The populist view of the ‘cowboy builder’ breeds a climate of mistrust between the public and the industry, and within the industry itself. Would it not be advantageous for all, if the construction industry was respected in the same way as say that British motor engineering now is? Where becoming a builder/site worker was not the last resort when leaving school at 16? However upskilling site workers is only part of the story.

Motivation is as important as knowledge to closing the performance gap. Mutual respect for everyone’s area of expertise, the acknowledgement of risk in undertaking innovative  design and, crucially, acknowledgement of financial risk,  between all members of ‘the team’ is absolutely crucial for good workmanship and building performance. (The team includes everyone from client, designer, QS, contractor,  and tradesman to site labourer, and not necessarily in that order). A site worker will, in my experience, always respond positively when asked for an opinion on their own field of expertise, thanked for ‘going the extra mile’, praised for good works, etc.

Here are a few pointers that I believe will engender the right environment for a build process to be successful;

•    Absolute client commitment and understanding of the core issues.
•    Architect to be aware of their Master Builder ancestry and to realize the shortcomings of the ‘gentleman architect’ mentality.
•    Buildability of design, function before form.
•    Relatively long lead times before commencement on site, giving space for well thought through detailed design and subsequent comfort time for good estimating and programming of the build process on site.
•    Partnership contracts allowing early involvement of contractor/builder/craftsmen, to facilitate input into the design process and to gain ‘ownership’ of the task.
•    Value engineering to be reclaimed from cost cutting, where value is seen in reference to performance (in its widest sense) not just in profit margins.
•    Moving away from sub contracting to in-house trades, offering more control and continuity.
•    Realistic contract times and realistic extensions of time.
•    Fair payment terms and on time for contractors, suppliers and sub contractors.
•    Steer clear of lowest tender mentality which inevitably leads to disputes and bad workmanship.
•    A code of conduct for buyers which gives transparency of procurement procedures allowing security to suppliers and sub contractors to plan ahead to calmly provide the most appropriate materials and labour.
•    Maybe, above all, strong leadership.

I could carry on with this list, but I am just trying to point out that, as with all work related activities, good management procedures lead (hopefully!) to a good final product. Site managers and workers will respond well to good design and good contract procedures, allowing them to concentrate on delivery. It is my experience that when the momentum of the build is tripped up by designing detail ‘on the hoof’, particularly where the operative is working to a price, morale tumbles and quality will suffer.

Site managers and site workers are, by nature, practical people who are more receptive to the learning process when faced with an actual project. We are waiting to see a Certified Passivhaus Tradesman Certification course from Germany which was promised late last year. It may well be that for a Builder to be successful in gaining a ‘Passivhaus’ contract he would have to put a certain percentage of his workforce through the course. Could we use such a method for all ‘good’ construction where clients would insist on potential builders having passed an exam?

Passivhaus methodology can, I believe, be used as a framework for training of good onsite practice. Passivhaus is fairly prescriptive but liberating at the same time. Performance criteria have to be met to reach certification, everyone from client to site labourer has to work towards the same goal or it is a failure. Dilution of build quality is far less possible than the with the UK standard.  Maybe Passivhaus will be deemed a step too far, whereas the phrase Fabric First might be seen as more acceptable.

Communication is paramount. If someone has not understood an instruction, it does not necessarily mean that they are stupid. In fact the communicator might be deemed as stupid for not communicating in an understandable format. A tradesman’s existing experience and skill should always be respected and any new knowledge is extra to their skill base, stressing that the industry is changing fast and that they are part of that improvement change. They will be more in demand for their new expertise.

Passivhaus might be deemed as too narrow with its emphasis on thermal performance, but when we run Passivhaus training sessions to any interest group, housing officers, architects, builders, site staff, for example, we base it around four basic topics which when expanded can help to close the so called performance gap.

•    Insulation
•    Minimizing thermal bridging
•    Air tightness
•    Minimizing thermal bypass

We find that these subject areas or principles appear to be easily understood at all levels. For example ‘Insulation’ would include material properties, lambda values, understanding U values, appropriateness, application, and so on. ‘Air tightness’ would include ventilation principles, vapour control, interstitial condensation, etc. We also find that there is a more positive response to a course where actual builds are featured with plenty of photographs; too much theory tends to turns practical people off!

Because the comfort is in the fabric of the house, the temperature will change very slowly. Opening windows in the house after (for example) cooking kippers give a through flow which changes the air but doesn’t affect the house temperature because the heat is in the fabric. For things like strong odours we could use the boost on the MVHR, but opening the windows is just that bit quicker.

Under the microscope

Leeds Met University are still doing ongoing readings and measurements of the house, including: temperatures in five rooms; humidity; meter readings; external temperatures;  CO₂ levels etc.

So far, they have found that the indoor temperature range is usually within 2 degrees – they were amazed with how stable it is. The Leeds Met team have been finding it useful to get information from occupants as to what’s going on in the house corresponding to fluctuations in their measurements and can ask us what happened on a certain day.

Kate’s birthday party even showed on the Leeds Met graph. We had a party with 11 extra people heating up the house – immediately you can see on the readings that the temperature stayed higher for longer  on that day. The Leeds Met team can also see from their readings when we’re away because we’re not adding our body heat to the house, there is a slow decay of temperatures. When we return, the internal temperatures go up. Passive houses work best with people living in them, body heat, cooking, showering, electrical  equipment etc, all contribute to the heating.

The house’s baseline temperature was originally set at 21 degrees, so that when room temperature went below 21, the heating came on (duct heater, 2 towel rails and one radiator in the living room). However, this meant that the house sometimes got too hot as there can be a time-lag before the heating switched itself off again. I think initially we thought the house was going to be an automatic house which would run itself without us having to adjust any of the switches etc – but we’ve realised that sometimes we just need to turn the heating off manually.

When we did our January monthly meter readings we were surprised when we found that we had used 147.28 m³ of gas in the previous 2 months. However as this was just average of 73m³ per month it is still within reasonable limits for that time of year and does also include hot water usage (solar thermal panels were covered in snow for some of that time). Over December we had a really severe cold patch for about 14 days. Over that time the heating was on from 6.30am-7.00pm or sometimes 24 hours a day. Actually during some of that time we overheated the house and it became a bit uncomfortable.

Solar space performance

During those extreme conditions in December, it was -18 outside and there was a ‘thermal  battle’ going on between the heat in the fabric and the cold outside. As had been anticipated  the coldest place in the house was in the solar space – it just felt colder up to about 6 inches in. When most of the surfaces in the house were 20 degrees C in the house the floor surface  temperature might be 17 degrees near the edge of the solar space.  In a standard house the whole house would feel cold but in the Passivhaus the cold was just creeping in..

Regulating the heating timer controls

Since then, we’ve been using the heating a lot less. Now we’re finding that we can just run it for a few hours and keep comfortable all day. We’ve been generally putting the heating on from 6.30am -9.30am (3 hours instead of 12 hours) is enough on a normal February day.  We have also now adjusted our baseline temperature down to 20 degrees. On a sunny winter’s day we don’t need the heating at all – the sun will warm the house to  21 degrees and slowly decay  so that at 10pm at night  it might go down to 20 degrees  – the solar heat we can gather has a very long decay rate away and that’s what makes it comfortable. We’re finding the temperature is fairly stable at a comfortable temperature.

Making sense of the gas usage

One of the difficulties when analysing gas consumption, is that you can’t separate the gas usage for space heating from hot water heating or from cooking. The only way to separate them out would be to get specialist meters on each aspect of gas usage, which sounds expensive and a hassle.  However, we have been cutting down the length of time we put the hot water on for and are finding that that is having a big impact on our gas consumption.

Humidity/ dryness

Another thing we have noticed in the winter was that the warmed fresh air sometimes became quite dry – this mostly affected Geoff at night times  especially  if he had  a cold – he would waking a couple of times with a very dry mouth. We have come up with a really easy solution to this:  a bowl of water on the dressing table or – even better due to greater surface area – leaving a moistened  tea towel  on the back of a chair overnight. This serves to releases humidity through the night and ever since we’ve done that we’ve not had one problem with over-dry air in the night etc. Needless to say, wet washing dries overnight in the house! We believe later models of the PAUL MVHR systems tackle the dryness issue by offering the option of humidity control/recovery. . More houseplants might also be another solution!

Frozen MVHR

Three days before Christmas the MVHR condensate pipe froze up. It stayed frozen for 3 days – mainly because the system is housed in the garage – so we had to put an electric heater on to thaw it out. Our washing machine in the garage had also frozen earlier in the extreme conditions and the same thing could happen to condensing gas boilers. Going forward, we will need to keep an eye on the condensate pipe in sub-zero conditions and we’re looking to insulate the garage for next winter. If we had had limitless money we would probably have insulated the garage first time around.

So the winter has thrown quite a few new lessons for us to help us fine-tune the house and learn to ‘drive’ the house. We’re still learning and next year our bills will reduce again because we won’t overheat it in the winter – but you don’t know what you’re doing until you do it!

http://www.building.co.uk/technical/sustainability/passivhaus-diaries-life-at-denby-dale/5008945.article

Normally the temperature of the house stays around 19-20 degrees but can go up to 22-24 if we leave the blinds up. The sun does impact but it impacts very locally – but then it does get into the ‘thermal mass’ but only ever so slowly. So you can sit somewhere and it be 24-25 degrees in the sun and go somewhere else in the house and it hasn’t caught up because it’s not in the sun.

During the week we kept the heat from the sun in so that the walls went up to 22 out of the sun and then that warmth ‘decayed’ ever so slowly into the evening. So you can tune the thermal mass by controlling what heat you give it. It’s good and comfortable and warm.

Bills

The solar thermal system on the roof meant we didn’t need to use the boiler from April to September– the boiler has been sat there wondering whether it’s been connected. The only gas we used during that time was for cooking.

The first quarter estimated gas bill – presumably based on typical bills for this sort of house – was £888. I gave them the actual figures from the meter and so it was revised down to £31!  This was for 46 units of gas and included standing charge rates. We also keep a note of the meter readings per month. The gas use for August was 59p. We really got riotous in September – it went up to £1.32.

People have asked us if we would have wanted a wood-burning stove as a focal point for the house. We haven’t found this a problem – it was a compromise– the most important thing for us was having a Passivhaus that performed. Instead of a fire we’ve got the sun space and looking at the outside garden is our focal point.

Drying clothes

In answer to the question of how you dry clothes in a Passivhaus – we use a drying rack in the study which has the advantage of also being near to the hot water cylinder. Because of the house’s warm dry atmosphere, we’re finding our clothes dry overnight.

Now award-winning!

We were very surprised – and delighted – to win Client of the Year at the RIBA White Rose Yorkshire Awards 2010. The house also won several other awards – including Sustainability and Housing. We were all very chuffed – definitely a great team effort and an enjoyable night out on the ‘red carpet’!

The original design outside the solar space was going to be a brise-soleil – (a permanently fixed structure for summer sun shading) with a pergola to provide summer shading downstairs. But we decided against the brise-soleil idea because it reminded us of prison bars and we wouldn’t have any control over it. Instead we had some electronic external shutters installed which work beautifully you can bring the shutters all the way down, have them half open (so you have lovely dappled light) or all the way up. In winter as the sun gets weaker we don’t need the blinds. Now we’ve lived through the summer in the house we also realise that we don’t need the pergola for shading. We might still put one out there – but it would be as an attractive feature rather than a necessity. It’s the same with the greenery. We’ve always wanted to live in a conservatory with ‘wrap-around’ foliage – which is why we were growing the tomatoes and cucumber inside the solar space – and then we realised that we don’t need that because all the greenery is out there – through the massive window of the solar space.

Gardening efforts

CO2 probably doesn’t build up too much in a Passivhaus due to the MVHR system supplying adequate fresh oxygen-rich air so it’s interesting to see what, if any, impact this has on the plants in the house.

Growing tomatoes in the solar space hasn’t really worked – they would be fine in a greenhouse but in an airtight Passivhaus the green fly have nowehere to go …When the Mayor of Kirklees was here opening the house I could see people swatting the greenfly away, so we’ve given up on them – they also didn’t seem to grow many tomatoes. We grew some cucumbers as well and they fruited little tiny cucumbers which then just shrivelled. Normally in a greenhouse you’d be spraying all the time but obviously we didn’t want to do that in the house. The banana plant’s fine though and the passion flower vine is doing well and as grown around the internal space metal structure (which will ultimately contribute to summer shading).
We’ve never had an orchid flower before we’ve found that orchids seem to do well in Passivhauses as is the cyclamen seems to love it in here – it just keeps on flowering.

So gardening-wise it’s still a matter of finding out what works and what doesn’t work in the house.

Air quality
Air cleanliness was one of the things that appealed to us about Passivhaus and we were also keen to use natural paints and natural materials in the house. We painted the house ourselves using natural paints – and because the paint didn’t off-gas we didn’t have to open windows while we were decorating .

We chose some clay plaster for the internal walls, which is supposed to take in excess moisture and then release it when the atmosphere gets too dry etc. If there are peaks and troughs of humidity – the clay plaster is supposed to act a buffer for this. This was recommended to us by a guy in Austria who was a plasterer and his children were asthmatic. It has an attractive finish as well and doesn’t need to be painted so it fitted our low maintenance criteria. In terms of condensation in the house, we’ve noticed that when you have a shower – you get a certain amount of condensation and steaming up on the mirrors etc – but it clears by the time you leave the bathroom – probably an indicator of the effectiveness of the MVHR

It was always on our agenda to have a house that was going to be easy to clean. We’re terrible at cleaning – one of the plusses of having the Green Building Store training day visits is that forces us to clean. Thanks to the flooring and smooth surfaces in an hour and you’re done –it’s very easy to clean – the flooring we’ve chosen doesn’t trap the dust (bamboo in the sitting room, wood and stone elsewhere).  A comfortable and dust-free environment is also part of the Passivhaus philosophy.

Our main issues with moving in have been sound, light, heat and smells. Not all these are to do with living in a passive house but concerning the design of the new house and what we have been used to, having lived in a traditional stone built 300 year old terraced house for 32 years.

The light has been the most noticeable.   Early morning sun streamed in through the east facing window on our first morning.  We opened the bedroom door and the corridor was effused with warm light.  The light from the south facing windows, floods the house.  We were fortunate to be able to utilise a plot of land which is south facing and meets the favoured orientation for a passive house.

Passive house triple glazing provides a calm, extremely quiet environment.  However, the way we have designed it on the inside with wood floors throughout and the open plan layout, means that any noise created echoes throughout the house.  We shall see if we can live with this, or whether in time we will feel the need to close off the kitchen or lay more carpeting.

Summer overheating is a problem we expect to address.  As ‘flaming June’ British style this week has meant temperatures teetering towards single figures, the house has not had a true test yet.  So far when it has been warm, we have lowered the external shutters completely providing a muted dappled sunlight in the living room – and guess what?  We opened windows!  We can get rid of hot air rapidly by opening the top window in the sun space.  We noticed before when work was still being done on the house, that leaving doors or windows open for a while did not make a significant difference to the temperature of the building.  With the heat in the mass, temperature changes slowly.

And now I come to smells!  With the open plan layout downstairs, we thought odours would pervade.  We haven’t tried the ultimate test yet – grilled kippers!  We make sure all internal doors are shut and the MVHR does the rest.  The smell of fried onions was most noticeable outside by the external vent – it works beautifully and without a sound! If I can raise the delicate matter of humanly created odours, before entering the toilet we press the boost button and the MVHR does the rest!

The highlight of the week was to entertain our guest from Germany, Witta, the partner of Wolfgang Feist.  She was delighted with the house and especially pleased to see the ‘Certified Passive House’ plaque on the wall.  She gave us leaflets from the International Passive House Association and Geoff enthusiastically signed up for something which I only later realised meant we would be opening our house to all and sundry in November !

We are delighted with our house. It is comfortable, warm, clean and airy.  We want to keep it that way.  What we are still dealing with is the 32 years of hoarding – memorabilia if you’re being kind, detritus and clutter to be more frank.  We don’t want to mess up our new house!  We might have moved in body but we’ve got an awful lot of boxes still to deal with! The clean lines, open, quiet, comfortable space is excellent!

This has been a long one the first time of writing – don’t expect as much in the weeks to come!