Buying house - planning BER upgrades

[IronMike247]

Hi,
As the title suggests, I am currently in the process of buying a house, and I am hoping to do a few upgrades once we have moved in. Primarily, we are hoping to improve the BER rating to a B3 or better to avail or green mortgage rates, but also hoping to reduce energy bills. The house would need to be upgraded to B3 within 6 months of drawing down the mortgage in order to avail of this rate.

I have a few questions around the upgrades in general.

Currently the house is at the lower limit of C2 (197 kwh/m2/year). The BER assessment was done in September of last year. The house is a 2 story, 4 bedroom detached of appox 188m2.
The advisory report lists a few recommendations to increase efficiency:

The roof insulation seems to be the main starting point to me. The engineer provided photos of the attic which appear to show a quite thin layer of polystyrene insulation, which I assume is not doing much.

The house is heated by an oil boiler. This is a Firebird Popular 120. I am not sure on the number of radiators in the house, but I can check on this later.
Is there scope for upgrade potential with the boiler? I understand that a condensing boiler may be more efficient than this one, but is this an improvement worthy of the upfront investment?
To go along with that, I understand there is an SEAI grant available for upgrade of heating controls. Would smart heating controls be compatible with this boiler?

As I understand, there is potentially scope for a large improvement in BER rating by adding in a solar system. I am not too sure on the details of how many panels I would require, whether to get a battery etc.

Would it be possible for me to achieve a B3 with this house by adding in the roof insulation, adding heating controls, and adding a solar system?
Is there a way I can calculate the potential upgrade values?

Finally, I understand that in order to get the SEAI grants for the upgrades, I need to get the BER re-assessed. Does this have to be done for each individual upgrade, or can one "catch all" BER assessment be done after all upgrades are complete? I will not be going for the SEAI one stop shop.

 

[RobinMx]

Would it be possible for me to achieve a B3 with this house by adding in the roof insulation, adding heating controls, and adding a solar system?
Is there a way I can calculate the potential upgrade values?

Finally, I understand that in order to get the SEAI grants for the upgrades, I need to get the BER re-assessed. Does this have to be done for each individual upgrade, or can one "catch all" BER assessment be done after all upgrades are complete? I will not be going for the SEAI one stop shop.

Last year, I upgraded the attic insulation, replaced a 20 year old boiler and installed a small solar system (4kW, no battery) and the BER rating jumped from C1 to A2. I don't really understand how the calculation works though. But I can answer your second question: I did a single "catch-all" BER assessment at the end to find out the new rating and get the two SEAI grants for solar and insulation. Just make sure to get the BER cost deducted if you go with a solar installer that normally handles everything, and you can send it to them once you have it done.

The main concern I'd have with your timeline is finding people to do the work... The solar installers I contacted last year were all extremely busy, with appointments several months later.

 

[FANTANA]

Hi,
As the title suggests, I am currently in the process of buying a house, and I am hoping to do a few upgrades once we have moved in. Primarily, we are hoping to improve the BER rating to a B3 or better to avail or green mortgage rates, but also hoping to reduce energy bills. The house would need to be upgraded to B3 within 6 months of drawing down the mortgage in order to avail of this rate.

I have a few questions around the upgrades in general.

Currently the house is at the lower limit of C2 (197 kwh/m2/year). The BER assessment was done in September of last year. The house is a 2 story, 4 bedroom detached of appox 188m2.
The advisory report lists a few recommendations to increase efficiency:
View attachment 8719
The roof insulation seems to be the main starting point to me. The engineer provided photos of the attic which appear to show a quite thin layer of polystyrene insulation, which I assume is not doing much.

The house is heated by an oil boiler. This is a Firebird Popular 120. I am not sure on the number of radiators in the house, but I can check on this later.
Is there scope for upgrade potential with the boiler? I understand that a condensing boiler may be more efficient than this one, but is this an improvement worthy of the upfront investment?
To go along with that, I understand there is an SEAI grant available for upgrade of heating controls. Would smart heating controls be compatible with this boiler?

As I understand, there is potentially scope for a large improvement in BER rating by adding in a solar system. I am not too sure on the details of how many panels I would require, whether to get a battery etc.

Would it be possible for me to achieve a B3 with this house by adding in the roof insulation, adding heating controls, and adding a solar system?
Is there a way I can calculate the potential upgrade values?

Finally, I understand that in order to get the SEAI grants for the upgrades, I need to get the BER re-assessed. Does this have to be done for each individual upgrade, or can one "catch all" BER assessment be done after all upgrades are complete? I will not be going for the SEAI one stop shop.

Yes roof have come in very poor, is it a dormer? Polystyrene would be typical of dormer roofs. Would recommend putting 300mm of rockwool type insulation down if it is a normal attic (one roll
200mm and one roll 100mm on top of each other). If it is a dormer you need to use a breathable insulation or rigid boards. If you are anyway handy the rockwool type job is easy enough to DIY.

That boiler is non condensing, I would replace it with a condensing boiler. It may already have controls, upstairs, downstairs and HW. At the same time as doing the boiler the hot water tank should be upgraded to a factory insulated one if it isn’t already.

Solar will drag up the BER considerably, remember though this upgrade will in no way improve the comfort of the home.

Why do you have six months only to upgrade? Could you not drawdown on a variable rate and then fix a green loan when you have the new BER?

 

[Pinoy adventure]

Smart heating controls would be compatible with the new models of oil boilers.
A new oil boiler alone would bring up the rating but if it’s an old heating system why not upgrade the lot ??
(Let’s imagine the system is old and corroded,you would be running it through the new boiler even with a mag filter fitted).

 

[IronMike247]

Yes roof have come in very poor, is it a dormer? Polystyrene would be typical of dormer roofs. Would recommend putting 300mm of rockwool type insulation down if it is a normal attic (one roll
200mm and one roll 100mm on top of each other). If it is a dormer you need to use a breathable insulation or rigid boards. If you are anyway handy the rockwool type job is easy enough to DIY.

That boiler is non condensing, I would replace it with a condensing boiler. It may already have controls, upstairs, downstairs and HW. At the same time as doing the boiler the hot water tank should be upgraded to a factory insulated one if it isn’t already.

Solar will drag up the BER considerably, remember though this upgrade will in no way improve the comfort of the home.

Why do you have six months only to upgrade? Could you not drawdown on a variable rate and then fix a green loan when you have the new BER?

Thanks for info.
Yes sorry, I think it comes under the definition of a "wall dormer".
This is the insulation that is there at present:

There doesn't appear to be any insulation on the "floor" of the attic:

Would rigid boards be required in this scenario? And if doing DIY, would this still be sufficient to avail of the grant?

I am not certain on what controls are there for the boiler at present, but I think it may be a basic on/off/timer for heating or hot water.
I believe a solar system would be the most cost effective way to get the BER raised quickly to a B3, based on the above recommendations?

Regarding the mortgage interest rate, I suppose we hadn't considered going with a variable rate initially and fixing once the upgrades are completed.
Lots of food for thought, thanks for info.

 

[IronMike247]

Last year, I upgraded the attic insulation, replaced a 20 year old boiler and installed a small solar system (4kW, no battery) and the BER rating jumped from C1 to A2. I don't really understand how the calculation works though. But I can answer your second question: I did a single "catch-all" BER assessment at the end to find out the new rating and get the two SEAI grants for solar and insulation. Just make sure to get the BER cost deducted if you go with a solar installer that normally handles everything, and you can send it to them once you have it done.

The main concern I'd have with your timeline is finding people to do the work... The solar installers I contacted last year were all extremely busy, with appointments several months later.

Thanks for the info. Good to know that one BER is sufficient for all upgrades.
The timeline is a concern alright, I am trying to get ahead of it by researching and deciding exactly what our upgrade plan is now, before we move in. I would like to have some quotes lined up before we draw down but this may not be possible.

 

[David_Dublin]

The house would need to be upgraded to B3 within 6 months of drawing down the mortgage in order to avail of this rate.

Who is setting this deadline? Is it a fixed term mortgage? If so, are they giving you the preferential rate on trust and revoking it after 6 months. If not fixed, then surely when you can avail of the rate when your BER improves?

 

[IronMike247]

Who is setting this deadline? Is it a fixed term mortgage? If so, are they giving you the preferential rate on trust and revoking it after 6 months. If not fixed, then surely when you can avail of the rate when your BER improves?

Yes it is a 30 year mortgage with the first 4 years fixed @ 3.95% from BOI.
I believe the "green" rate of 3.65% is only available when first drawing down the mortgage, or when switching from another lender (as per BOI website)
We were advised by our broker that if we can improve the property to a B3 or better within 6 months of drawing down, we can switch to the lower green rate.

Does this sound correct?

 

[Micks'r]

@IronMike247, are you looking to improve the BER rating for improved mortgage rate purposes OR have a more comfortable home and lower energy bills? The reason for asking is that from the pics you posted these two things do NOT appear to be mutually inclusive.

 

[IronMike247]

@Micks'r Ideally we are looking to do both. Better insulation leading to a more efficient and comfortable home, leading to a better BER rating, leading to a better mortgage rate.
What do you mean by not mutually inclusive based on the photos? My understanding is that the insulation currently there is quite poor, is that correct?

 

[Micks'r]

@Micks'r Ideally we are looking to do both. Better insulation leading to a more efficient and comfortable home, leading to a better BER rating, leading to a better mortgage rate.
What do you mean by not mutually inclusive based on the photos? My understanding is that the insulation currently there is quite poor, is that correct?

There is too little info to go on but basically I'm not quite sure where the thermal envelope* is wrt the roof. I see insulation on the slope between the rafters and nothing between the joists on the flat. This suggests to me that the thermal envelope is running up the rafters to the ridge, yet I'm not convinced that the air tight barrier (if present at all) is along this line and am presuming that the roof timbers (rafters) are (need to be) well ventilated. If I'm correct, then the insulation that is there is actually doing very little if any actual insulating (slowing the conductive heat flow) because the heat is escaping by convection before the insulation has a chance to do anything. The BER (on the other hand) may well include the insulation as effective ON PAPER.
That's why I mentioned 'not mutual inclusive'.

*Thermal envelope is made up of BOTH the insulation layer AND the air tight barrier

 

[AJAM]

With no roof insulation in the way (on the flat) it would be easy to do a good DIY air sealing of that attic with some expanding foam and some silicon or acrylic sealer. Then add 300- 400 mm of wool insulation on top. This will make an enormous difference.

There are some great videos on YouTube showing how to air seal an attic

Air Sealing and Insulating a Conventional Attic

http://www.drenergysaver.com | 1-866-607-0191The energy conservation experts at Dr. Energy Saver first look into the attic when helping improve a home's ener...

www.youtube.com

 

[AJAM]

That boiler is non condensing, I would replace it with a condensing boiler. It may already have controls, upstairs, downstairs and HW. At the same time as doing the boiler the hot water tank should be upgraded to a factory insulated one if it isn’t already.

A new oil boiler alone would bring up the rating but if it’s an old heating system why not upgrade the lot ??
(Let’s imagine the system is old and corroded, you would be running it through the new boiler even with a mag filter fitted)

A new condensing boiler will definitely bring up your rating. It will also pay for itself over time. i.e. if your going from 60% efficient to 90% efficient on a 2000 euro annual oil bill you might save roughly 500 per year.

But if you are going to upgrade the whole thing (pipes, hot water cylinder and radiators), then you might as well get a Heat Pump. With the 6,500 euro Heat Pump grant it will likely work out cheaper for you (or worst case roughly the same) to install, but you'll have significantly lower running costs.

The only issue would be getting it done in 6 months. But if you upgrade the roof insulation and the solar panels, you would likely hit the BER B3 before having to upgrade the heating.

 

[David_Dublin]

Careful of heatpumps on a renovation. Unless you're close to passive house level airtightness, you could have very high electricity bills.

 

[IronMike247]

There is too little info to go on but basically I'm not quite sure where the thermal envelope* is wrt the roof. I see insulation on the slope between the rafters and nothing between the joists on the flat. This suggests to me that the thermal envelope is running up the rafters to the ridge, yet I'm not convinced that the air tight barrier (if present at all) is along this line and am presuming that the roof timbers (rafters) are (need to be) well ventilated. If I'm correct, then the insulation that is there is actually doing very little if any actual insulating (slowing the conductive heat flow) because the heat is escaping by convection before the insulation has a chance to do anything. The BER (on the other hand) may well include the insulation as effective ON PAPER.
That's why I mentioned 'not mutual inclusive'.

*Thermal envelope is made up of BOTH the insulation layer AND the air tight barrier

Thanks for the detailed info.
Am I correct then in thinking that there should be insulation between the joists, as there is nothing there at the moment? Should the insulation that is there between the rafters be replaced also?
The attic insulation was one of the main things the engineer recommended to be upgraded, so I will be looking to do this regardless of whether I go ahead with getting the BER redone etc.

 

[Micks'r]

Thanks for the detailed info.
Am I correct then in thinking that there should be insulation between the joists, as there is nothing there at the moment? Should the insulation that is there between the rafters be replaced also?
The attic insulation was one of the main things the engineer recommended to be upgraded, so I will be looking to do this regardless of whether I go ahead with getting the BER redone etc.

From this remove I can't answer that. As said earlier, the thermal envelope needs to be defined and then insulated and air tightened accordingly. This definition is key. Whoever does it needs to be well versed in actual heat loss mechanisms and not just a box ticking BER monkey assessor. Perhaps, get back in contact with the engineer and get his/her input.

 

[AJAM]

Am I correct then in thinking that there should be insulation between the joists, as there is nothing there at the moment? Should the insulation that is there between the rafters be replaced also?

Yes you are correct. And the reason is simple, because above the joists is not livable space that you want to heat. You want to keep all that expensive heat below the joists, where you can enjoy it.

There is a possibility that the "Thermal Envelope" was designed to be above the joists, but you can address this by air sealing the attic first.

Also phone your BER assessor and ask them. They should be able to tell you where the thermal envelope sits. And they should be able to confirm that the best place for the insulation is between the joists.

 

[AJAM]

Careful of heatpumps on a renovation. Unless you're close to passive house level airtightness, you could have very high electricity bills.

This is just fossil fuel FUD spread by the daily telegraph.

A properly designed heat pump system will be cheaper to run than oil, or gas.

Also the OP's Heat Loss HLI (2.408) is only slightly above the acceptable limit for the heat pump grant (2 or 2.3 with limits). A few upgrades and the HLI will sit well inside the grant limit.

 

[David_Dublin]

This is just fossil fuel FUD spread by the daily telegraph.

A properly designed heat pump system will be cheaper to run than oil, or gas.

Also the OP's Heat Loss HLI (2.408) is only slightly above the acceptable limit for the heat pump grant (2 or 2.3 with limits). A few upgrades and the HLI will sit well inside the grant limit.

LOL. I don't read the Daily Telegraph. And the HLI isn't something I would be basing anything on, certainly not a singificant investment - it's a number a computer program comes up with, it doesn't take into account how well, or poorly, a house is constructed. Why not get actual data from a pressure test to ascertain how draughty or airtight your house is. There are a lot of people out there with A rated houses with high costs of running heat pumps, it's not just FUD.

 

[AJAM]

You're confusing 2 different things.
That a leaky, poorly insulated house will cost a lot to heat. Obviously this is true whether its heated by a heat pump or by fossil fuels.
That it will cost more to heat using a heat pump, comes entirely down to how efficient the heat pump (or more accurately the system design is).
If the heat pump is more than 260% efficient then it will be cheaper to run than gas and far cheaper than oil.
If designed correctly a modern heat pump should be able to achieve efficiencies of 300 or 400%.

Of course if you are living in a drafty uninsulated house, it makes more sense to first air seal and insulate, rather than upgrading your heating system. But this is true no matter what heat source you use.

And the HLI isn't something I would be basing anything on,

Well the grant is based on the HLI, so if you want 6,500 euro towards the cost, you need to hit their number, because they aren't going to accept a pressure test.