FRANCAIS

beginnings
specification
site
modelling
changes
self build
ecological building

Energy consumption

Costs

design

progress ( # weeks)

latest photos 2012 - 13

160-200 summer/autumn 2011
122-160 Spring 2011
92-122 after moving in
91 moved in at last
90 stair, drive, rw drain
85-89 joinery, stair, more snow
81-84 help insulation snow
75-80 tiling painting snow
71-74 interiors and cistern
65-70 EDF problems etc
64 ground floor finishing
63 mezzanine finished
62 mezzanine finishings
61 joinery, painting
60 external final crépis
59 electrical connection
58 interiors mezzanine
57 external render (crépis)
56 plumbers back
49-55 kitchen garage doors
41-48 joinery floors etc
40 floors solar water heating
39 electrians plumbers
38 new year - help
37 garage tiled, heating on
36 roofing garage
35 mezzanine, tidying up around house
34 garage walls
33 floors, garage foundations
32 cladding, floors
31 grouting, cleaning
30 floor tiling
29 front door, tank, fireplace
28 stair, floor framing
27 pipes, screeds
26 underfloor heating
25 chimney, flue
24 more self build
23 masons, septic tank
22 new machine
21 plastering
17- 20 electricity, insulation
16 last windows
15 self-build again
14 first windows fitted
13 self build, details
12 external cladding
11 purlins and roof tiling
10 erection of frames
9 making trusses
8 ring beam
7 monomur walls
6 floor beams
5 basement walls and monomur
4 crane
3 ground slab
2 foundations
1 earthworks

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Building a solar house in France is a challenge, even for an architect, and beginning another self-build project at the age of 72 is a bit of a challenge too. This is a picture record - a plog rather than a blog - a series of 'albums' of annotated drawings and photographs, following the progress of the project, from its inception to completion, recording the setbacks, the frustrations, the rewards, the delays, the changes of direction, the incidents and accidents along the way.

beginnings

The project began in 2000, after a terrible hurricane that swept through this part of France leaving devastated forests, smashed electricity pylons and telephone lines, blocked roads and railway lines and damaged buildings and infrastructure. We were without electricity, water, and telephones for weeks. We decided then to build a new bioclimatic house that would be as self-sufficient as possible.

background

I had spent 18 years since the first energy crisis in the 70's, doing research into low energy and passive solar building at Sheffield University, and designing bioclimatic houses for myself and others. After that period, during the 90's, I was bitterly disappointed that those early concerns about ecology were forgotten as energy became cheaper and Western economies rushed ahead to consume more and more, producing increasing amounts of waste and pollution. Politicians rubbished the warnings of scientists and ecologists that the earth's atmosphere was becoming dangerously overheated by overconsumption of fossil fuels, destruction of forests, leading to climate change and, probably even more drastic in its effect on our way of life, the imminent exhaustion of the fossil fuels that have made a heavily mechanised, technological and enormously mobile way of life possible. The hurricane and its aftermath was an immediate and vivid illustration of climate change, and we decided to invest all our resources and energies in making a tiny personal contribution, by changing our way of life and expressing it in doing what I knew most about - building a house. Of course there was a selfish element, because I believed that soon the international competition for the diminishing resources of oil and gas would lead to soaring prices for fuels. This was confirmed by the rise of the oil price in mid 2008.

programme

The specification for our new house evolved slowly based on our experience of living here for 15 years in a farmhouse that we had restored. Bioclimatic architecture is based on an understanding of the local microclimate, and a study of the way that traditional buildings in the region responded to it. In addition I had become much more aware of wider ecological, health and environmental considerations, and their impacts on building design. So our requirements were for a compact house with very well insulated exterior surfaces, windows open to the winter sun but shuttered and shaded in summer, and built using locally grown timber and natural materials. Its heating would be by a wood-burning high efficiency boiler/stove. Because of the increasing frequency of severe heat waves in summer brought on by climate change, it would be naturally cooled by burying part of the house in the earth, and having a lot of internal thermal mass and insulation. I wanted to avoid any high-tech solutions for heating or cooling. The only serious concession to technology would be solar photovoltaic collectors to contribute electricity to the grid to offset our own needs, and flat plate solar collectors to heat water for domestic use. In addition we planned to collect all the water from the roof in a large cistern for domestic (filtered for washing machine and to flush toilets) and garden use.

site

The search for a suitable site took 2 years. It had to be within cycling or walking distance of a local market and shops. We wanted about 4000 square metres with a lot of trees and the right orientation to benefit from direct passive solar gain, and solar collectors on the roof. When we found one that seemed to be ideal, and applied for planning permission, there were restrictions imposed on the size of house that could be built on it. We eventually found one nearby, 4 kilometres east of Brantôme, with permission to build a slightly larger house. We bought it in 2003 and started planning. the rest of the story is in the annotated picture albums.....

design modelling

At first, having been working as a artist and printmaker for 15 years with very little architectural work to do, I reverted to my drawing board, 'T' square and Rapidograph, and simple rule of thumb thermal design. But as the need to test designs increased, I reverted to using my computer. I had to upgrade to use an up-to-date CAD system (TurboCAD and ArchiCAD). And luckily the SPIEL dynamic thermal modelling program that I had developed in the 80's, still worked with Microsoft Windows XP, despite having been written to work under DOS before Windows ever existed. It is the only good mark I can give Microsoft - the fact that they have always supported DOS programs - and long may it last ! Spiel was financed partly by the European Community and the Region of Lombardy in Italy, through the Ispra Solar Energy Laboratory. Modelling with SPIEL was done for every little change that affected thermal performance, like changes in insulation, amount of glazing, heating system, controls of heating. The aim was always to acheive the minimum energy consumption in winter and summer and avoid overheating in summer.

SPIEL calculates temperatures in up to 25 zones every hour, throughout a year, calculating the solar gain absorbed through every window, the amount of heating put in to each zone, according to the type of heating system, fuel, thermostatic control used (or none). It takes account of heat from occupants, from lighting, heat from cooking, hot water use and equipment. It calculates the heatloss of every wall, floor, roof and window, the heat lost by ventilation or infiltration, and the amount of heat stored in every element of the building. From all this generated and calculated data it summarises the overall consumption of the building for a year or for a given day or period. The program can be used to size the radiators, or show the hour by hour temperatures in any zone on any day, for given exterior weather conditions of sun and temperature. It can be used to check confort in summer and the effect of blinds or shading.
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design changes

The problem with building an ecological house at this particular time is that since I began the project, the level of interest in the idea has grown enormously, stimulated by worries about global warming, about energy, about health and avoiding toxic materials etc. As a consequence there are a lot of publications in France devoted to the subject - the magazine Maison Ecologique is the best example. New materials are being evaluated, or introduced without evaluation. Tax credits are being proposed or changed. As the house was being designed, and even while it is being built, I have had to consider new information and better options all the time, which have impacts on the design. Luckily I am simultaneously client, architect and project manager, and using a CAD system like ArchiCAD allows me to make changes very quickly and easily (sometimes too easily). Also the building industry in France is booming and builders have to be booked up so long in advance, that changes are inevitable by the time they come to do the work.

I had intended to build a house entirely in timber (over the basement) but could not find a local builder to give me an affordable price for the kind of construction I had designed. I had built about 18 houses in Britain using post and beam construction with bolted connectors, with infill framing and timber cladding. Local carpenters here are used to making frames and trusses of quite massive sections with mortice and tenon joints, and were not keen to change their ways. So paradoxically, the prices I was given for doing traditional construction using green oak were less than for using smaller sections in Douglas Fir with bolted connections. The local forests are mostly of oak and chestnut, and slightly further north, there are large areas of douglas fir and larch.

Bioclimatic architecture is founded on the idea of emulating the traditional wisdom of vernacular architecture, and trying to use local materials and methods. So I was quite happy to make the changes to use green oak frames and trusses made in the traditional way, especially as it saved us money ! I had already decided to use Monomur fired clay blocks for exterior walls for their thermal properties in very hot summer conditions, so the design had to change to accommodate these.
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self build

The words 'self build' mean many different things, from the owner doing everything himself - digging the foundations, mixing the concrete, constructing the walls, roof and interiors and even doing the plumbing and services. Very few can acheive this level of self build today, and it takes many years to build a house single handed. A few can build a house more rapidly from a kit of parts pre-assembled in a factory. I helped to form, and was part of a cooperative group of 14 families who built a group of solar houses in Sheffield (UK) in the early 80's, where the whole group covered a range of building skills, and all cooperated to build one house at a time, taking just 3 years to complete the 14 houses. (See Paxton Court - Sheffield Solar Building Cooperative).

' Self build' is more often used to mean the owner commissioning and organising the construction of his or her own house, often not lifting a finger or dirtying hands. I think that this is not really self-build at all. My age (now 74) means that I am not able to do everything I did when I was younger, but I am determined to do as much as I can. In this case, (helped by my wife Margaret and family) I am doing most of the interior timber framing, partitions, joinery, painting, and all those little tedious things like cleaning up and making ready between the workmen, tradesmen and craftsmen who we are employing to do things that we cannot do. We have a 25 year old Renault Trafic van, a concrete mixer, scaffolding and have had to buy more tools and equipment in the course of the project. We buy and collect timber direct from sawmills and other materials and components direct from suppliers, which gives us more flexiblity to shop around, finding bargains and saving money.

There is a profound feeling of satisfaction in designing and building one's own house, which makes all the backache, frustrations, delays, and crises worth while in the end. Not least in value are the cost savings that result from this type of self build (see cost analysis later).
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Ecological Building

The project has been dominated by the idea of bioclimatic design - to design a building in harmony with its local natural environment and microclimate, using locally sourced natural materials and passive solar gain to augment the heating. But in addition, the impending crises of fossil fuel resource exhaustion, climate change and rising carbon emissions, have been at the forefront of the reasons for design decisions. So, choices of materials and construction are weighted in favour of long term energy conservation, and the use of renewable fuel resources. So domestic water heating is from solar panels, underfloor heating and radiators are from a wood fired boiler with 1000 lire storage buffer tank. Later on, electricity will be generated by photovoltaic panels.

After this, in priority, comes the use of renewable local materials. As much as possible of the house is built using locally grown timber from sustainable forests - chestnut (windows, floors, and horizontal internal cladding (lambris), larch (external cladding), Douglas fir (rafters,purlins, all timber framing for partitions and floor joists), oak (main structural frame and trusses, staircase, some floor boards (parquet)), acacia (floors in bathroom), poplar (ceilings and some floor boards). Some internal doors and joinery are in birch.
All the internal partitions are in woodfibre and gypsum compressed panels ("Fermacell") which are imported from Germany. The only other imported material are ceramics floor tiles from Italy or Spain. Some kitchen and bathroom fittings are also imported from northern European countries.

The next priority is the avoidance of toxic or noxious chemicals, adhesives, materials, treatments, paints and stains. The only wood treatment used was borax solution. All the timber used was naturally resistant to insects and fungus - larch, acacia, chestnut, oak, poplar and douglas fir. All paints were water based and certified safe to use. Walls were lime based with casein and natural earth pigments (badigeon).

Then comes consideration of energy-using processes and transport of materials and labour, It is impossible to avoid the use of machines to move heavy materials, but this happens over very short periods compared with the life of the building. The use of a crane, even on a single house, saves an enormous amount of energy - only 36 kWh was used to move and place all the heavy masonry and concrete. It is also impossible to build a heavy partly earth-sheltered building without using some concrete, or concrete blocks. Where contractors were used, they were locally based. We transported all self-build materials in our small van, because we found that often small quantities were delivered in large lorries.

Similarly it is impossible to build without using some materials like plastics which have a petrochemical origin, but their use to save energy in a building which will last perhaps over a hundred years, greatly outweighs their embodied energy, or the fact that they are not biodegradable. Much of the plumbing and electrical installation cannot be done now without PER tubing and plastic conduits. The current price of copper precludes its use throughout. And there are serious ecological and social problems in copper mining countries!

Far from the least important consideration is the use of rainwater collected from the roof in a 4000 litre cistern, and used to flush toilets, garden and filtered and purified to wash clothes.

Energy Consumption

The following analysis is based on 3 winters of occupation, 2 of which were classed as severe, with record low temperatures and low sunshine hours. The house was comfortable through all conditions, even when the outside temperature went down to -16 degrees. The wood used was a mixture of Chestnut, Oak, and wood gleaned and cut on site. The electricity used for backup heating of the storage tank was on the off-peak tarif.

Habitable area of House and Studio = 242 msq

Average wood for insert boiler = 6 stères (approx. 3000 kg.)
Electricity equivalent produced = 6900 kwh
Additional off peak electricity = 2324 kwh
Total = 9224 kwh ; heating per unit area = 38 kwh/msq.

Electricity backup for solar water in winter = 508 kwh
Heating per unit area = 2.1 kwh/msq

Domestic cooking, lighting, and electrical appliances = 2682 kwh
Heating per unit area = 11.1 kwh/msq

Costs

The following table gives a detailed breakdown of the costs which were very carefully monitored by Margaret. We obtained at least 2 competitive tenders from every tradesman or enterprise doing work that I could not do myself. Most estimates were based on a specification and quantities that I provided. At the end the final quantities were recalculated. Materials for my self build work are all lumped together, but did not include the capital costs of power tools I bought for the job..

Note the cost per square metre = 983 €/msq

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