International Passive House Open Day 2012: 9 November 2012

 After a terrific response from visitors in the 2011 PH Open Days, we a delighted to once again open the house to visitors for 2012. These open days take place around the world, are totally free and vital in encouraging Passive House construction. These are amazing buildings to live in!


 

Located just 10 minutes from the M50 in Greystones, Co. Wicklow, experience for yourself what a Passiv Haus really feels like for the homeowner.  Ask those questions you always wanted to & get a first hand account of the challenges of building to this exacting standard. See the building systems & better living environment for yourself.

We have no links to suppliers, or builders & are independent.

Date & Time  : Friday 9, November 2012 , 0930 and 1130 am appointments available

Pre Booking required, there is no charge for these visits

Further Information, Project 2309, www.passivhausprojekte.de
About the house : passivebuild.blogspot.com

                                           Location

• Greystones, Co. Wicklow
• Just off exit 10 of the N11
• 20 minutes from the Red Cow via the M50

                                                      About the house

• Newly built in 2011,Passiv Haus certified 2012
• Floor area of 350sqm, green field site
• Orientated to optimise solar gain
• Uses solar panels & gas boiler for heating & hot water (DHW)
• Includes PHI certified triple glazing & heat recovery
• Extensive rainwater harvesting system
• Walls & floors with a U value < 0.1 W/m2K
• Very low energy bills!

Moving into a new ( passive) house & running costs

The solar tubes on the roof have been extremely effective in the supply of nearly all our hot water for a number of months. The tank did not get as hot as I had expected , probably due to a terrible summer in Wicklow and the fact its a large buffer tank (1500 litres). However the buffer tank is extremely effective in carrying over heat gathered from a sunny day into following days. Further more it is a stratified tank meaning that the water is colder at the bottom than the top, usually the top is around 50-55C whereas the bottom is around 25-30C. Will continue to monitor the amount of heat harvested from the panels over the winter so see their overall contribution is over the heating season. It has just hit the end of September which is the start of the traditional heating season & the temperature in the building is amazingly stable considering the change in seasons outside

Its been an interesting few months & am finally starting to get round to the many ( far more than I thought there would be!) list of jobs / unfinished work / finishing touches. To be honest the vast majority of these are what has to happen anyways when you move into a new house or build one.

• Putting in a base for a patio
• Installing land drains for any places water was ponding
• Putting in bushes, shrubs & flower bulbs
• Optimising heating , solar tubes and domestic hot water (DHW)controls
• Getting the heat recovery system (MHRV) set up to match our requirements
• Preparing the lawn & putting down grass seed
• Changing any locks for which tradesmen may not have returned keys
• Re-affixing any roof slates that have come loose
• Completing the set up of the rainwater system
• Organising the dozens of keys for doors.
• Paint & filler touch ups
• Emptying the garage of surplus construction materials ( gave away quite a bit on freetradeireland.ie which is excellent)
• Finishing drains, paving & paths around house
  The list goes on......& are just part of owning any house!

As regards the costs of services ( i.e. Gas and electricity in our case) , we have been monitoring these on a weekly basis and the bills are pretty close to what we expected & modelled by the PHPP software for a house this size. The biggest & most immediate change was to change services providers away from the incumbent suppliers - this is all very easily done on the likes of www.bonkers.ie and bill saving are around 15% immediately.

Final piece of news, we are opening the house for International Passive House open day, where owners /builders / designers open up passive houses around the world, for no cost, for a number of days each year.

Overview : http://www.passivehouse-international.org/index.php?page_id=262

Visit Details : http://www.passivhausprojekte.de/projekte.php?detail=2309

Getting Passive House / Passivhaus certification

Well, our certificate from the PHI in Germany arrived in the post this morning which we are delighted at & it comes with a plaque which we will have to find a spot for.

There were a few final questions over the last few weeks around solar gain & making sure that the humidity in the house did not drop below 40%. To answer these questions we need to show that
(1) we had fitted some large roller blinds on the south & west to reduce the solar gain; these have done a terrific job & are in regular use
(2) had a large amount of house plants which greatly increase the humidity in the house; the ideal RH is about 45%, but in Ireland the outside RH regularly hits 90% so it tends to be less of an issue than in mainland europe where the climate is much drier and the MHRV may make the inside air too dry. Needless to say in the last 6 months the RH has never dropped inside below 45% in this house

These may seem like little details but show the PHI interest in demonstrating that the building will be both comfortable & healthy to live in. Below is a quick snap of how the house looks today with still a lot of work to do on the garden!

Passive House Design & Construction Decisions - part 5

The last 18months of the blog have been very interesting. We are getting about 400 hits per month with the most read post has been ' How much does a passive house cost to build' which really shows that there is a lack of good information out there about what (1) what a house costs to build and (2) how much extra a passive house would cost.

Well we've been in the house now for about 5 months now and it have been an interesting time in terms of wrapping things up and perhaps areas where we would do things differently.

Paint

The main  lesson learnt on paint is to buy the best you can. Secondly it takes twice as long as you think it will, & even more if you have the final floor coverings down. We went for water based paint from Colortrend ( International Paints) based in Celbridge Co Kildare. They distribute through a limited number of suppliers who make up the colour in a mixing machine in the quantity you need, the paint is amazingly hard wearing . A stunning range of colours and better value than other high end suppliers like Farrow & Ball. We rolled the entire house in an obliterating white emulsion as soon as the plaster was dry. We did all the woodwork in a Colortrend water based mid satin off white; if I were doing it again I might more seriously consider a gloss for the woodwork given the proliferation of little mucky hands everywhere.

Building Drying Out

There is a tendency when wrapping up a build to rush the finishing, especially the installation of doors , skirting, architraves etc. Well, whatever you do dont rush it. The building when the second fix carpentry is installed should be very dry , in particular any plaster be well pink. Secondly, the timber should planed / treated / knotstopped before installation but also let sit in the building for a few weeks so that the moisture content stabilises to that of the building. If the moisture content is higher then than the building, the the timber will crack as it contracts as it dries out. Your tradesmen will want to rush to get finished, so order in time & its well wort waiting.!

Buying on the internet

We bought a number of items on the net, in particular the branded sanitaryware & taps from a German website ( mainly http://www.reuter-badshop.com). Given that the products are branded ( mainly Duravit) with international warranties ( check this before buying) then once we ordered the correct items then there was actually little risk. Furthermore if you pay using credit card then you have protection should faulty good be delivered , for up to six months. The prices were 40% less than here in Ireland but there was an 8 week lead-time on some item but in stock items were delivered in a week. They were excellent with questions We did buy some mid level taps from a UK website and that experience was less positive as the quality of the goods was simply lower than the German products. So in summary, buy good quality branded goods on the net, for mid level products then buy in the trade outlets locally.

Choosing Tradesmen

We have has a really mixed experience with our tradesmen. My lesson is document what you have agreed in advance & either email it or both sign it. Such a document means that an alterations from it will need to be documented so else you end up in a ' he say....she says....' situation eventually. No matter how convivial it all is at the start, there will be moments were selective memory will kick in. Always ask for references & check them out. In general, I would suggest buying the material for tradesmen and getting them in on day rates for the work & then monitor the quality. This is generally cheaper than a lump sum where you don't have transparency on pricing or material quality Finally, I would always suggest using tradesmen that are local, meaning within a 1 hour drive, in particular the plumber, roofer & electrician. These should be people who value their good name & have a vested interest....too often these days the work is ' hit & run' All of the above seems like common sense, but it is something that is often forgotten. To say that we were let down by many of our trademen would be an understatement, inlcuding the roofers. At the other end of the spectrum has been the electrician, Tommy & Maurice Whelan of Marathon Electrical, who have done a great job and stand over their work.

Documenting Your Build

This is absolutely key and should involve buying a small handheld HD video camera & a good high rez camera with a flash ( not a phone). The price of both would be around €200 on amazon. You should aim to regularly walk all the building walls, exterior, roof, scaffolding, skips etc... twice per week to show (1) progrees (2) technical details as they are being constructed (3) materials on site with batch / quality marks. We have had cause to produce some of these photos already & they were simply invaluable.

Gardening

Even though we're in the house a few months, some parts of the garden were planted over a year ago. If youve a large area to plant then its best to use bare root plants or whips ( little bare root trees). These take a while to develope but are a fraction of the price. Likewise now that the construction boom is over, there are many plant nurseries ( not gardencentres!) that have root balled trees - many of which can be 6m tall – which can be planted & have an immediate visual impact. All these type of trees / shrubs need to be planted by the start of April and well watered in their first season. Trees like silver birch are typically used in passive houses to give solar shading during the summer months to reduce building overheating. Gardening lesson over!

Paths Around the House

We put a 750mm concrete path around the house with a small quantity of smashed glass & pebbles pushed below the surface when it was drying. We will grind this back a few millimeters to give a polished concrete finish & the fall is away from the building of course. Between the build and the path there is a large gap with a land drain below the surface with a covering of grey pea gravel. We put the structure / pad in for a patio down too as this involved some heavy equipment and if done in the future would have shredded the lawn that is about to be planted.

Lighting

The best value & designs are to be had by going to the trade lighting outlets who will stock enormous ranges from the likes of Philips & Massive. These sellers do not have retail outlets but have good catalogues with all the dimensions. I would say these suppliers are 60% less than the usual lighting centres we all know. Have just done an exercise of replacing a few halogens with LEDs. Got these online from futureled.ie and whilst the quality of the bulbs if great, the light from LEDs is a harsher white. I did order warm white LEDs which are supposed to mimic the yellow of halogens but even then the 3 types I did order, each have a very difference ' warm white' colour, so do definitely order the LEDs in small quantities first as they do cost about €6 each. Switching the bulbs is a very straighforward job. The electical power saving is incredible; for example I replaced 50W halogens with 3W LEDs & the latter are actually brighter than the halogens.

Will keep working through my list of observations on the design and construction of the house. If there are certain topics you would like to see addressed, then let me know.

Technical FAQs on building a passive house No. 1

Have received a lot of questions via the website, house visitors and looking at the search words for this blog, so have decided to answer the first tranche via an FAQ:

How many passive houses are there in Ireland?

I reckon at the moment there are about 10 certified in this country but many more in the pipeline.

Search function on PHI website: http://www.passivhausprojekte.de/projekte.php?lang=en

UK Passive House Map: http://www.passivhaustrust.org.uk/projects/

What is the PassivHaus Institut?

The Passivhaus Institut (PHI)was founded in 1996, by Dr. Wolfgang Feist, as an independent research institution. It employs physicists, mathematicians and civil, mechanical and environmental engineers, performing research and development on highly efficient energy use. Based in Darmsdadt in Germany, they are the though leaders in the field of lowe energy building design. The PHI certify the design and construction of ' Certified' passive houses and sets the exams for professionals training in the area. The use of the term ' passive house' or 'passivhaus' is not trademarked so so whilst the term is often used casually, just like the term 'Hoover' or 'Tupperware', it is only buildings that have official certification that have genuinely & officially reached the quality standard demanded by the PassivHaus Institut

Wed address: http://www.passiv.de/

What is a passive house certificate & how does it differ from a conventional build

In Ireland, & maybe in other jurisdictions, the design of any house is undertaken by an architect with regards layout, planing permission, massing etc & the structural design undertaken by a structural engineer. These professionals with then come up with design details that the contractor should use. The construction process is then 'monitored' ( whatever that means) – perhaps via 4 or 5 site visits - by an engineer / architect and 'self certified' ( hard to believe...but true) as meeting the quality standard required by the building regulations and Technical Guidance Documents. There is little inspection of builds by building control or local enforcement function.

The process of certifying a house is an additional leg to the process whereby the energy demands of the building are modelled, via an excel tool call the PHPP ( Passive House Planing Package) to meet strict requirements. Then to confirm that the build meets the requirements, photos, details of material, junction details and airtightness test results are detailed. These are send to the PHI in Germany or the local approved certified for certification as meeting PHI Passivhaus design and construction requirements.

The Passive House Enyclopedia : http://passipedia.passiv.de/passipedia_en/start

Self building a passive house a good idea?

Not sure I can answer this question in anything less than 5000 words! In short, any self build should not be undertaken lightly; a self build of a passive house requires a whole different level of attention to detail in design and construction – much of which is new to the vast majority of site personnel & tradesmen. As mentioned earlier in the blog , in a tight market everyone is selling something & it pays to be a sceptical & informed client. Bottom line is that savings of going self build may cover the additional costs of a passive house over a more standard build.

Disadvantages of a passivehouse

The single biggest challenge is the additional capital cost of the build.The second biggest one – according to my wife – that there is no open fire!

Does a passive house have a heating system

Yes, unless there are sufficient solar gain, heat losses from other sources ,enough people and activities to make the building a 'comfortable' temperature. The key term here is ' comfortable'; there are people who think 21C is toasty & necessary; other say that anything above 17C is far too warm & stuffy. In addition, bedrooms should typically run a few degrees cooler. In summary, one man ( or woman's) hothouse is another man's ice house.

What sort of heating system does a passivehouse have?

There is no one answer to this & very much depends on your location & requirement. The key thing is that it should be a small & efficient unit, given that the building will overheat very quickly Options out there include

• Preheating the air on the way using a water to air radiator
• Sealed fires
• Radiators
• Radiant panels
• UFH - water or electric

What materials are used for air tightness?

These depends on the surface

• Floor :A screed cement / concrete layer is accepted as airtight
• Walls : 18mm Orientated Strand Board ( OSB) – it looks like a plywood – as the internal sheathing board is generally accepted as being airight in the long term. The joints between the boards are sealed using airtight tapes e.g. Siga tapes. Thinner boards are much less airtight but are cheaper & easier to work with.
• Roofs : working at height with OSB is very difficult due to their weight. The more common approach is to use various proprietary membranes. These membranes are also used at some of the junction details to ensure air tightness

Windows in a passive house

In general where possible, at a design stage the room layouts is optimised so that rooms that need natural light , e.g. Living rooms, kitchens, are south facing ( to capture the benefit of solar gain) and those that don't e.g. Utility rooms, bathrooms are north facing. There are many windows are certified by the PHI as meeting their specific energy loss requirements ( this usually refers to the frame which is generally manufacturer specific). Other important components though include the glazing panels, spacer that separates the glazing & the fill gas. The frames are made from the usual materials : woods & PVC. There are a number of questions about the longevity of PVC frames given that the triple glazed panels are extremely heavy and I would look for a manufacturer to have a long track record in case the PVC sagged over time. Passive certified windows are significantly more expensive & bigger than standard windows we are all used. That being said, they are exceptionally solid & sound proof .

Foundations ina passive house

There are a large number of proprietary insulated foundation & slab designs on the market but as previously mentioned they are extremely expensive. It is definitely possible to achieve the same levels of insulation and thermal bridging using readily available materials such as EPS. There is a book of accepted Passive House design details available on Amazon which will suggest some options. As a measure many modern houses have floor U values of about 0.16 W/m2K; for a passive house you are looking for about 0.1W/m2K

Why did you use panelvent on the roof?

As a sarking board to reduce the impact of wind on the roof level insulation as we used a warm roof construction. Panelvent is a 9mm wood fibre board which is rigid but moisture permeable.

Running services in a passive house

Really no different to any services layout – keep it simple when possible & keep the runs short. Any good design should stack bathrooms on top of each other to minimise runs. Levels of insulation of all services very high by comparison to usual Irish workmanship standards.

If you have a question that I can help resolve , would be happy to answer & post in the FAQ section.

First observations from moving into a passive house

Well we've moved into the new house now about six weeks and its been an interesting few weeks, have noted below be first observations on the house and how it differed from the previous house we lived in. Firstly its worth saying that the previous house was 60 years old, antiquated heating and single glazing...so comparing the two is like comparing apples and oranges.

Even building temperature

The thermal comfort of the build is so incredibly consistent and even, the building is a dead steady 20C. The air has a freshness / crispness I've really only noticed in passive houses. There are no cold areas, draughts etc...at all. This has some very simple implications ; recently we had a 4 year old birthday party and the kids were happy to play in the hall as it was a warm as every other room. Similarly, you don't have to heat a room if you plan on using it...its just the same temperature as the rest of the house.

Impact of the MHRV system

The MHRV system we are using is a PHI Certified up from Dantherm supplied by Beam Systems. The unit does and excellent job of distributing heat through the building, , removing odours and humidity. The unit is virtually silent and was properly commissioned upon installation. I'll do a detailed review of the system design, installation and operation at a later stage. I had expected that the undercut on the internal doors required by the MHRV would result in noise , but its simply not the case & they make no difference.

Triple glazed doors and windows

The level of thermal comfort and sound insulation from the glazing is amazing – the vast majority of external sound simply can't be heard – that includes cars outside, buses, wind , trees etc...The impact on this is that may of the internal sounds can appear magnified as the background noise were are used to is simply not present. Given the size of the frames, this make the central mullions on split windows quite large, the windows are either fixed ( as 50% are) or are fully operable 9 tilt & turn)

Low building humidity

The previous house we lived in had regular humidity levels between 70-90% which we believe resulted in request colds and chest infections. The new house has relative humidity of between 40-50% and this rises over the course of that day as there is activity in the house.

Natural light

Given the thought that went into the room layouts and orientation at the design stage – this is very much in line with Passiv Haus design principles. In general the rooms where we spent most time are very well naturally light; other rooms such as utility, bathrooms and no or little glazing.

On the flip side, there are a few things that I miss from a more standard house

• An intense heat source such as a fire / stove would be nice to warm up when coming inside; the reality is that a stove would likely overheat the house though & its actually pretty cosy
• An kitchen extractor which expels kitchen odours cannot be used due to air tightness requirements – instead the cooker hood is a recirculation unit with removable dishwasher safe aluminium filter & the cooking area has an MHRV extract point
• Energy efficient bulbs can take a while to heat up / go the right colour...the technology is getting there though

So - in summary the building to date - in mid winter - has been extremely cosy, the kids definitely seem healthier with less cold & sniffles. The quality of the living environment - day light, low humidity, consistent temperature  - is exactly the reason we build the house in the first place.The observations above are just a short summary and I'll deal with the hows and whys in more detail in further updates.