Energy Rating?

baguio

Does anyone know what rating your typical concrete built semi-D that was built in '06 would be likely to come in at?
C or D??

muffler

Im not being flippant here but you may as well ask which insurance group (category) does your average 06 car fall into. Without details there is no way of knowing and in any event your own architect should be in a better position to answer that.

Mellor

baguio wrote:

Does anyone know what rating your typical concrete built semi-D that was built in '06 would be likely to come in at?
C or D??

Half could be C,
Half could be D,
depends on a huge number of factors. Ask the designer, or get a rating done.

baguio

Will do. Thanks.

ardara1

The big factors will be your window performance and area - if the openins are under 25% of total floor area - thats good.

How were your walls, floors and roof insulated - if they met the ELEMENTAL values of the 05 regs (0.27/0.25/0/16) - thats good.

Look at your boiler - Gas good - oil worse - radiators good - under floor heating not so good.

If you hit the good ones - you'll get a C min. (poss

sundodger5

so is underfloor not energy efficient?

mr.wiggle

HI, I believe that underfloor heating is actually one of the most efficient forms of heating and thus will be an integral part of acheiving an A rating( There are loads of factors to include i know).
Just read about an A-rating development in Mallow, and all have underfloor heating.

W.

ardara1

Its a problem with the methodology in the SAP system in the UK on which DEAP is based.

The calculations are based on the house - not how it's actually used - so it standardises heating patterns and geographical area (If you're on top of the a mountain it's ignored) so the heating pattern is based on typical usage, 2 hours in the morning and five in the evening (I think?) You also have to take account of the responsiveness time of the heating system. I was advised by a building control officer that when I used UFH in a design that my fabric insulation would have to be incrreased to compensate.

Saying that - all these inputs make tiny differences in the result - but ALL the tiny adjustments are needed to be made to improve things to a B - C's easy to achieve (So's a - you'll need LCZ'z to achieve an A

baguio

ardara1 wrote:

you'll need LCZ'z to achieve an A

LCZ's??

ardara1

Low & zero carbon technologies

Do-more

ardara1 wrote:

Low & zero carbon technologies

LZC's not LCZ's!;)

muffler

And to be more precise Low to Zero Carbon (as in buildings)

Do-more

muffler wrote:

And to be more precise Low to Zero Carbon (as in buildings)

Low and Zero Carbon
Low or Zero Carbon
Low to Zero Carbon

You can find all the above being abbreviated as LZC's

British Government White papers on the subject which seem to have brought the term into more widespread usage use the term "Low or Zero carbon energy sources"

ardara1

Do-more wrote:

Low and Zero Carbon
Low or Zero Carbon
Low to Zero Carbon

You can find all the above being abbreviated as LZC's

British Government White papers on the subject which seem to have brought the term into more widespread usage use the term "Low or Zero carbon energy sources"

sorry folks - U can put the mis spelling down to dislexia or 1/2 bottle of red - but LZC'c is low and zero TECHNOLOGIES - from GSHP to Solar - some low some Zero carbon, you'll need them to get an A.

UK what Zero carbon homes by 2016 - but no-one will define it - you know we'll follow n Ireland soon enough! 'Sounds green - sign up to It!

galwaytt

Look at your boiler - Gas good - oil worse - radiators good - under floor heating not so good.

Agree on the gas, but the statement about UFH is completely out of line. Calc's used for floor insul values are based on an unheated floor, with some insulation under. An UFH system floor could be considered a floor-upon-a-floor, and the element you could consider an equivalent to your comment is that sub floor under it, not the heated screed itself (assuming done to correct detail). Besides, ufh floors are usually insulated to a higher standard than conventional floors in the first place........

As for the comment by the building control officer, that too seems misleading - the permeability of the building is not linked to how it's heated - but to air tightness, and that is down to on-site application of a good standard detail..........I was at a BRE air tightness test of a house yesterday, very informative actually.

ardara1

galwaytt wrote:

Agree on the gas, but the statement about UFH is completely out of line.
We are discussing the outcome of the DEAP calc when UFH is used - it does not help the rating - I've out lined the reason - I think this should be raised with the those that wrote the program - I know in the UK UFH manufaturers have asked the BRE to look at it.

Calc's used for floor insul values are based on an unheated floor, with some insulation under. An UFH system floor could be considered a floor-upon-a-floor, and the element you could consider an equivalent to your comment is that sub floor under it, not the heated screed itself (assuming done to correct detail). Besides, ufh floors are usually insulated to a higher standard than conventional floors in the first place........

As for the comment by the building control officer, that too seems misleading - the permeability of the building is not linked to how it's heated -

Air permeability testing is a proxy for checking build quality and good detailing - the better the permeability - the more effective the fabric - the more effective the fabric the less the heating demand - so it does effect how the building is heated - ask the Passive Haus guys.

but to air tightness, and that is down to on-site application of a good standard detail..........I was at a BRE air tightness test of a house yesterday, very informative actually.

I think that the GSHP & UFH suppliers should appraoch SEI and ask them to review how their systems are treated - I have only used the spreadsheet version of DEAP - perhaps the new software will be different.

galwaytt

I've been on to SEI today about that spread sheet version too, and am due a follow up call to them tomorrow - the values I got were at odds with BRE's calculation for the same panel. In fact, the SEI one was overly optimistic (....or conversely, BRE were pessismistic........ymmv, as they say !!

I agree about permeability of the building giving somewhat of an indication of the quality, but all things being equal, the statement by that officer (if it's quoted correctly, above that is) that an ufh heated house vs a radiator house requires special treatment is wrong.

baguio

galwaytt wrote:

I was at a BRE air tightness test of a house yesterday, very informative actually.

Would be interested in seeing this done. Where do they do the tests? Are there anymore scheduled?

galwaytt

They physically test houses, usually for the builder. SEI say that in all developments of 10 houses or less, that all houses should be tested for airtightness, and that in in large developments there should be at least 10 houses, and a minimum of 10% of the development, tested. It costs about Eur1k per house for an airtightness test, btw..........

By this reckoning therefore, there should be tests ongoing all the time on a variety of sites..........maybe worth calling in and asking one??

In the case I observed Monday, it was for pilot houses, as they wanted to see how well the houses were assembled and how efficient the manufacturers std details were. The house on Monday scored 3.3 ach, which is very good.

baguio

Just another query as regards energy rating. If you have a stairwell servicing a couple of apartments, is that internal wall (facing the stairwell) treated as a heat loss wall? Should the outside door be included in the calculations?

Had a look through the DEAP manual but couldn't find a definitive answer on it.

galwaytt

Wouldn't each apartment be treated as a separate occupancy ? so that wall to the common area would be treated as a heat loss wall...........but I'd also presume that there'd be a modification factor to allow for the fact that it's not an external wall.........

baguio

Your right. Have found it referenced on pg. 16.

ardara1

galwaytt wrote:

Wouldn't each apartment be treated as a separate occupancy ? so that wall to the common area would be treated as a heat loss wall...........but I'd also presume that there'd be a modification factor to allow for the fact that it's not an external wall.........

Depends what you're talking about TT - To comply with building regulations, you can take the building as a single unit - under the revised part L 2006 - you've to work out the CO2 for each apartment - BUT you can AVERAGE each apartments CO2, and the max permitted CO2 (MPCDER) out but calculating them all - if the averge for total is less than the Max Permitted for total you'll pass Part L.
HOWEVER - -
Every single unit has to have an ENERGY CERT - so you will have a nice cosy B in the middle of the aparments but the penthouse (Fully glazed goal fish bowl on top) could have a G - but he probably doesn't care as he can afford the enrgy cost and the Range Rover in the drive!

Mellor

Its kind of silimar to the diffferent housing types. Terraced houses (mid terrace, end terrace are the same as semis) will always preform better than semi-Ds, which in turn preform better than detatched.

BadCharlie

Im doing the energy rating course. And most houses built in ireland and the average get a 156mark. Which is a c1 Raiting. Some houses will be better or worse as this is the average.

ardara1

BadCharlie wrote:

Im doing the energy rating course. And most houses built in ireland and the average get a 156mark. Which is a c1 Raiting. Some houses will be better or worse as this is the average.

hia bad charlie - I'm getting the same answer with most houses - next question is - 'How do I get to a B' - have a standard answer yet?

(I'm speaking to a guy in Cork that wants an A1 - a mansion of a house with tonnes of glazing and dormer roof - I told him to buy pixie dust!)

Good luck with the course!

sas

ardara1 wrote:

(I'm speaking to a guy in Cork that wants an A1 - a mansion of a house with tonnes of glazing and dormer roof - I told him to buy pixie dust!)

This raises a point I've a few questions on.

Surely the rating is based on a per square metre measurement? i.e. does it matter how the big the house is?

Does it matter how much glazing you have if it all happens to have a u-value of 0.79 (e.g. triple glazed, low e...)? Is it the case that 0.79 is way too high in comparison to the u-value the wall would have if the window wasn't there?

What will be the most limiting factor in the search for an A1?

Mellor

sas wrote:

This raises a point I've a few questions on.

Surely the rating is based on a per square metre measurement? i.e. does it matter how the big the house is?

Does it matter how much glazing you have if it all happens to have a u-value of 0.79 (e.g. triple glazed, low e...)? Is it the case that 0.79 is way too high in comparison to the u-value the wall would have if the window wasn't there?

What will be the most limiting factor in the search for an A1?

size is relevant, and a larger house could do better easier to get a low rating.
A larger house will have an increased spacing heat load per m2 due to more to heat, a zoned heating system will help
but a reduced water heating and electricty load per m2 due to same water requirement over a larger area, and electricty requirement could only be slightly higher. same appliances, and if they are sensible with lights

obviously carbon emmissions will increase, but the letter grade could reduce.

ardara1

sas wrote:

This raises a point I've a few questions on.

Surely the rating is based on a per square metre measurement? i.e. does it matter how the big the house is?

Does it matter how much glazing you have if it all happens to have a u-value of 0.79 (e.g. triple glazed, low e...)? Is it the case that 0.79 is way too high in comparison to the u-value the wall would have if the window wasn't there?

What will be the most limiting factor in the search for an A1?

It just isn't fair SAS - the SMALLER the property the more difficult it is to pass - I've tried 1 bed apartments with 1 patio door and 1 side window - vrey difficult to pass - then again BIG Cavan house that get a B comfortably - yet the Cavan monster produces a mutipier of CO2.

triple glazing is great - BUT
Also reduces HEAT GAIN - so you need more heating!
Also reduces natural LIGHT - so you need more bulbs!

Your window is also around 8 times colder thasn the rest of the walls - so every extra m2 of window - takes at lot of improvement in other areas to make for it.

If you want an A1 - build a SMALL REGULAR SHAPED WELL insulated box with glazing (But shaded in summer) to the south and use renewables to satisfy a reduced energy demand - or go for a B - wear a jumper and turn down the thermostat and save as much energy.

Mellor

ardara1 wrote:

triple glazing is great - BUT
Also reduces HEAT GAIN - so you need more heating!
Also reduces natural LIGHT - so you need more bulbs!

But, the energy saved from from the windows is still much more than the energy lost due to reduced gains and reduced light.

BadCharlie

ardara1 wrote:

hia bad charlie - I'm getting the same answer with most houses - next question is - 'How do I get to a B' - have a standard answer yet?

(I'm speaking to a guy in Cork that wants an A1 - a mansion of a house with tonnes of glazing and dormer roof - I told him to buy pixie dust!)

Good luck with the course!

Well i think it will be very hard to get an A1 house. Your talking about the house for tomorrow project.

One way of getting an A Rating house is to be in a group heating scheme. In Denmark alot of houses have such a system and so there houses will get very good Ratings.
Here in waterford i know of a project were there is a proposed heating system for about 250 houses, school & some other buildings all tapping into the same heating. These buildings will all do very well when it comes to getting there rating. They wont get an A1 raiting but prob get the A3 ( or abouts ).

As for one off houses your going to have your work cut out to get the A raiting. And the price you will pay to get the A raiting i don't think would be worth it.

BadCharlie

Mellor wrote:

But, the energy saved from from the windows is still much more than the energy lost due to reduced gains and reduced light.

In a irish climate you have more dull days then sunny days. So having lots of glass even Tripple Glazed you will lose more heat then gain.

Naux

BadCharlie wrote:

As for one off houses ........And the price you will pay to get the A raiting i don't think would be worth it.

This is the key point as far as I'm concerned.

Mellor

BadCharlie wrote:

In a irish climate you have more dull days then sunny days. So having lots of glass even Tripple Glazed you will lose more heat then gain.

That was exactly what I said.
Energy saved from triple glazing is more than the energy lost due to gains

The price you pay to get an A won't be made back quickly by savings, but it will add alot of value to your house.

Strategicaly placed "sunpipes" can brighten up the interior no end.

Should then be possible to use smaller windows elsewhere to improve the energy rating.

I have them in my hallway & corridor, it's like having 200w bulbs in there during the day.

ardara1

Deleted User wrote:

Strategicaly placed "sunpipes" can brighten up the interior no end.

Should then be possible to use smaller windows elsewhere to improve the energy rating.

I have them in my hallway & corridor, it's like having 200w bulbs in there during the day.

I wonder what whay they'll be treated in the DEAP calculation - you'll have a window one end - then the full circumference X the length of the pipe should be calculated as a WALL? and a U-value calculated for such? - it would need to be well insulated.

Are the easily retro fitted? - and how much do they cost typically?

ardara1

ardara1 wrote:

I wonder what whay they'll be treated in the DEAP calculation - you'll have a window one end - then the full circumference X the length of the pipe should be calculated as a WALL? and a U-value calculated for such? - it would need to be well insulated.

Are the easily retro fitted? - and how much do they cost typically?

Not sure how to calculate heat loss via the pipe, it's a sealed unit 30cm diameter 3m length - I would imagine that you could treat it as a wall/roof of air, but as it is only a small percentage of the fabric, it wouldn't make a huge "hole" in the insulation.

I have them in the roof, they were fitted during the build, but it's just a case of removing a few slates and fitting a bit like a velux type skylight or flue pipe in the roof.

I bought three for £1300 sterling two years ago, they can be got for less - but, the better ones let in more light! the cheaper ones have flexible foil lined duct, whereas the better ones have rigid mirrored tubes.

Mellor

I would imagine that they should be treated as a break in insulation layer, just like timber joists etc. Thats how i'd calculated them.
Calculate a section of insulation equal to cross section of tube. And change u-value to an esimated value of the tube. It would be a decent enough value i would imagine, its trapped air in trhe tube,

Do the ones you have come with a light fitting in the ceiling end of the tube, to use it as a regular light at nightime

sas

Mellor wrote:

That was exactly what I said.
Energy saved from triple glazing is more than the energy lost due to gains

Mellor are you making the point that tripple glazing means you will get reduced passive solar gains but this is countered by the fact that you will retain alot more of the heat generated inside the building?

Mellor

Mellor wrote:

Do the ones you have come with a light fitting in the ceiling end of the tube, to use it as a regular light at nightime

No, I have wall lights in the hallway, Very pleased with the results - much better than the usual dingy bungalow corridor.

mjffey

Mellor wrote:

That was exactly what I said.
, but it will add alot of value to your house.

So what. If I buy a house I buy it because it has the looks, the atmosphere, not because it has a good rating, but maybe we are thinking different.

Our cottage is 1920-ish and has of course no insolation but thick walls. We have no double glazing, but 6mm toughend glass, what keeps the cold and wind out. Oh and of course there are fireplaces. 4 Chimneys in total.
The new extension will be up to standard, but we won't change anything in the original house.
If we would want to sell it and somebodys doesn't like our house because the old part has a low rating, then just don't buy it. Simple as that.:D

No, for me, the only reason for trying to get a higher rate would be that I think that in future there will come a tax on energy rating. The lower the less you pay, the higher the more you pay.

Increasing the value of the house is not a good enough reason for me.

serotonin_sam

mjffey wrote:

So what. If I buy a house I buy it because it has the looks, the atmosphere, not because it has a good rating, but maybe we are thinking different.

That may be but as time goes on, more and more people will be of a different mind. I would be mindful of the fact that whats just been built in the last few years will most probably be viewed as rubbish due to standards beginning to kick in. And if that is the case, substandard housing will not achieve anywhere near as much in the property market - in which case, you may well consider a good rating important.

The rating is likely to be improved upon as time goes on - and as the bar is raised, so will its importance.

sas

There was an article I read recently (can't remember where, possilbe metro or herald AM) that was talking about the energy cert system thats been in place in Denmark (or possibly holland) for the last 3 years or so. It has been declared a failure because it didn't appear have had any impact on purchasers opinions when buying property, main concerns were location and aesthetics.

I realise that energy concerns are growing now more than ever so you can't draw a fair comparison between that example and Ireland going forward.

However, I'm not convinced it will make that much difference either. I've got my planning permission and have spent large amounts of time looking at my options. Going beyond the current building regs. starts to get very expensive very quickly as has already been said here earlier. I could build to current standards for minimum saving of 30K over higher spec (taking windows, hrv, airtight membranes etc) into account and I haven't been looking to go passive. I don't have a large cash pile so 30K over a 30 year mortgage will become approx. 60K. 60K will buy an awful lot of whatever you like to heat a house.

I am still going to aim for a higher spec, however I've no idea what thats going to be yet!

ardara1

sas wrote:

Going beyond the current building regs. starts to get very expensive very quickly as has already been said here earlier. I could build to current standards for minimum saving of 30K over higher spec (taking windows, hrv, airtight membranes etc) into account and I haven't been looking to go passive. I don't have a large cash pile so 30K over a 30 year mortgage will become approx. 60K. 60K will buy an awful lot of whatever you like to heat a house.

I am still going to aim for a higher spec, however I've no idea what thats going to be yet!

It's NEVER mentioned - but Energy Labelling was introduced by Europe to encourage Energyt Efficiency in EXISTING stock - older, less efficient homes. New one built to the 2002 standards should come in around a C1 (Or scrape a - to bring it up form a B to an A will mean speanding A LOT on technologies that have a limited life (Glazing Boilers etc) so you'll not see a pay back in many cases. The difference in running a C house & against running a B in money terms is nothing (200 Euro perhaps)

There is the Carbon argument tho' an A will produce less CO2 - but in the over all scheme of things you might be better just turning down the thermostat, wearing thermal under wear and selling the plasma - SAving energy is 10% technology and 90% lifestyle.

sas

ardara1 wrote:

There is the Carbon argument tho' an A will produce less CO2 - but in the over all scheme of things you might be better just turning down the thermostat, wearing thermal under wear and selling the plasma - SAving energy is 10% technology and 90% lifestyle.

I definitely will take this point on board. However, the vast majority of people I've come across researching the latest build tech are doing so for the sake of their pockets, not the environment. If it happens to be good for the environment too then thats a plus.

serotonin_sam

Theres a lot that can be done as regards building airtightness & use of proper ventilation systems - without the costs being uneconomical.

ardara1

serotonin_sam wrote:

Theres a lot that can be done as regards building airtightness & use of proper ventilation systems - without the costs being uneconomical.

you're right SS - because the 2002 building regulations look good on paper and SHOULD result in a C/B house - build quality is an unknown quantity - the lack of Buildng Control inspection leaves the gap between design performance and actual very wide. The Gov't should be concentrating on enforcement of regs ensuring that the new technolgies they're funding will meet demands in a house that is ENERGY EFFICIENT in the first place - new techologies have little to do with energy efficiency, but are crucial in cutting CO2.

Air tightness testing which is now mandatory in N Ireland is only a proxy for checking build quality. It'll take years but site practice is gradually improving.

sas

ardara1 wrote:

you're right SS - because the 2002 building regulations look good on paper and SHOULD result in a C/B house -

Air tightness testing which is now mandatory in N Ireland is only a proxy for checking build quality. It'll take years but site practice is gradually improving.

Just for clarification, its in theory possible to get to a B with the current building reg. u-values i.e. 0.27 for external walls?

I've found myself going in search of lower and lower u-values. I am completely aware that airtightness is extremely important but I've been putting it second to u-value. In your opinions, at what point does u-value (say for the walls) become less important. For example, say you could actually achieve 0.25, is this a good target. I'm assuming its easier exceed the u-values for the flootr and roof (pitched roofs aside) so I'm seeing the walls and windows as the most limiting factor.

galwaytt

sas wrote:

Just for clarification, its in theory possible to get to a B with the current building reg. u-values i.e. 0.27 for external walls?

I've found myself going in search of lower and lower u-values. I am completely aware that airtightness is extremely important but I've been putting it second to u-value. In your opinions, at what point does u-value (say for the walls) become less important. For example, say you could actually achieve 0.25, is this a good target. I'm assuming its easier exceed the u-values for the flootr and roof (pitched roofs aside) so I'm seeing the walls and windows as the most limiting factor.

Exactly - highly insulated panel or wall, has, on paper a good u-value. However, if the on-site quality isn't what it should be, the gain from that u-value could be handed away in one go with poor detailing. There is a balance to be struck...........but no, I don't know where that point of diminishing returns, on u-value chasing alone, is either........

ardara1

sas wrote:

Just for clarification, its in theory possible to get to a B with the current building reg. u-values i.e. 0.27 for external walls?

I've found myself going in search of lower and lower u-values. I am completely aware that airtightness is extremely important but I've been putting it second to u-value. In your opinions, at what point does u-value (say for the walls) become less important. For example, say you could actually achieve 0.25, is this a good target. I'm assuming its easier exceed the u-values for the flootr and roof (pitched roofs aside) so I'm seeing the walls and windows as the most limiting factor.

Yes SAS - it is - condnesing boiler half decent heating controls - 50% EE lighting 0.22 in floor - 0.14 in ceiling -

But a lot depends on the size and shape of your house - how glazing it has and how it performs - your FABRIC performance is crucially important

Mellor

sas wrote:

Mellor are you making the point that tripple glazing means you will get reduced passive solar gains but this is countered by the fact that you will retain alot more of the heat generated inside the building?

Thats exactly my point. Extra energy retained is far far higher than lost energy gained.
For what its worth consider the other side, single glazing, with the thinest pane possible will result in the highest solar gains and the highest light passing through. But this is massively outweighted by the fact that they keep in no heat at all.