BER Technical thread

mcm09 · 21-01-2009 9:12pm

Link to one and a half story house drawing - http://www.hvva.org/hvvanews7-5m.JPG
(just to give a picture of what I am on about!)

I haven’t come across this out in the field but my own house is a one and a half story. While the room in roof option for existing dwellings it doesn’t apply to half stories. Here is how I approached it when practicing on my own house.

The external walls come up about 1 meter before the roof takes over. I include this in my wall measurements and get average ceiling height for the dimensions tab. What I am wondering about is the roof. Here is my proposed solution -

I put 2 entries for roof.

One for the area above the horizontal ceiling where you have some attic over it. i.e. the highest point of the ceiling before it starts to slope down to the external walls. This part was straight forward, I treated it like any other roof. Got the area, measured the insulation and selected insulated at joist level in DEAP.

The other roof entry is for the part that slopes up from the external walls. There are 2 areas like this one to the back and one to the front of the house.
I got the area of both and added them together for one entry.
Removed the area of the 2 velux windows to the back
Removed the opening for the dormer window to the front. This actually sits in to the wall so I removed the appropriate portion of the area from the roof and the balance from my external wall measurements.
Got the area of the roof over the dormer window and added this to my main area.
I then entered this roof area in DEAP as insulated at rafter level – insulation unknown.
I ignored the small wall areas to the side of the dormer window – I assumed this would be okay given the loose way DEAP allows you calculate the room in roof.

What do you guys make of this procedure? I hadn’t been shown a method of doing this in training so I logical it out as best I could. Any comments, criticism or advice more than welcome.

Thanks in advance

sydthebeat · 21-01-2009 9:14pm

its very hard to read that... can you edit it please??

lottyprop · 22-01-2009 12:33pm

Hi mcm09,

I couldn't fault your logic there anyway.

Regarding the external walls on the dormer, you could possibly get the area here and enter as timber frame walls to be a little more accurate.

lotty

dahayeser · 22-01-2009 2:37pm

Hi guys, up until now I have only assessed one property built pre 1990. That was a 1960's mid terraced property with some upgrades and it came out as a D rating.

Yesterday I assessed a 3 bed semi 101 sq m with a small extension. The main house built in 1954 (94 sq m) and the extension 7 sq m built in 1973.

A few quick details ..
The wall area 80 and 20 sq m for house and extension respectively, assumed 300mm cavity. Total exposed perimeter of 29.5

The good / ok

Pvc double glazed windows and doors 16mm air filled
75mm attic insulation
30mm cylinder jacket on 110 litre cylinder
living room 15.5% of total

The bad

Timer clock but no other heating controls
15% low energy lighting
Primary pipe work uninsulated & no cylinder stat
68% efficient gas boiler adjusted to 64.6%
Thermal mass medium-high .. based on -

40% of GF solid 60% suspended - medium
Solid external walls - heavy
Solid seperating walls - heavy
90% of internal walls also solid - heavy

The ugly

3 chimneys & 3 vents
Secondry heating sys was a 20% efficient open gas fire
60% of ground floor is suspended

I was expecting an E2 or at worst an F but it came out as a "G".

I would have expected that the dreaded "G" would be reserved for electric heating, single gased windows, no attic insulation, detached, early 1900's etc ??

Does this sound odd to those of you with more experience ? I have been meticilious with my survery and calculations?

Any thoughts much appreciated.

sydthebeat · 22-01-2009 3:02pm

can i ask why you assumed 300mm cavity?

dahayeser · 22-01-2009 3:56pm

The kitchen is partially in the main house and partially in the extension. I measured the arch between the two (the old external wall) and it was just a couple of mm's over 300mm.

I will probably end up defaulting to stone. I am going to check with SEI if this would be sufficient as most houses built in the 50's would have been cavity walls.

topcatcbr · 22-01-2009 5:44pm

dahayeser wrote: »

Hi guys, up until now I have only assessed one property built pre 1990. That was a 1960's mid terraced property with some upgrades and it came out as a D rating.

Yesterday I assessed a 3 bed semi 101 sq m with a small extension. The main house built in 1954 (94 sq m) and the extension 7 sq m built in 1973.

A few quick details ..
The wall area 80 and 20 sq m for house and extension respectively, assumed 300mm cavity. Total exposed perimeter of 29.5

The good / ok
Pvc double glazed windows and doors 16mm air filled
75mm attic insulation
30mm cylinder jacket on 110 litre cylinder
living room 15.5% of total

The bad

Timer clock but no other heating controls
15% low energy lighting
Primary pipe work uninsulated & no cylinder stat
68% efficient gas boiler adjusted to 64.6%
Thermal mass medium-high .. based on -
40% of GF solid 60% suspended - medium

Solid external walls - heavy

Solid seperating walls - heavy

90% of internal walls also solid - heavy

The ugly

3 chimneys & 3 vents
Secondry heating sys was a 20% efficient open gas fire
60% of ground floor is suspended

I was expecting an E2 or at worst an F but it came out as a "G".

I would have expected that the dreaded "G" would be reserved for electric heating, single gased windows, no attic insulation, detached, early 1900's etc ??

Does this sound odd to those of you with more experience ? I have been meticilious with my survery and calculations?

Any thoughts much appreciated.

This seems right to me
Firstly the default for that age will assume no insulation in walls.
The boiler has a very poor performance.
So a G seems fair.

If you change the boiler (90%) and insulate the walls you should come up to a D Then do the ceiling and hey presto you should be up to a C.

Now that will be €1:D:D

sinnerboy · 22-01-2009 6:15pm

See what 300mm attic insulation
75 cylinder insulation ( jacket over jacket )
75% LEL's gets you

Do you want any cigarettes or milk with that :rolleyes:

( that comment is not at query here - picking up on "Tesco" gag in the BER Cost thread )

.

dahayeser · 23-01-2009 10:39am

Cheers men. PM me your address topcatcbr and there will be €1 and 2 smiley faces winging their way to you in todays post!

I'd done the calculations alright - changed the boiler, stuck in a flueless gas fire, increased attic insulation etc I was just amazed thatthis house scored so badly give that there are so many tiers possible below this..

I it seems wrong that this house is graded the same as a house built 75 years earlier,has no attic insulation, poor condition single glazed windows and doors, electric storage heating.

We have almost 3 times as many grades in our BER scale compared with the UK based on this I would be inclined to think that it may be a bit too technical at the the top level or the scale and a way too general at the lower end.

sydthebeat · 23-01-2009 11:48am

dahayeser wrote: »

Cheers men. PM me your address topcatcbr and there will be €1 and 2 smiley faces winging their way to you in todays post!

I'd done the calculations alright - changed the boiler, stuck in a flueless gas fire, increased attic insulation etc I was just amazed thatthis house scored so badly give that there are so many tiers possible below this..

I it seems wrong that this house is graded the same as a house built 75 years earlier,has no attic insulation, poor condition single glazed windows and doors, electric storage heating.

We have almost 3 times as many grades in our BER scale compared with the UK based on this I would be inclined to think that it may be a bit too technical at the the top level or the scale and a way too general at the lower end.

i wouldnt agree, I do not think there are enough grades at the top end.

The vast majority of BERs on new dwellings are in the B3 catagory, which basically means compliance with min regs. Its extremly difficult to climb the B grade to an A3.....

nouveau_4.0 · 23-01-2009 12:53pm

Where can the layman find information about BER ratings?

My house was recently rated C1. How does this compare to the norm, what does it mean? Can I try to improve it? Is it possible to get it reassessed afterwards? Ect.

Any links to a good site with this type of info?

dahayeser · 23-01-2009 12:59pm

Fair point on going froma B to an A3. I'm probably not in a position to comment on the higher end of the scale. The highest rating I have issued so far has been a C1.

I do however think there should be a distinction made between the house I have outlined above and a property that is significantly worse. I have seen houses with old timber windows that a bird could fly in and that's when they are closed.

Having the property I am discussing throw into the same category as a property with windows like these combined with zero insulation and very inefficient heating (i.e. electric ) does not seem right.

I realise any system will have its limitations but the lower end of the scale seems far too general to me.

mcm09 · 23-01-2009 1:11pm

nouveau,

Your BER assessor should have provided you with an advisory report with your rating. Did you get one ?

You should also be able to contact your assessor and get advice on how much each change or combination of changes will impact your rating.

If you were getting your house reassessed assuming there aren't any major structural changes the same assessor should reassess for a nominal fee.

topcatcbr · 23-01-2009 5:38pm

nouveau_4.0 wrote: »

Where can the layman find information about BER ratings?

My house was recently rated C1. How does this compare to the norm, what does it mean? Can I try to improve it? Is it possible to get it reassessed afterwards? Ect.

Any links to a good site with this type of info?

A C1 is quite a good rating for a property rated from a survey. I have done quite a few I would consider a C1 a Good result.

You can improve it and your assessor should be able to let you know how.

This is where the real skill comes in though and will show the professional from the chancer.

They probably wont do this for free but it shouldnt cost too much.

brianmacl · 24-01-2009 1:32pm

topcatcbr wrote: »

My understanding of this is a system which cannot provide hot water only has an emersion as secondry hw heating. That means primary heating by means of an open fire or stove with backboiler will have an emmersion shown. all other systems will not. The point made to me when i asked this was with all other systems the rads can be turned off by the valves which would mean the boiler was then capable of providing hot water only wthout providing backround heat in the summer. backboilers are not capable of this.

There does not need to be any zoning or sofisticated boiler controls or even an isolating valve.

This is something I raised with the trainer in the BER course and was told that unless there were zone or sofisticated boiler controls then one had to assume that secondary heating was used during the summer.

sydthebeat · 24-01-2009 3:18pm

brianmacl wrote: »

This is something I raised with the trainer in the BER course and was told that unless there were zone or sofisticated boiler controls then one had to assume that secondary heating was used during the summer.

thats what i was taught as well... perhaps this is one for SEI to catagorically determine...

topcatcbr · 24-01-2009 3:39pm

That was what i was told during training but when i started doing the assessments (During the HESS) and was imputting as you have suggested i got it clarified.

In fact this was one of the first things to be pointed out that most assessors were getting wrong.

sinnerboy · 24-01-2009 7:39pm

From DEAP Manual .

syd , Brian - your course instructors were wrong ( I was instructed as below actually)

I have underlined text which supports topcats posts

4.6 Hot Water Backup
In most cases the system specified for water heating should be that intended to heat the bulk of the hot
water during the course of the year. For example, supplementary electric water heating should be
disregarded if provided only for backup where the principal water heating system is from a central heating
boiler, as should other devices intended for or capable of heating only limited amounts of hot water.
Supplementary electric water heating is to be included in the following cases:
a) Where the main water heating system is incapable of providing hot water without space heating, then
the “supplementary electric water heating in summer” option is set to “yes”. In this case, the secondary
water heating fuel type is set to “electricity”.

mcm09 · 25-01-2009 8:10pm

mcm09 wrote: »

Link to one and a half story house drawing - http://www.hvva.org/hvvanews7-5m.JPG
(just to give a picture of what I am on about!)

I haven’t come across this out in the field but my own house is a one and a half story. While the room in roof option for existing dwellings it doesn’t apply to half stories. Here is how I approached it when practicing on my own house.

The external walls come up about 1 meter before the roof takes over. I include this in my wall measurements and get average ceiling height for the dimensions tab. What I am wondering about is the roof. Here is my proposed solution -

I put 2 entries for roof.

One for the area above the horizontal ceiling where you have some attic over it. i.e. the highest point of the ceiling before it starts to slope down to the external walls. This part was straight forward, I treated it like any other roof. Got the area, measured the insulation and selected insulated at joist level in DEAP.

The other roof entry is for the part that slopes up from the external walls. There are 2 areas like this one to the back and one to the front of the house.

I got the area of both and added them together for one entry.

Removed the area of the 2 velux windows to the back

Removed the opening for the dormer window to the front. This actually sits in to the wall so I removed the appropriate portion of the area from the roof and the balance from my external wall measurements.

Got the area of the roof over the dormer window and added this to my main area.

I then entered this roof area in DEAP as insulated at rafter level – insulation unknown.

I ignored the small wall areas to the side of the dormer window – I assumed this would be okay given the loose way DEAP allows you calculate the room in roof.

What do you guys make of this procedure? I hadn’t been shown a method of doing this in training so I logical it out as best I could. Any comments, criticism or advice more than welcome.

Thanks in advance

Sorry for swapping the topic back again.

Hayeser, topcatcbr, sinnerboy you guys seem to have some plenty of hands on experience ..

I am just wondering if I could get some feedback from ye or anyone else in the know on my proposed solution for a story and a half property ..

topcatcbr · 26-01-2009 9:54am

MCM09 Im sorry for not responding to your post before but i am finding it hard to read. It is layed out badly and the bullits are not helping. that said i will try and respond as best i can

Firstly you will imput the area in the room in roof in the dimensions part.

Then in the building elements section
Walls These will be imput in the walls section as normal. If they are 1m by the perimiter less window area.

Roof there is two parts to this
Insulation on ceiling. Imput area
Insulation in rafter. Imput area.

Simple as that.

I hope this is of help.

mcm09 · 26-01-2009 11:51am

Thanks for the reply topcatcbr,

I was struggling to articulate what I was thinking alright! I think you get the jist though.

I would have made a distinction between the half story and the room in roof.

My thought on the room in roof was that it was a facilitate to simplify the the partitions that the room in roof would have bordering unheated areas to its sides and give a general u-value for the entire envelope. As these areas don't exist in a half story I would have thought you wouldn't use the room in roof option.

topcatcbr · 26-01-2009 12:04pm

mcm09 wrote: »

Thanks for the reply topcatcbr,

My thought on the room in roof was that it was a facilitate to simplify the the partitions that the room in roof would have bordering unheated areas to its sides and give a general u-value for the entire envelope. As these areas don't exist in a half story I would have thought you wouldn't use the room in roof option.

You could be right but in my mind id put put less than 1.2 m high walls room in roof and higher would be second storey. Its not something iv had to deal with yet. why dont you seek clarification from sei.

lottyprop · 26-01-2009 12:58pm

When dealing with windows in a half story or room in roof situation I would

1) remove roof windows from roof area

2) not remove dormer windows from roof area (my understanding is dormer windows are "flattened out", usually the roof over the dormer covers most of the void, the rest is ignored)

Obviously all windows are counted in the windows section of building elements. I am just refering to calculating the roof area.

derickmc · 27-01-2009 10:32am

Are you sure this is correct ?

I have just completed the course and we were told for the room in roof that the the entire envelope is "generalised" i.e. roof, partition walls & windows are given an average u-value.

Therefore windows should not be removed from the roof area in the room in roof situation I would expect that this would follow through for the story and half also.

That was the impression I got anyway.

dunie001 · 27-01-2009 11:38pm

The room in roof just presumes the u-value for the area in the roof, which is too difficult to calculate manually.

It is calculated using a formula (in DEAP manual) from the average room height and floor area of the room in roof in the Dimensions section.

However I believe that the windows in a room in roof are put in seperately in the building elements section as well as the two gable walls that should probably be put in as exposed walls with the windows deducted...otherwise the windows in the room in roof are not included anywhere in the calculations.

Although I don't know how to treat dormer windows and velux rooflights in all that...I just put them into the windows section as normal...

At least thats my opinion on the matter anyway.

The room in roof only covers the areas of insulation on the side, the slope and the attic above. I don't think it includes any windows or doors as far as I know...

dunie001 · 27-01-2009 11:47pm

I recently completed a BER on a highly insulated Passive House. It came out as a B3:eek:...for the simple reason that DEAP forces the assessor to select Electricity as the main Heating system where no other system is observed.

If I could have put in NO main heating system and entered the secondary heating system as Electricity (which is the setup in the house), the Rating would shoot up to an A3 immediately...

For some odd reason, DEAP doesn't accept that some houses may not actually require any main heating systems at all...only a secondary one to boost temperatures in cold nights in winter...

The house has a Heat Recovery Ventilation system as well...

I've no option other than to give a B3 Rating, and I feel defeated by DEAP and SEI that they have that stupid backward rule.

Anyone have any idea if the situation could be battled out with SEI so that no main heating system can be selected if applicable and there is adequate proof????

brianmacl · 27-01-2009 11:56pm

I was always tought to cover my arse when doing anything with property, considering the value of it I felt it was good advice. I keep decent records of conversations and deals done and I have brought this approach over to BER Assessments.

Over that last two weeks, I have come accross a few situations that were not covered by my training course and where not in the DEAP manual. so I emailed SEI, however I have found them very slow to respond and in some cases they haven't got back to me at all. Is this unusual? has anyone else had this experience?

sydthebeat · 28-01-2009 12:00am

dunie001 wrote: »

I recently completed a BER on a highly insulated Passive House. It came out as a B3:eek:...for the simple reason that DEAP forces the assessor to select Electricity as the main Heating system where no other system is observed.

If I could have put in NO main heating system and entered the secondary heating system as Electricity (which is the setup in the house), the Rating would shoot up to an A3 immediately...

For some odd reason, DEAP doesn't accept that some houses may not actually require any main heating systems at all...only a secondary one to boost temperatures in cold nights in winter...

The house has a Heat Recovery Ventilation system as well...

I've no option other than to give a B3 Rating, and I feel defeated by DEAP and SEI that they have that stupid backward rule.

Anyone have any idea if the situation could be battled out with SEI so that no main heating system can be selected if applicable and there is adequate proof????

dunie...

could you do me a favour please...

could you run that calculation under 2008 regs and see how it comes out....

i suspect it will not comply!!!

oh, as regards the ber cert......
if you have a cert from the passivhaus institute.... you can put you BER next to the toilet rool in the bathroom....

topcatcbr · 28-01-2009 12:00am

brianmacl wrote: »

I was always tought to cover my arse when doing anything with property, considering the value of it I felt it was good advice. I keep decent records of conversations and deals done and I have brought this approach over to BER Assessments.

Over that last two weeks, I have come accross a few situations that were not covered by my training course and where not in the DEAP manual. so I emailed SEI, however I have found them very slow to respond and in some cases they haven't got back to me at all. Is this unusual? has anyone else had this experience?

Yes
They used to be good at getting back to you but since they outsourced the helpline this has changed for the worse.

sinnerboy · 28-01-2009 12:08am

dunie001 wrote: »

I've no option other than to give a B3 Rating, and I feel defeated by DEAP and SEI that they have that stupid backward rule.

Anyone have any idea if the situation could be battled out with SEI so that no main heating system can be selected if applicable and there is adequate proof????

This excellent article covers this very point in detail

http://constructireland.ie/Vol-4-Issue-2/Articles/Passive-Housing/Are-energy-ratings-letting-down-passive-houses.html

BER Technical thread

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