninterrupted south facing roof space for pv panels.

  • Moderators, Sports Moderators Posts: 18,800 Mod ✭✭✭✭slave1

    BER calculation criteria is constantly updated, what was a A3 in 2018 could be a A2 now (but I would have thought the other way around)

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  • Registered Users Posts: 2,384 ✭✭✭1874

    After fitting Solar PV, 8.3kwp, Im trying to locate the previous BER assessor (moved to house last year) as I get the impression that one BER assesor to the next may get a different result, so dont want to increase BER from a different lower level if assessed by someone other than the assessor engaged by the sellers, Also, if they have the pre sale BER work done, then I can point out the additional other aspects done for improvement aside from solar PV (LEDs and some pipe insulation upgrades), given the work was done recently, I'm hoping they can modify for the improvements and it may be cheaper to get done also.

    While I can see the assessor no. & the assessor company no. on the pre sale BER and advisory report which I got from Seai website using the MPRN,but when I search assessors, that information isn't part of the details of available persons/businesses. I suspect the Seai wont give me the name of the assessor or business who completed the original pre sale BER, I could try explain but I'd if I can locate the assessor myself I'd prefer that option.

  • Registered Users Posts: 150 ✭✭Dev1234

    I recently got a post-solar install BER completed and the assessor said that he could get access to the detailed report of the original BER assessment if needed so you should at least be able to get that data.

    My understanding is that the how the BER is calculated has changed over time. Not sure if that means that a B3 rating from say 8 years ago would now be a B2, if it would drop to a C1 or stay the same but from reading on here the process has changed.

  • Registered Users Posts: 775 ✭✭✭cobham

    Yes I was told different parameters now. Also a BER is only valid for 10 yrs... I am bit disappointed that the solar only moved us up one level.

  • Moderators, Home & Garden Moderators Posts: 5,902 Mod ✭✭✭✭graememk

    Unless your actively selling/looking for a "green" mortgage, don't worry about the ber.

  • Registered Users Posts: 775 ✭✭✭cobham

    Agree Graeme but still it will have to 'do' for next 10 yrs....might see me out 😏

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