PassivHaus Refurb

[Mark Siddall]

It won't suprise you to see which EU country has no examples in the Best Practice Section.

http://www.energieinstitut.at/Retrofit/?to=0&forward=S_19&id=2f7ea24da6318ff2e3daa7002bbdaf8a&dmy=4fa4f1854b6a146862caf26689a38e7e

Mark

[Nick Grant]

Why at the Passivhaus conference did the audience giggle when it was announced that all new UK buildings would be zero carbon by 2016?

[Andy Simmonds]

We are aiming to build a PH extension and start the PH refurbishment of our own home in Hereford in July this year. Here are the planning application drawings (we are waiting on a decision after a positive meeting with the planning officer). The detail is slowly being worked up....

[Andy Simmonds]

Today we received planning permission for this project after a positive response from the planning committee. Have had it modeled with PHPP...will post results in due course.

[Andy Simmonds]

Some pics of work in progress -
http://www.aecb.net/PDFs/To%20Aug%2020_attic%20roof.pdf

Update:  pdf has now been updated with one that has some annotations over the pictures.

[Dave Howorth]

OK I was impressed by these pictures and today I read the Carbonlite standard saying that refurb to passivhaus is established technology. Previously, I'd assumed a new build was necessary.

Could somebody kindly point me to the established wisdom?

Thanks, Dave

[Andy Simmonds]

Experience on refurb to near Passivhaus levels for whole building performance (hard to reach, or not worth reaching, the new build target on existing buildings) exists mainly abroad of course, and on this project we have simply applied the principles underlying CarbonLite, used PHPP to model the house -and make design decisions, and drawn on general advanced practice where ever we can find it - USA, Canada,Austria and Germany etc. PHI staff have given a few useful pointers, but are terribly busy.

Apply basic PH/CarbonLite principles first, use PHPP to make design decisions and model results, and aim as close to the new build targets as possible.

This will be written up as a full case study, and I will post for example air pressure test results as soon as carried out. Otherwise is an experiment at present, rather than demonstrating established wisdom.

Personally I would like to see a Silver standard refurb carried out on a house - but as a full set of integrated measures in line with CLP guidance and using PHPP.

Anyone doing this?

More pictures when I can.

[Steve Macken]

Andy
- not quite a house, but we're about to submit plans for two holiday lets on the farm which will be conversions of two semi-detached redundant farm buildings.  One is sandstone built ca. 1840, the other being brick built in the 1950's.   Our focus is on cost engineering, whilst speciifying an energy standard which comes at least close to or just within Silver.

Experience on our Silver house has helped of course, but there are limitations on these exisitng structures where external features (eg sandstone walls, openings etc) need to be maintained for planning purposes and internal space maximised within an exisitng envelope, which can lead to compromises.

General details -  which we're about to start working up with our architect and builder - will involve an internal 6" timber frame, which, with good insulation and minimum bridging, can just achieve the Silver standard u-value, with concrete floors floating on foam (been there, done that, and it works well!).  The cheapest way of doing the roof is using attic trusses, but of course these are a pain to make airtight at the wall junction.  That said, I like your method of sarking the roof then fixing the I-beams on top to a carry the insulation which could be adapted for a trussed roof.

Any alternate ideas on the roof would be welcome!

Steve

[Andy Simmonds]

Great! Are you going to have a go using PHPP to do design modelling?

[Andy Simmonds]

There is some more on my project here:
http://simmondsmills.com/home_page.php?id=15
and pictures of work in progress:
http://simmondsmills.com/project.php?id=31

[Andy Simmonds]

UPDATED POST on 25 Feb 09

Green Building Magazine article on project below. Very good Romanian workers fitting 250mm neopor type EPS insulation to the house and extension this week. Will try to upload new photos on simmonds.mills website soon! Unfortunately potential Ecobuild talk slot on this project seems to have disappeared unaccountably. Still, Mark Siddall will be showing a few pictures in his Ecobuild slot.

I have amended the article and uploaded it again (on 25 Feb 09) - having realised that the the Primary Energy Limit was meant to read as 78 not 120 kWh/m2.yr

I have to say the 'magic heat effect' (lots of insulation, very few small radiators..lovely warm rooms) has now kicked in (all insulations complete), so on final airtightness measures, then air pressure test maybe next week.

[Mark Siddall]

It is worth noting that this change from 120 kWh/m2.a to 78 kWh/m2.a will also mean that, according to CLP Standards, the CO2 emissions will fall from 22 kg/m2.a to 15 kg/m2.a

Mark

[Andy Simmonds]

Do check out p20, 21 etc here (http://www.aecb.net/PDFs/carbonlite/AECB_VOL3_EnergyStandard_V6FINAL.pdf) for further clarification of Primary Energy Demand.

[Andy Simmonds]

Our first pressure test, before the extension wall were plastered came in at 1.56. We found a number of small leaks in areas of membrane, and also noted how much air seemed to be coming in through the mortar joints (mainly perpends) of the concrete blockwork extension walls. The walls are now being plastered and we still hope to get to the 'magic' CarbonLite target of 0.75. The full air test report will be uploaded when ready. Generally no 'large' leaks were identified so after plastering any remaining leaks are likely to be associated with multitudinous 'micro' leaks through brickwork assumed in the strategy to be airtight (e.g., see article describing basement/ground floor/wall details). Even at 1.56 perfectly adequate for proper functioning of the MVHR. More soon...

and yes, it would be nice to get the job finished! 3 weeks?...

[Andy Simmonds]

You can see more info on where this at at www.simmondsmills.com (projects section). Air pressure test final = 0.97 m3/m2hr@50 Pa. I will add here for those of you who don't want to go to another website the AECB conference presentation on the project. On the website, I have put up a thermography report...with lots of nice infra red images....mmmm, lovely.

Oh, I have to say that the house is very very nice to be in...and I am thinking here about the thermal environment, the air quality - all those things you read about in the Passivhaus documentation: it's fascinating to be in a Passivhaus Refurb, and to 'feel it'!

The wild meadow flower roof is beautiful too...it's not all about energy you know...