Passive House

Ventilation and Heating System

2008-02-19T06:45:00.001-08:00

The ventilation and heating system was installed from November 2007 to January 2008.

The heat pump and boiler.

Air is circulated around the house through pipes in the ceilings and walls.

Underfloor heating pipes in the main bathroom.

Silencers stop noise travelling from room to room.

Heating pipes in the walls. These are only necessary in a few places.

The Clay Walls

2008-02-19T04:18:00.000-08:00

A very distinctive feature of our house is the clay walls. The clay helps to optimise the humidity
in the house, is a natural and safe material (thus adding to the healthy living environment), and looks gorgeous! However, applying it to the walls is a labour intensive and time consuming exercise. By the time it is finished, it will have taken three to four months of one to three people working on it most days, to complete it.

As this method is still quite experimental, some thin cracks unfortunately started to appear in some of the finished walls. The way to prevent this is to apply a layer of gauze to the base coat of clay (using clay) before adding the top coat (the suppliers of the clay had originally said that this wouldn't be necessary). Several of the walls have had to be redone, but at least the problem was spotted before most of the walls were finished.

5 January 2008. The master bedroom. The walls can be left in the basic clay colour, or different coloured sands can be used to make the top coat of clay.

19 January 2008. One corner of the living room.

21 December 2007. The living/dining rooms. The rounded edges look lovely!

December 2007. The base layer of clay in the living room and dining room.

Reeds were stapled to the wooden interior partition walls so that the clay would stick to them. Emma’s dad did most of the stapling when he was over in November. Emma’s parents had come over to help with the move, but found themselves doing building tasks instead!

As reported in previous blogs, unfired clay bricks were used to add insulation to the insides of the exterior walls. The base layer of clay could go straight onto these.

A thin wash of clay was painted over the reeds to make sure the thick clay would stick.

In November, Emma's parents went to the south of Slovakia near the Hungarian border to buy reeds from an old cooperative farm. It was a good challenge and cultural experience for them!

Open Door Weekend

2007-11-16T07:19:00.000-08:00

From 9-11 November it was the Passive House Open Door weekend in Europe. Our architects put on presentations for the press and public, and about 250 people visited the house over three days, including a TV crew, lots of newspaper journalists and a bus tour!

Display of the clay that is going on the walls. We can choose from several different textures of clay.

Display of top coats of clay. Different coloured pigments can be mixed into the normal coloured clay to create a variety of natural colours. We will probably leave some walls the natural colour (see above photo) and then add one or two coloured walls to each room for a contrast. We will not paint the walls at all.

Hemp insulation being used in the roof and some interior walls.

"Wattle and daub". Reeds are put on top of the wooden interior walls and then a base coat of clay is put on top. The final layer of clay (see picture above of samples) goes on top of this.

Adam and Alex in the sandpit.

The outside of the house is almost finished, but they ran out of wood, so more is on order.

The ventilation system was installed in the week of 5 November. Some pipes will remain visible to prove that we have an alternative system. Fibre glass has been used as insulation in some interior walls.

The water pipes in the downstairs bathroom.

The electric wiring in the kitchen.

The ventilation pipes and the frame for the ceiling in one of the bedrooms. The box with the red stripe is to prevent noise travelling along the pipe.

The clay bricks have been laid inside all the exterior walls and on the floors for insulation. Several more layers of board and wood have gone on top of the floors, which are really sound proof (Alex tested them!).

Walls and Ceilings, Plumbing, Electrics

2007-11-16T07:00:00.000-08:00

When you are having a house built, you don't have time to update a blog! A lot has happened in recent weeks: mainly to do with the interior fittings. Also, at the end of October we had to move out of our flat. The buyers had paid for it in August and agreed to let us stay on for a few months. As the house is behind schedule, we are now living with my amazing friend and her two children in her huge house in the village next to ours. 15 October 2007: Adam helps the plumber install the toilet.

Alex and Adam put all the pipes in order.

In mid October the electric wiring was also installed and clay bricks were laid as interior insulation. The bricks have not been fired, in order to help ensure optimum humidity in the house. They have been laid using a German technique that does not need mortar. Clay 'plaster' will go on top.

9 October 2007: Oak cladding goes up on the top half of house.

29 September 2007: The final downstairs ceiling.

Detail of mesh and plaster on bottom half of house outside (obviously not finished!).

Blower Door Test

2007-10-14T06:49:00.000-07:00

On 21 September 2007 the first blower door test took place. This test measures the ratio between the volume of air that is leaked within one hour (when via the blower door the house is either under or over pressurisd by 50 pascals) and the total volume of air in the house. For a house to be classified as a passive house, the ratio must be 0.6 or less. The result of this test was 1.2, which meant that some work still needed to be done to tape over holes and gaps, mainly in the roof and around the windows. The second test was done on 9 October 2007, and the ratio was 0.55, so the house meets one of the passive house criteria!! This is the best result that has ever been measured on a house in Slovakia! We will do a third test later, which should have an even better result, as more insulation, plaster, clay, wood, etc, has yet to be put on the outer and inner walls. For more info on blower door tests go to: http://en.wikipedia.org/wiki/Blower_door

The blower door.

Software is used to calculate the measurements.

Testing for leakages.

This was an interesting event for lots of people. Representatives from the Architectural Faculty, Passive House Institute, and the various companies working on our house attended.

The builders make sure that all of the gaps are covered with special tape. See "15 and 16 July 2007 - Air Tightness Tape and Beams" blog for more information.

18 September 2007 - Windows Go In

2007-10-13T23:48:00.000-07:00

On 18 September 2007 the windows went in. They came from the Czech company called Janosik (not to be confused with the Slovak Robin Hood!). As our windows won't need to opened (the ventilation system will ensure that we always have fresh air in the house), half of them don't open. However, as people expect to be able to open windows, every room has at least one window that can be opened! They are red on the outside and pine (to match the beams, etc) on the inside.

Around the same time that the windows went in, insulation was put around the bottom of the outer walls.

One of the den windows. Airtightness tape is covering all the spots where air could go in or out.

The neighbours are building a wall around their garden that we'll have to cover with bushs or some other kind of attractive cladding.

Close up of window and tape used to seal it in. The windows have also been screwed in.

Progress Mid September

2007-10-11T21:21:00.000-07:00

So much has happened over the past month that I haven't had time to update the blog! Here is a brief look at what happened in the first half of September. 8 September 2007: Thick cardboard cladding starts to go on the outside of the house.

11 September 2007: The interior walls have started to go up.

15 September 2007: Close up of cladding and guttering.

From 11-26 September the cellulose insulation was blown into the wall and roof cavities. This took a lot longer than expected, partly because of the number of cavities to fill, and partly because the machine wasn't stong enough to achieve the correct pressure. In the end it was done properly!

The cellulose pump.

Holes were cut into the walls (at intervals so that each cavity could be filled) in order to pump in the cellulose.

Alex, Adam and Emma in the play area.

15 September 2007: We have a cardboard box for a house!

28 August 2007 - Upstairs

2007-09-06T13:04:00.000-07:00

View from the footpath. There is no way of stopping Adam exploring!

Upstairs. Alex's bedroom and landing/den.

Upstairs. Master bedroom and study.

Boys' bedrooms.
Roof detail.

Roof Goes On

2007-09-02T12:37:00.000-07:00

In August the second floor has gone up and the roof has gone on. We have also sold our flat, so have the finances to continue! We have agreed with the buyers that we will move out by the end of October, so we will have to move into the house then, even if it is not finished!

Due to the summer holidays, everything has been progressing more slowly than we had hoped. On average, only two builders have been working on the site at any one time. In the next week or two the windows and doors should go in, the panels should go on the outside of the house, and the cellulose should be blown into the wall cavities. The water-tight shell will then be compete 23 August 2007: The roof tiles go on.
Adam is fascinated!

18 August 2007: The house is taking shape. The downstairs windows are those of the guest room; the upper left window is that of the main bathroom and the upper right that of the den.

11 August 2007: The roof frame will have cellulose blown into it for insulation.

11 August 2007: The front of the house. From left to right the windows at the top are those of the master bedroom, ensuite bathroom and main bathroom. On the ground floor are the kitchen window and front door.

11 August 2007: View of the roof from inside.

1 August 2007: The frame of the first floor and the base of the the roof are completed.

28 July 2007: The first floor is nearly finished.

19 July 2007 - The First Floor Goes Up

2007-07-28T13:49:00.000-07:00

In the hottest week since weather records began, and with temperatures reaching 40 degrees plus, the frame for the first floor went up. This was not a good week to be working on a building site!

Don't drop it!

Adam explores. The floors inside will be 30 centimetres above the current base.

Adam and the views from the living room windows. Unfortunately, more houses will be built on the plots next to ours.

At this point we went to the neighbours for a cool drink and for Alex to play in their pool!

Peter and the electricity meter.

20 July 2007: inside the house. The gap in the ceiling is where the staircase will go up. At the moment the beams are covered with OSB boards, so that the builders can work on the first floor. In the end they will be covered with nice planks of wood. Our nearest neighbours' house is visible out the back. Unfortunately, we couldn't afford to buy that plot as well.

15 and 16 July 2007 - Airtightness Tape and Beams

2007-07-26T13:56:00.000-07:00

The airtightness tape is an essential part of our passive house as it covers all the gaps and holes where air and moisture could seep in or out. It is really important that the house is as airtight as possible in order to stay warm in the winter. Generally, air moves via the cracks and crevices in the structure of any house because of temperature and pressure differences inside and outside. When warm air flows out via the holes, the heat flows out along with it. Also, cold air flows into the house via the same holes, thus cooling the house. So if a house has lots of holes, you need to pay more to heat it. Also, if there are lots of cracks in a structure, moisture enters it more easily, which also makes the house lose heat.

In a leaky house the air is exchanged naturally, which it must be to make the house habitable. In an airtight house, the same effect is provided artificially via an energy efficient ventilation system with a heat exchanger. The ventilation system forces the stale air out of the house via the heat exchanger, in which the incoming air is warmed up by taking energy from the outgoing air. Bjorn, the architect and project manager, rolling on tape.

Marian, the building contractor, cutting tape.

Zuzana, the architect, cutting tape.

The beams will remain visible.

The first beam is fitted over the taped-over holes.

The ground floor frame with beams in place.

Rudolf, the carpenter/builder and other builders slotting the beams into place.

Rudolf, the carpenter/builder. Also note the airtightness tape!

11 July 2007 - The Carpenter's Workshop

2007-07-26T13:45:00.000-07:00

The first floor and beams fill Rudolf the carpenter's workshop. Everything is prepared ready to be mounted on the site in just one or two days. Beams to separate the floors (on left).

First floor walls on the left and the outer wall beams with slots.

Alex climbing on a huge pile of sawdust.

More beams.

7 July 2007 - The Ground Floor

2007-07-26T12:39:00.000-07:00

We needed the ground floor in order to get an official valuation done for mortgage purposes. Building on the plot came to a standstill for a few weeks while we waited for the money to come in. Meanwhile, the carpenters were busy preparing the first floor and the beams and roof (see next post). View from the footpath that runs past our house.

Our roof tiles will be similar to the ones on the house through the window.

Holes drilled into the concrete to hold the screws connecting the frame to the foundations.

The base of the house.

The living room and terraces.

What are these metal pieces called?

21 June 2007 - The Calm After the Storm

2007-07-15T13:20:00.000-07:00

No sooner had the first walls been raised than a huge storm with gale force winds hit the area, bringing down trees and taking roofs off buildings! Emma drove out later in the evening to check that the walls were still standing, and took the beautiful rainbow arching over the hillside as a sign from God that all was well, which it was!

21 June 2007 - The First Walls Go Up!

2007-07-15T12:58:00.000-07:00

On a scorching hot day the team of architect, builders and carpenters put up the ground-floor frame. The pre-fabricated walls arrive by lorry.

Unloading the first wall.

Bjorn, the architect, (centre) discusses details with the windows and insulation people.

Marian, the building contractor, in the foreground.

Peter

The bolts and staples used to attach the frame to the foundations.

The Wooden Frame

2007-06-19T12:24:00.000-07:00

Our friend Marian has now been employed as our building contractor and his team of carpenters, led by Rudolf, are putting together the wooden frame of the house. They started at the beginning of June and these photos were taken on 16 June. Everything is happening really quickly now, and the skeletal frame should be ready to mount on the foundations on 21/22 June.

We will then be able to get an official valuation of the house (the walls will be more than one metre high!), transfer our flat mortgage to the house, and sell our flat to raise the cash for the next stages. We have found buyers for the flat who (if they don't pull out!) have agreed to pay straight away and let us stay in the flat until the end of September, so the house will have to be ready by then!

By the way, we have now come back round to the idea of having a heat pump to provide heat and hot water, and not solar panels! The heat pump can be connected to the 'Sole Kollektor' and the 'Sole-Luft Wärmetauscher' (official English translation welcome!). 270m of 3cm-wide tubes have already been installed 2.5, 1.8 and 1.1m deep in an 80cm-wide and 45m-long trench under the garden. An anti-freeze fluid will run through these tubes. We went a bit overboard, as 160m would have been enough, but we can always choose to connect up only two of the 90m long tubes. Bjorn is negotiating a good deal on the heat pump with an Austrian company, as our house will be the 'pilot project' in Slovakia.

Check out: http://en.wikipedia.org/wiki/Geothermal_heat_pump for more info

The first walls of our house and Adam in the workshop.
Alex the carpenter says, "Mummy, how long did you say I had to finish this jigsaw puzzle?"

The pieces of wood with the gaps and mesh have come from Germany and the rest from Slovakia.

Various pieces of the frame ready to be put together.

Adam and Alex carry out a quality control. Cellulose (recycled newspaper) 360mm thick will be blown into the walls during the final stage to provide insullation.

Alex looking through the windows.

Foundations Finished - March 2007

2007-06-19T11:44:00.000-07:00

We've had a bit of a break in postings due to technical reasons, as our home computer crashed with lots of photos on it and we haven't been able to recover the hard drive yet. Emma has also started a new job and has been very busy. Anyway, the foundations were finished in March 2007 and these photos were taken in April 2007. The West garden and base for SW terrace with pebbles. 270m of 3cm-wide tubes for the heating system have already been installed 2.5, 1.8 and 1.1m deep in an 80cm-wide and 45m-long trench under the garden.

The back garden and base for terrace with pebbles.

Most of the foundations with Adam, Emma and Alex and vineyards in the background. There is a good echo down the pipe!

Front garden, path and shed with detail of wall foundations.

The East garden and SE terrace (pebbled area). The mound of earth is where the carport will be and is being saved to make the clay 'plaster'. In front of it are the foundations for the main shed.

The East fence and garden from another angle. A cycle path runs under the row of trees in the background.

Finally, the photos you have all been waiting for!

2007-03-09T06:12:00.000-08:00

The land in January after it had been cleared of the vines, trees and bushes. The path on the right is the access road to the house behind our plot.

17th February 2007: Alex the builder, and other builders, laying the concrete bricks of the foundations. We are trying to do our bit to stop global warming by building a passive house, and global warming is helping us by providing the warmest winter on record.

The king of the castle!

View of the street.

19th February 2007: Visited site with Mum (Hazel). The concrete has been poured into the foundation walls.

3rd March 2007: The main concrete slab has been poured.The rectangles on the left and at the back are for the outside storage areas/work room. The left side from back to front will be the kitchen, hall, downstairs bathroom and kitchenette of guest room, the middle will be the dining room, stairs and guest room, and the other half of the middle and the right-hand side, including the jutting out bit, will be the living room.

Other news

Following discussions with Bjorn, and based on the results of his research, we are going to go for solar panels and an electric boiler to provide our hot water needs. The heat pump option would be more expensive and complicated.

Following negotiations with the bank, we are going to use the route below to finance the rest of the house:
a. borrow a lump sum immediately using Maria’s (Peter’s Mum’s) flat as collateral (she agrees!)
b. invest this money into the house, and then get a valuation done. Our current mortgage on our flat will then be switched to the (unfinished) house (this will ensure that we continue to receive the state benefit each month)
c. sell the flat and invest the proceeds in the house
d. get another mortgage on the house to cover any extra costs

Foundations Started

2007-02-16T08:51:00.000-08:00

On Wednesday we signed the contract with the builder who is doing the ground works. Holes for the foundations have been dug this week and the concrete may be being poured as I write. They are also putting in the pipes for the heat recovery / ventilation system. We are going to take some photos tomorrow. If the weather stays mild and dry all the ground works should be finished in two to three weeks’ time.

We are now trying to work out how we are going to finance the next stages. We should order the wooden construction and windows as soon as possible (and we need down payments for these). Once we have ordered them they will take six to eight weeks to arrive. Then the house can be built within a few weeks! In order to get a mortgage though, the walls need to be built to 1m above ground level. As our house is being pre-manufactured offsite, this is not going to be easy. We might have to persuade the land registry office (which will value the house with its “1m high walls”) that this criterion does not apply in our case. Peter has an investment fund that he may be able to borrow from, or we might have to sell the flat we are living in and rent a place for a few months if we just can’t get a mortgage at this stage!

Here are the contents of some recent e-mails from Bjorn. We will be discussing all the options and hopefully making some decisions on Sunday.

Some explanation as to the Zemný Výmeník (SOLE collector). Planned were 165 running meters of tube for pre-heating (winter) or cooling (summer) the air. I added another 100rm (it will be close to 300rm) to make it more effective, both winter and summer. In fact it is now long enough so that you theoretically could connect it to a heat pump (tepelné čerpadlo) up to 5KW. I made a calculation - such a heat pump would cost around 220 000.- including installation. But it would not be very reasonable to do so, because of the temperature gradient being too big (from about 1° to 55° for heating and warm water) the power ration (výkonové číslo) is only 3,2. (For 1KW el. you get 3,2 KW heat).

I now propose a different solution: Longer SOLE collector to boost passive gains (Winter and Summer) + larger solar panels (5 panels instead of 2) with cca. 10m2 + and direkt heating with electricity for the rest (el. spiral in solar heat tank). No pellet oven. Extra cost: 45 000 SOLE, 80 000 Solar. Saved money: 300 000 pellet oven + installation and exhaust pipe. The Solar panels will cover your need for hot water to about 68% and passive gains from the SOLE collector and especially solar collector will cover about 1/4 of your heating demand.

I calculated the need for electricity for 1 year for your house. You will need 1300KWh to heat hot running water during winter time, and about 2000 KWh to heat your house. All in all this is 3300 KWh per year for heating. Compared to that you need about another 4000KWh for all your other appliances (light, washing, cooking etc.). The price for you is 1,87 per KWh if you heat the house + 400 per month (tarif D11 from ZSE, 20hours a day, peak is more expensive, but you will not use that for heating). Because your heat losses are so small, heating directly with electricity makes sense.

Soon it will be possible to buy wind powered electricity (in Germany you can do that already) and it is probable that in 10 years time it will be feasible to mount photovoltaics for a reasonable price that will produce 3300KWh/a or more on your roof - this makes only sense if that gained electricity can be sold directly into the grid. This is possible in Germany and Austria today. This seems to me a sounder ecological strategy.

The pellet oven could save you the 3300KWh in electricity - but the price of the pellets would be comparable to the price of the electricity - and for the 4000KWh you need for other appliances you would get a higher tariff so effectively you would pay more. Failure of electricity: any power loss up to 24 hours will not change the inside temperature by more than 1°C.

There are small free standing ovens that burn bioethanol and produce only water vapor and CO2. These can be used for extra heating (up to 2KW) in passive houses. Bioethanol is expensive though, and is only meant for a once in a time use. These ovens are new and cost about 80000 SKK. I don´t think that would be necessary, I mention this only to inform you about possible back ups.

One more possibility:The heat pump is only slightly more expensive than the solar panels. So if we would skip the solar panels completely, we could replace them with the heat pump. With an overall need for heat of 7000KWh/a we would probably only need 2200KWh electricity, even less than with solar panels....life expectancy of a heat pump is a bit lower than solar panels, but the system is more compact and easier to install.

Finally, here is another website that is good if any of you in the UK want to make ecological changes to your homes: http://www.est.org.uk/ And it explains some of the things mentioned above.

The Story So Far

2007-01-25T07:34:00.000-08:00

Intro
This blog is going to record the building of our passive house near Bratislava, Slovakia. We have a bit of catching up to do, as work has already started.

The concept
We aim to build a passive house. It will be super energy efficient, with thick, air-tight walls and a heat recovery ventilation/heating system. It will not have any conventional central heating. We aim to have solar panels to heat water, which will be backed up by an electric boiler. The windows will be triple glazed and mainly south facing in order to catch the warmth of the sun. Shutters and the ventilation system will keep the house cool in the summer. We will provide links to websites and more information on these things in future posts.

Plot
We bought our plot of 550 square metres plus 50 metres of road in March 2005. It is next to overgrown vineyards and a field path leading up to the hills and down to the village. A walking/bike path goes from the bottom of the road up into the hills where it links up with a cross country skiing "loipe" and other walking paths.

Road and utilities
A local developer has built the road and connections to utilities. Work started on these in Summer 2005 and the last part of the road was finished in November 2006.

Architects
Our architects are Bjorn (Norwegian) and Zuzana (Slovak) Kierulf. They own the company Createrra.

Plans
Bjorn and Zuzana worked on the plans for several months. They finalised the outline drawings in December 2005, and the detailed plans were submitted to the planning authorities (town council - "Mestsky Urad") in July 2006. Various experts (water engineer, electrician, structual engineer, ventilation expert, fire inspector) also added their parts to the plans.

Planning permission
We had outline planning permission to build a house when we bought the plot. Final planning permission was given in November 2006. It is relatively easy to get planning permission for new houses on new estates in Slovakia. Any style of architecture seems to be acceptable, and every house can be different.

Ground works
Bjorn has found a builder (Pavol Kotul) to do the ground works. His team cleared the land of the old vines and tree just before Christmas 2006. Work is now starting on the foundations and the laying of the underground pipes for the heat recovery ventilation.

Photos and more details will follow soon. Here are some links for now:
http://en.wikipedia.org/wiki/Heat_recovery_ventilation
http://www.europeanpassivehouses.org/