1. Eing
2. What is ecological or sustainable building?
3. The state of ecological building
4. Money is available
5. Construction cost considerations in general
6. Life cycle assessment/ Life cycle assessments
7. External costs
8. On the Sense and Nonsense of Inexpensive Ecological Building
9. Where is ecological building more expensive and why?
10. Summary of results of studies and review literature on the topic of "low-cost ecological building":
11. Examples of low-cost ecologically realised projects
12. Principles for ecologically cost-effective construction
13. Building cost considerations using the example of
14. Outlook
15. Task of the universities
16. Download
17. Literature "inexpensive ecological construction

2 What is ecological or sustainable building?

Ecological building: Basically, building + living will always be an ecological burden. Building will always interfere with and disturb ecological systems. This is not a problem as long as the resources can be regenerated and the residual and waste materials can be returned to the biosphere without any problems. This is called consistency.

Sustainable building includes social and economic aspects in addition to the ecological approach. Ultimately, it is people and their lifestyles that strongly influence the environment. Only with their agreement and cooperation can sustainable developments be achieved and implemented on a large scale.

The main focus of building biology is human health. Human health is not merely the absence of disease and infirmity, but a "state of complete physical, mental and social well-being".

Old building
At the moment, about 450,000 new buildings are constructed every year, 100,000 of which replace old buildings. If all new buildings were constructed "super-ecologically", it would take about 100 years to replace the 35 million old buildings in Germany. Therefore, the old building stock must be ecologically renovated. Almost all houses currently built are still built conventionally. New "old building stock" is constantly being produced. In order not to lag behind developments, it is first necessary to ensure that new buildings are constructed according to ecological criteria.

If new construction, then as environmentally compatible as possible
If one builds, then the most environmentally friendly, energy- and resource-saving variant should be chosen in as many areas as possible. A material cycle analysis (life cycle assessment) can provide information on this, which not only looks at the energy and resource consumption of the building in operation, but also includes the construction and demolition of the buildings.

Good architecture and urban planning is ecological and economical in approach
E.g. space-saving floor plans: every square metre of living space saved reduces the consumption of materials and resources and lowers construction costs by approx. 1,000 to 1,500 euros/sqm.
The economical use of building land is ecological and economical. A GFZ of 0.8-0.9 is a good compromise between high quality of stay, dense building and the requirements of ecological open space design.

Ecological building in keywords

• Space-saving construction
• Climate protection concept through CO2 avoidance in the areas of construction, housing, transport and commerce
• Use of renewable energies
• Resource-efficient construction
• globally recyclable renewable materials
• the use of regional building materials strengthens the local economy and reduces traffic
• Healthy living, building biology materials
• Avoidance of problematic materials such as hazardous waste
• Decentralised wastewater concept/rainwater infiltration
• Biotope networking
• Creating references and opportunities for experience with the elemental and the "invisible", such as "water", earth, plants, animals, energy, waste ...
• Stimulation of the senses through materials that are as natural as possible

3. the state of ecological building

State of the ecological building materials market
"In hardly any other market is the discrepancy between the importance of a topic and corresponding market shares as great as in relation to ecological products". Of the total turnover of the construction volume (275 billion €), building materials account for (75 billion €) of which 0.2-0.3 % (175 million €) are ecological products. There are about 1,800 conventional building material stores and 8,000 building material dealers and only about 200 organic building material dealers. [DIW Berlin; öko+ Karlsruhe 1996].
Since the "big players" have also recognised the growing demand in the eco-building materials sector (depending on the survey, 20 - 50 % state in surveys that they attach importance to environmental and health aspects in building materials and also spend more money on them [Hannoversche Allgemeine 25.10.97 survey of a building society], the conventional building materials markets are reacting. For example, in the last few years the first new organic departments have been opened in conventional building material markets, e.g. HORNUNG in Stutensee. NOVEBAU (Aurich), RAAB KARCHER, OBI and HAGEBAU are also planning to open organic departments or organic building material markets [öko+ Pressemappe 1996].

4. money is available

Germany is the 7th richest country in terms of gross national product (1988) after Switzerland, Japan, the USA, Finland, Sweden and Norway [World Bank 1990, 211; Qu.: p.111, Verel.d.Naturz.].German private households saved almost two trillion Euros in 1993. If this money were evenly distributed, each German citizen would have approximately 55,000 Euros on the high side.
95% of the total saved financial assets are in the hands of the "Wessis" [Globus].

Investment priorities
Money is available, e.g. for nuclear energy, fusion research, space travel, armaments. And here, there is no licking of the chops, but rather a lot of bungling. For example, a Castor nuclear waste transport from La Hague to Gorleben cost 28 million euros for safety measures. This money could have been used to build around 4,000 solar systems for 4-5 person households, which would then have provided free and environmentally friendly heat for 15 to 20 years.

Thinking priorities
The prioritisation in the field of knowledge is similar: the intelligence of our engineers and scientists is invested in even faster cars and their aerodynamically erotic door handles and the like. The people working on the 5 questions of the future mentioned in the introduction are frighteningly few. Even the universities are not living up to their role as thought leaders here.

The question of economic efficiency
Sometimes one wonders how it is that some questions such as "how profitable is the installation of a kitchen, and is the kitchen more economical if it costs 2,500 euros or 10,000 euros, or why is a garage necessary for 10,000 euros?" are not asked, but instead the shortest possible payback period is to be proven for every cent of additional costs for ecological building materials or techniques. Here, we should first ask ourselves the fundamental question of whether our value system is still correct, and whether our demand for comfort should not first be defined, which now already differs considerably from the status 50 years ago and that of other regions of the world.

Economics of Housing: City or Country?
A 300 sqm plot of land, in a normal residential location, costs an average of 78,000 euros in the city (260 euros/sqm, as of April 1995). Approximately 40 km outside the city limits, the square metre costs only an estimated 150 euros. The buyer therefore only has to pay 45,000 euros for 300 square metres, saving 33,000 euros on the purchase of the land. If the buyer is dependent on a car to get to his workplace 40 km away, the monthly travel costs for a medium-sized car are about 235 euros. If these costs are extrapolated over 20 years, the driver pays about 57,000 euros for the car. The savings effect on the property is already reduced to zero in the 12th year, and in 20 years there are additional costs of about 24,000 euros.

EU study "City without car": 50- 80% costs can be saved
What it means for an entire city to rely on mobility without a car was published in a study "Citta senz'auto" (City without a car) by the European Community in 1992. In it, it was calculated for different city sizes how the costs of a city that organises mobility entirely with public transport relate to the costs resulting from the usual organisation of mobility with public transport and cars. The result is striking: depending on the scale, the mobility costs of cities that rely entirely on public transport are between 50 % and 20 % of the costs of cities whose mobility is based simultaneously on public and car transport. This is only a model calculation, which has one problem: in addition to the public investment and maintenance expenditure for the various transport systems, the calculations also include the costs for private passenger cars (purchase price, maintenance, taxes,...), i.e. the expenditure of private consumption, (which in real terms is not paid for by the public sector) [T. Krämer-Badoni "Stadtquartiere ohne Autos" p.4].

5. building cost considerations in general

Comparisons of construction costs are very difficult to make, as not all factors for the development of a price are usually known. The following is a sample of how much the total construction costs differ regionally and in which areas there is great potential for savings.

When looking at the total costs of a study on a residential and commercial construction project, the high shares for management, financing, developer and distribution are particularly striking. In total 31%. Thus, if significant savings are to be considered in our construction operations, thought must inevitably be given to task and risk allocation, contract design and execution times [p. 190 (4)].

Furthermore, greater cost reductions can be achieved in the economical use of building land than in saving on the quality of building materials. On average, about 25% of the construction sum goes into the land. Regional price differences can also be much more decisive for the total costs. For comparison: one square metre of building land costs
in Stuttgart: 750 euros
in Karlsruhe: 275 €
in Bremen: 95 €
[imu, Stuttgarter Zeitung No.143]

Housing costs can also vary from region to region: A 3-room apartment with 70 sqm and medium housing value cost on average in 1997:
Düsseldorf: 158,000 € (approx. 2,250 €/sqm WF)
Stuttgart: 115,500 € (approx. 1,650 €/sqm WF)
Brunswick: 84,000 € (approx. 1,200 €/sqm WF)
[imu, Stuttgarter Zeitung No.143]

Which construction costs are meant?
It should also be noted that most publications do not specify which building costs are meant. With or without land? Gross or net? With basement or from the top edge of the basement (in prefabricated house construction, for example), ... etc. In this text, I include these details as far as they were given in the source texts.

Reducing construction costs through new robot technologies?
The construction robots known so far from Japan are only capable of erecting high-rise buildings from prefabricated steel girders. Economic efficiency is only given when more than 50-60 storeys are erected. For the sake of good order, it should be pointed out that these are also only prototypes, although they have already built houses. However, according to experts, the share of robot work in the total building is only 15%. [S.50 (3)]

6. life cycle assessment / life cycle assessments

As Holger König explained in the magazine Gesundes Bauen und Wohnen 60/1996, p.36 ff, an ecological and cost balance should be based on a complete product line analysis, which includes the formation of substances (extraction, production), the use of substances (processing, utilisation) and the dissolution of substances (disposal, recycling), extended by the aspects of the environment of a building.
Decisive for an ecological and economical construction method is first and foremost the economical use of building materials or the reduction of the amount of materials to the necessary minimum and secondly the choice of materials. The combination and appropriate joints (profile) of ecologically favourable building materials are decisive for the overall result. The longer the durability of building materials can be assumed within their joints to building structures and no durable materials have to be destroyed in order to replace less durable ones, the overall ecological payback period of buildings is extended. An important element in determining the ecological payback period is the depreciation periods of the materials also from an economic point of view. If the durability of the building structure is used in parallel with the depreciation periods, the cost differences of the various ecologically favourable variants hardly matter.

E.g. disposal costs
Rough model calculations have shown that, for example, in a larger building project of about 20,000 m3 of enclosed space, about 40 to 50 waste containers with a total of 400 m3 of waste would be disposed of, which would cost almost € 35,000 in landfill fees in Frankfurt, for example, without sorting and avoidance. With a waste reduction of 25% and recycling-sorted disposal, these costs could be reduced to less than 10,000 €, i.e. about 25,000 € can be saved. The effort for waste prevention and sorting was calculated according to practical experience with costs between 10,000 and 20,000 €. This means that the effort is offset or even far exceeded by the landfill cost savings [p.220 (4)].

In the following assessment programmes, cost and life cycle assessment considerations are balanced:
=> BauBioDataBank
of ECOHB (European Cooperation of Organisations for Healthy Building and Housing).
=> Ecopro, developed by Prof. Kohler/ ifib (Institute for Industrial Building Production), University of Karlsruhe together with Holger König/ öko+ Fachhandelsverband für Ökologie- und Bautechnik, among others.
=> LEGEP, Life cycle of buildings from an ecological point of view

7. external costs

The Fraunhofer Institute ISI in Karlsruhe has calculated for the year 1993 that the external costs caused by the entire production of goods in the Federal Republic of Germany amount to approx. 305 billion €, which corresponds to approx. 20% of the gross national product. If one just sticks to the figures, each product could cost 20% more and would still be cost-neutral if it did not cause any more external (social or ecological) costs. Expenditures to eliminate the (environmental) damage are, as experience shows, always more expensive than the amount of damage [p.28 (4)]. After all, in its current 3rd Building Damage Report, the Federal Government calculates annual economic losses of several billion € [p. 78 (1)].
And even chief economist of the Deutsche Bank, Norbert Walter comes to the assessment in the Handelsblatt on 23.4.1996: "Our ecological debt account is overdrawn, and we don't notice it because we don't balance our future."

External costs that have to be borne by the general public are, for example:
* Insurance: e.g. healthcare
* Risk insurance for industry
* Pollution of air, water, soil
* e.g. tanker accident
* Drinking water production (complex water treatment)
* Building damage due to air pollutants
* Sick leave,...

It seems that the value of nature and environmental goods is not recognised. Or as Binswanger [1979, 170] comments: "It was as if the soil, and with it nature in general, had been put on a cloak of invisibility. [p.99, Impoverishment through the Destruction of Nature]

Various calculation methods are used to try to internalise or monetarise such external (social, ecological) costs:
GEMIS 2.0 Calculates external costs caused by air pollutants and greenhouse gases.
E.g. one tonne of CO2 causes € 25 external costs, or 1 tonne of SO2 € 2,500.
Developed by IWU Darmstadt +GhKassel; free of charge on the Internet
Each car is subsidised by the general public with 3,000 € per year. This means that road traffic creates a bigger debt hole in the national budget than the Federal Railways. [nature 3/ 91 p.70 Study by the Heidelberg Environment and Forecasting Institute (UPI)].
External costs also include the use of building materials that are harmful to health. The costs of illness are paid by the general public (health insurance) and not by the actual polluter, the producer of the building material. Only a few building materials have been tested for their harmlessness to health. Only in the case of scandals such as "lindane, PCB, formaldehyde, asbestos,..." are health compatibility tests carried out. This is, among other things, a general problem of product liability in Germany.
Limits of monetisation: Many things can only be monetised inadequately or not at all: how much is the experience of nature itself worth? Or what is the cost of the extinction of an animal or plant species? These are ethical questions that cannot be solved satisfactorily in monetary terms.
Ecological tax reform as an incentive for ecological building
An ecological tax reform - making energy and resource consumption more expensive, reducing labour costs and abolishing VAT - would be a decisive contribution to massively promoting environmentally friendly construction methods already today. The increase in the cost of transport energy, for example, encourages building with regionally available materials. As labour becomes cheaper and materials more expensive, incentives are created to replace materials with intelligence, and so on.

8 On the Sense and Nonsense of Inexpensive Ecological Construction

The lifestyle issue is not to be sneezed at: the architect turns over every penny in the planning so that the client can afford a second holiday in Tenerife. This is not within the planner's sphere of influence, but the result is paradoxical. The ventilation behaviour of the occupants can be decisive. In low-energy houses of identical construction, incorrect ventilation behaviour can cause twice as much energy consumption. The way the technology is handled is often more decisive than another 2% increase in efficiency through a more expensive heating system.

Why build cost-effectively?
For social development, i.e. in terms of global politics, it will be necessary to build cheaply. Only then will an ecological or sustainable lifestyle be able to prevail among the masses. The current Western model of prosperity cannot be applied to the entire world population. Imagine that every second Chinese, like us Germans, has a car. So many cars could not be built. There are not that many resources. But this is exactly the resource-intensive lifestyle that the majority of humanity is striving for. We industrialised countries are therefore responsible for developing a sustainable model of prosperity and setting an example. A model of prosperity that can be copied without any problem (or not.) It is better to have an independent regional development and to preserve our own identity), and which preserves our livelihoods.

Ecological housing and urban development can educate people to act ecologically, at least not directly. But they can create the framework for living such a lifestyle.
The money saved through low-cost construction can be invested elsewhere. In a self-help project in Guayaquil/Ecuador, for example, one can build a house for 296 € [db 2/ 95, p.78]. This may make a greater ecological and above all social contribution than the somewhat more optimised super eco-house in Germany. However, we are still light years away from such thinking and acting.

Discussion of common claims
1 The general statements that ecological building is not more expensive than conventional building standards or that it is more expensive in any case - depending on the ideology - are therefore both untenable. Here, a more objective discussion is required, which must be based on carefully prepared facts regarding the assessment of building elements and their individual costs [p. 69 (1)].

2) That ecological building is three times as expensive as conventional methods, as is repeatedly claimed, is simply wrong. Expensive demonstration projects, such as the energy self-sufficient solar house (approx. 750,000 €, half of which for the solar hydrogen technology alone) or the experimental house "Heliotrop" (costs: approx. 450,000 € for 91 sqm of living space and 117 sqm of workrooms) in Freiburg by Rolf Disch, have a high degree of publicity, but are the exception. The model character justifies the high costs.

3 Despite repeated claims to the contrary, it can be stated that our current ecological knowledge is more than sufficient to decide on a sufficiently differentiated ecological target system at the level of a city. The claim that ecology as a science is not yet ready is simply wrong. Much more is known today about ecological interrelationships than about many other policy areas. What is important is the will to adopt ecological goals politically and normatively and to endow them with a binding force that goes beyond the day [Zukunft Stadt 2000, p. 371, Wüstenrot Stiftung Deutscher Eigenheimverein e.V.; documentation and summary of an expert conference held by the German government in 1992 and 6 expert reports commissioned by the Wüstenrot Foundation].

9. where is ecological building more expensive and why?

* People can often afford to build expensively. This leads to the conclusion that ecological building is generally more expensive. Exaggerated standard expectations among builders and planners
* little experience on the part of the planners and craftsmen
* higher planning costs that are not remunerated (HOAI)
* lack of standards
* Ecological building materials are still partly more expensive due to low production volumes
* Production of ecological technologies more expensive
* Green roofs: constructive additional expenditure
* Double piping system for domestic/drinking water
* more insulation measures
* Winter gardens for passive solar energy use are expensive and cannot be justified by energy-saving aspects alone.
* Certification of building materials, e.g. "öko+", is an additional expense.

Barriers to green building
* About 65% of all German citizens surveyed confessed that they were insufficiently informed about the many possibilities of environmentally friendly building.
* In general, changes in the economic, legal and organisational framework are necessary to reduce costs in housing construction. Proposals for this are detailed on page 127 in (9).
* "There is still a lack of ecologically thinking and planning architects, of craftsmen who can apply the appropriate building techniques, of specialist engineers and of municipalities that designate building areas with ecological specifications." [S. 270 (7)].

Interim conclusion: Low-cost ecological building
As I discovered in the course of my research, the topic of low-cost ecological building has been dealt with very extensively. Various comparative studies and overview literature on realised projects provide a good overview of the topic. I summarise the most important statements below.

10. summary of results of studies and review literature on the topic of "low-cost ecological building":

"Ecological & Economic Building in Practice." Proceedings Ecobuilding Congress 1996 (see literature source 1)
This conference volume publishes a study by the Landesinstitut für Bauwesen, Aachen, (commissioned by the NRW Ministry of Building and Housing), which compares various projects in ecological and low-cost building funded by the state of NRW. For the data, construction cost values of about 25 projects were determined, selected as examples from the total volume of more than 100 projects. "From the empirical values listed, the tendency can be read that it is possible to significantly reduce the usual construction cost framework even in environmentally sound construction." [p.69 f] The above-mentioned eco-building congress was organised and moderated by the Öko-Bau Institut für ökologisches & wirtschaftliches Bauen, Krefeld. It has many years of experience with ecological planning for new buildings, conversions and urban development and writes: "Experience teaches us that the costs of ecological projects can compete with those of conventional building. The construction costs are the same, despite higher quality. ... The greatest economic advantages of ecological building lie in the use and follow-up costs. The more consistently the principles of ecological building are implemented, the more can be saved in these areas". (see literature source 2)

Conference Proceedings "Cost-Effective Ecological Planning and Building"
(Literature source 3): "There are enough examples of projects that stand out not only because of their low costs but also because of their high ecological quality." Dr. Michael Vesper, Minister for Building and Housing NRW (p.14)
This conference volume contains a report on the results of the research commission of the state of NRW "New solutions for low-cost housing in NRW" (p.77 ff). "The subject matter is housing projects that remain below the cost ceiling of 900 €/sqm living space. A remarkable result of this research is that in examples of multi-storey housing the pure construction costs are not higher in the projects that have many ecological measures than in the projects with lower ecological quality. And what I find even more interesting is the result that projects with a very small proportion of ecological measures did not hold their own so well in internal cost competition. So it is possible to build ecologically and at the same time to build cost-effectively." (S.14)
"The impression is that ecologically motivated planning also achieves more rational and therefore perhaps more cost-effective results than conventional building." (S.83)

"Die Wirtschaftlichkeit des Ökologischen Bauens" (The Economics of Ecological Building), conference proceedings for "terra-bau" 1995 in Hanover (see literature source 4)
"In recent years, many measures of ecological building have been refined and optimised. Measures and models have been developed that attempt to reduce the cost factor. This congress will demonstrate whether and how this is possible and what needs to be paid special attention to with the help of many practical examples. It will be shown in which areas the use of new technologies makes sense in order to make a cost reduction possible in the context of ecological building, but also where these technologies still need to be further developed". (S.1)"What always amazes me a little is the persistence, at least in Germany, of the prejudice that cost-effective and ecological building are opposites. We know that this statement is simply wrong - at least as a general rule. ... Once this is clear, all we really need to do is convince the many sceptics". (S. 107)

Study "Ecological settlement (re)construction (see literature source 5)
Chapter: Cost and benefit analyses
As experience with the "Waldquelle" housing estate in Bielefeld shows, there is always a positive economic result from about 100 housing units upwards if investment is made in decentralised self-supply on a large plot by reducing the development costs." [p.7, ch.VIII (5) ]Chapter: Implementation of decentralised systems
In this chapter, decentralised ecological settlement concepts are compared with conventional ones. The figures of the ecological settlement "Waldquelle" and a planned settlement in Hamm-Heessen were used as study projects. Waldquelle" settlement and a planned settlement in Hamm-Heessen were used as study projects. The following values result from the comparison of energy costs:Consideration of investment costs: The cheapest variant is the own supply and disposal on the large plot by CHP with 1,534 € per m2 living space, the second cheapest is the own supply and disposal on the large plot by solar heat with 1,674 €/ m2 living space. Only then comes the now common public supply and disposal with 1,781 €/sqm living space on the individual plot and 3,594.-Dm/sqm living space on the large plot. In economic terms, the single owner in the Hamm region, who has to pay an average of 1,874 €/sqm of living space and a maximum of 2,234 €/sqm of living space for a conventional semi-detached house, is completely inferior.Consideration of the operating costs: For the occupants of a semi-detached house connected to the self-supply system, the use of solar heat on the large plot already results in cost savings of around 1,042 € per year in operating and ancillary costs at the time of the start of use. If a holistic cost analysis - which includes investment and operating costs - is carried out, it becomes apparent that the number of annual rents to cover the investment costs is reached about 7 years earlier in the case of self-supply with solar heat than in the case of public supply. [The greatest challenge for the preparation and implementation of further projects is the high level of discussion and communication between all project participants. The holistic approach of the project must be included in the preparation as well as in the execution of the task (qualities, quantities, costs and deadlines), so that the success of the economic and financially viable concept can be guaranteed.

Study "Forward-looking ecological settlement construction in Europe - a report on experience". (see literature source 6)
In this study, ecological settlements in Europe were compared and their experiences documented. The following is stated about the construction costs:Due to the regionally very different price levels, the different vintages and construction concepts, the construction costs per m2 of living space cannot be compared in a meaningful way. However, a trend can be observed:
- the more technology, the higher the investment costs,
- the more technology, the higher the follow-up costs,
- Use of local resources and conditions reduces costs,
- numerous ecological aspects are available at no extra cost
- A lot of things that are more expensive or take longer at the beginning pay off in the long run,
- The image gain for cities, developers and architects through the realisation of ecological housing estates is priceless! As the example of "Puchenau" (750 dwelling units) shows, many fundamental goals and principles of ecological urban development can be implemented without additional financial expenditure compared to conventional urban development. But the implementation of more far-reaching goals also seems possible within a cost framework that allows for ecological housing development on a larger scale in social housing. In almost all projects, however, "high ecological goals" and the higher costs associated with them also led to the abandonment of individual ecological measures from the developer's point of view. Builders and investors who accept possible narrower profits for ecological measures and, according to their understanding, take a greater risk, are currently still the exception." Particularly bad experiences were made with a housing estate in Austria, whose planning was by an ecologically versed architect (Helmut Deubner), but the execution was entrusted to a conventional developer.

"Guiding Principles for Ecological Building. Evaluation of realised settlements and individual houses". (see literature source 7)
Sixteen projects out of a total of 100 projects in ecological construction were selected for the final round, ten of which were housing projects and six individual houses. The selection criterion of the study was a comprehensive ecological concept, not cost effectiveness. The pre-selection process showed that housing estates built in a community allow for ecological solutions that cannot be realised in individual buildings for economic reasons, such as constructed wetlands or combined heat and power plants. In one project, the share of own work was high, but due to the labour-intensive earthen construction method (rammed earth), no costs could be saved. Construction costs below 1,000 €/sqm as pure gross construction costs occurred in seven cases. With the exception of one well-supported project and one project with 1/3 own contribution, these are building projects that did not make high additional investments in ecological techniques. A detailed description of how costs can be reduced in ecological construction can be found from p. 267 onwards.

Position Paper "Ecological Planning and Building (see literature source 8)
The International Building Exhibition Emscher Park assumes that ecological construction and supply and disposal methods generally have a more positive economic balance than conventional systems. This positive economic effect cannot always be demonstrated to the same extent in individual economic calculations:
- The most likely case is that of ecological measures that are "state of the art" and cause no or only low additional investment costs compared to conventional measures; this also includes simply dispensing with certain environmentally harmful substances or techniques;
- less so in the case of ecological measures which, although now also "state of the art", are still significantly more expensive than conventional ones (in terms of investment or operation) and whose payback periods are correspondingly longer;
- Only in exceptional cases for those ecological measures that have to be treated separately in terms of costs due to their pilot or model character, because e.g. accompanying research and development funds have to be included.

Brochure: "Possibilities for Cost Reduction in Housing". (see literature source 9)
It documents 56 settlements and their costs. These are low-cost settlements, but several ecological settlements are also included. Unfortunately, it is not explained in detail which construction costs are meant. I mention the prices from the brochure here, even if they seem very unrealistic in part:
=> "Lindenwäldle"(p.26), Arch. Rolf Disch, Freiburg. 1985. construction costs per sqm: 394 €/sqm, self-help: 49 €/sqm (total construction costs per house with an average of 150 sqm: 59,000 €).
=> "Bad Neuenahr-Ahrweiler, Eichenweg 1-9″ (p.32), Architekturwerkstatt ac, construction costs: 792 €/sqm (1987).
=> "Herzogenrath, Haus-Heyden-Hof" (p.44), planning group "Alte Windkunst", construction costs: 580 €/sq.m. (1987)
=> Living groups "Watering mats" and "Buchenhof" (p.66), Arch. Reiner Probst, Freiburg. Construction costs per sqm: 682/ 723 € (1985/ 1990)

“Ecological architecture - a competition" (10)
This book documents 40 ecological residential buildings and settlements whose pure construction costs (according to DIN 276) are below 1,400 € (gross) per sqm of living space. All projects were built after 1992. Of the 40 projects are:
* 16 projects with construction costs below 1,150 €/m²
* 8 projects under 1,000 €/sqm have been realised
* the most cost-effective building "Wohnhaus in Kaufbeuren", cost 785 €/sqm (however, the self-help share was not stated). (p. 85)The award-winning works show that energy-saving and ecological building is possible at affordable prices. The values given in the book refer to the information provided by the architects.

"Environmentally Sustainable Industrial and Commercial Construction. A Guide."
Ed. UnternehmensGrün. 1996Economic efficiency is much more in the foreground in industrial and commercial construction than in other building projects. However, since figures and data are often only measured against so-called market prices and quality features are hardly taken into account, very short-sighted decisions are often made. For entrepreneurs, what always counts in the end are the total operating costs, which are made up as follows:Investment costs: Operating costs: Personnel costs
1 : 7 : 32These measurable figures, however, depend on many non-measurable components, such as inner atmosphere (motivation and productivity), company image, environmental compatibility of the building and the workplace. "Direct communication cannot be replaced by modern telecommunications. 80% of innovations are created in personal communication between people!" (S.69). The one per cent decrease in the sickness rate can absorb up to seven per cent higher building costs.As an example given therein, a production hall with a total of 15,000 square metres of production space in Kassel. The planning was done by the Eble architectural office in Tübingen and was carried out integrally with the relevant specialist engineers. A general contractor offered the construction as a turnkey project at a price of € 530 per square metre, including the necessary social rooms.An overview of cost reduction in ecological industrial and commercial construction can be found on p. 28/ 29.

11. examples of low-cost ecologically realised projects

Out of around 180 settlements with ecological objectives that I know of, I list below conspicuously low-cost projects:

12. Principles for ecologically cost-effective construction

1. redeployment of existing funds to finance otherwise "too expensive things", e.g. instead of several cars, a car-free housing concept with car sharing and a CHP. This is a better service and the more ecological one.
2. if conventional building and settlement technology can be replaced by ecological ones, the ecological variant will even be more cost-effective than the conventional one in some areas (e.g. decentralised drainage).
3. multiple use, mixing of functions of a building element: permaculture principles in building and settlement planning.
Ecological planning right from the start
* Integral planning with competent engineers, technicians, etc. from the earliest possible stage, i.e. including ecological concepts and technologies from the beginning. The later planning changes are made, the more expensive they become.
* professional participation: later changes are much more time-consuming and expensive. The moderation costs in 4 years of the model project Carfree Living Bremen-Hollerland are mentioned as less than 0.5 % of the investment sum for the construction of the settlement with a total of over 200 flats.
* Process control/ cost control/ quality assurance/ project management
* Good urban land use planning
* Excavated earth (cellars) and rubble (asphalt and old barracks) should be used on the site for landscaping if possible
Building construction/ building structure
* Wooden stud wall with thermal insulation is thinner than a solid wall with the same k-value, thus more living space.
* no dry living!
* Board stack ceilings and walls (according to J.Natterer)
* Wooden houses are lighter, smaller foundation
* (Floor) ducts not necessary: construction-related cavities in timber construction save approx. 15 €/sq. m.
* Modular construction/ grid system/ high degree of prefabrication (wooden studs)
* compact building structure
* flat monopitch roof: only one drainage, simple static system
* constructive instead of chemical wood preservation (weather-resistant wood species such as oak, Douglas fir, etc.)
* Limitation to a few materials
* Mass rabble
* Price comparison of wall constructions with the same k-value (data from LBTA lecture):
Wooden construction: 92 €/sqm (100%) (wooden post and beam construction with conventional thermal insulation infill)
Masonry: 105 €/sqm (114%)
Core insulation: 180 €/sqm (195%) (11.5 cm KS, 4 cm air, 8 cm Styrofoam, 17.5 cm KS, interior plaster)
Note: Prices, however, vary greatly from region to region and season to season. If the carpenter has a lot of work, but the bricklayer has little to do, the masonry wall may be cheaper. Furthermore, cost advantages through prefabrication in timber construction are compensated by cheap labour.

Construction
* Rationalisation on construction site, e.g. plastering machine, blow-in insulation material, ...
* qualified companies

13. Building cost considerations using the example of

Clay
* Costs and economic efficiency
Already today, an earthen house, i.e. a house in which earthen building materials are largely used, is no more expensive than a conventionally built house, and this in professional execution by companies. With the availability of earthen building materials on the construction market - now in its infancy - their use will become more natural and safe, and the growing demand will contribute to the competitiveness of earthen products in wide areas.
A comparison of material prices with other building materials shows that earthen building materials can be cheaper today and still fulfil the same purpose. However, it must be taken into account that most earthen building materials can only be used in non-load-bearing applications. As infill materials for skeleton construction and timber frame renovation, many earthen building materials are already superior to conventional building materials in terms of price.
* Self-help processing
Most earth building materials and methods are particularly well suited for self-help. The techniques are easy to learn and not too physically demanding, so lay people, helpers, friends and the whole family can be used.
* Standards
The earthen building DIN, which was withdrawn in 1971 because it was "outdated", is currently being revised and will be reintroduced. This is an important contribution to reducing costs.
* Rating
In summary, it can be said that there is hardly any other building method that corresponds to today's ecological, building physics and health considerations as well as earth building, which, however, is only beginning to be developed into a modern building method through the initiative of individuals.
[S. 121 (12)]

Roof plantings
Planted roofs store up to 90% of rainwater and release the runoff (10%) with a delay. This has the advantages that the sewage network and sewage treatment plants are not burdened, rain overflow basins are not necessary with widespread greening, receiving waters (amtsdeutsch: "streams and rivers") are not burdened and the groundwater level does not sink. Roof plantings absorb pollutants from the air and improve the microclimate, since in summer only 8% of the solar radiation is reflected again. As a result, the roof structure heats up only slightly in contrast to bitumen roofs, for example, which can reach temperatures of up to 60 degrees during hot spells and strong sunlight. The strong temperature fluctuations of bitumen roofing lead to high maintenance requirements and associated costs.

Car-free living
* With a number of parking spaces of 0.2/unit for 300 units, the construction of 240 parking spaces is saved. If the parking spaces were underground garages, this corresponds to 240 x 20,000 € = 3.6 million €, which can be saved or used for other purposes.
* Living without one's own car saves on average about 75 to 150 € per month [Verkehr in Zahlen 1989] or in extreme cases: up to 1,500 € per month [Mercedes 600S; Bad. Zeitung 23.3.94] with the same annual mileage of 13,000 km by federal railway, public transport, car sharing, taxi, bicycle, walking and delivery of large items such as furniture.

Development
* Car-free development with narrower and less paved, open-pored cycle paths and footpaths, which can only be used for ambulances, etc., are cheaper than asphalted roads.
* Develop settlements as large plots. This makes it possible, for example, to have a common trench for electricity, water, sewage, vacuum toilets, TV cable, telephone, etc., which would otherwise have to be laid in separate trenches. A main telephone and TV connection in the settlement and the subsequent internal distribution is cheaper than connecting each flat separately and has the advantage of free telephone calls within the settlement.

Energy
Examples of proven economically realised energy technologies:
* Energy-saving household appliances:
An energy- and water-saving washing machine saves between €140-€1200 in 15 years of use.
Electricity-saving refrigerator saves between €345 and €1,560 in operating costs in 15 lifetimes
* Swimming pool absorbers are more cost-effective than conventional burners.
* Biomass, such as straw firing plants, wood chips, biogas plants in sewage treatment plants,...
* Wood chip CHP plants, biogas CHP's, wood gasification plants,...
* Low-energy houses: additional costs due to additional insulation between 2.1 and 8.4% [Study IWU, Darmstadt; p.228 (4) ]. * Passive house: additional construction costs of the pilot project Kranichstein amount to 286 €/sqm living space, about 16% of the pure construction costs. With an improved, slimmed-down variant (abandonment of inefficient technologies that did not produce the expected results in the pilot project), the additional construction costs would fall to below 13% of the construction costs [p.230 (4) ]. * Solar local heating
Ravensburg: 50% Cost reduction for large-scale collector system and local heating pipe compared to individual systems on each building
Hamburg.Bramfeld: Use of prefabricated solar roof collectors. Collector as roof covering

The price per square metre of installed collector area is about 250 € for systems of this size (such as Friedrichshafen-Wiggenhausen (4450 square metres of collector area) or Hamburg-Bramfeld (3520 square metres), which is only a quarter of what small systems cost. At about 26 Pf./kWh of solar heat, such systems will soon be in the realm of economic competitiveness." [p.128 Art. "Integrale Energiekonzepte in Deutschland" by N.Fisch and A.Lutz in "Solararchitektur für Europa", ed. Astrid Schneider, 1996]

The world's largest project is in Marstal Fjernvarme, Denmark with 8000 sqm collectors and 2100 m3 buffer storage with a specific heat price of 7 Pf/ kWh, which corresponds to heat production prices of oil or gas. The plant supplies 13% of the annual heat demand. In the 3 summer months 100%.

Social
* Shared facilities save money (communal house, car sharing, workshops, offices, photo lab, sauna, guest room, children's playroom, multi-purpose rooms, laundry room, ...) and, if well planned, reduce the space needed in the individual flats. This requires more organisation (rules) and more communication.

The cohousing project "Jystrup Savvaerket", Denmark
21 residential units, occupation: 1984, community house 404m2, residential street 795m2
The special feature of this cohousing project is the residential street covered as a glass gallery. In earlier projects without glazing, the activities in the communal house were always very slow in winter. For the usability of the common rooms, it is important that one can "go over there for a moment" even in a jogging suit. The glass roof protects the residential street from the weather and makes it possible to use the common rooms all year round.

* Self-government saves administrative costs

Building Biology
* PVC-free cables with shielding against electric fields have a higher material price (8 to 10 times). However, as the labour costs account for the major share, the additional costs only amount to approx. 2% of the total costs for halogen-free cables and 6- 8% for halogen-free and shielded cables. Much more important is the thoroughness of the planned cable routes and the supply concept. Here, intelligent planning can halve the amount of material. This is where costs can really be saved. [Data from (12) section 5.4] * ...

Funding
* Muscle mortgage through self-help can help save capital costs, but be careful: realistic assessment of capacity is important to avoid construction delays and associated additional costs.
* Least-cost planning
* Contracting
* Cooperative financing models
* joint borrowing by a community of builders

Subsidies
* Eco-bonus for energy-saving measures, solar installations, etc. by the federal government
* Construction subsidies can be claimed, as for any other construction project.
* Lower-interest ethically sound loans at environmental banks, such as Ökobank Frankfurt, Umweltbank, Munich, GLS Bochum.
* Cost-covering remuneration for solar electricity enables the financing of photovoltaic systems.
* Market introduction grants for new technologies

14. Outlook

"...to get ecological building out of the niche of model projects and into the centre of innovative building processes. It must succeed in developing ecological building into a relevant factor in the construction industry." Dr. Michael Vesper, Minister for Building and Housing NRW [p.1 (1) ]

Cost reductions of ecological construction are to be expected through:
* greater demand
* Rationalisation of production
* Technical developments
* Standardisation
* With increasing experience of the construction companies and craftsmen, "fear surcharges" are reduced or eliminated.
* More prefabrication
* Quality improvement
* Better marketing
* better information
* more competent planners

15. task of the universities:

This is a challenge for the universities. In the normal everyday life of architects, further training is very laborious or even impossible to impart. By and large, the experimental phase of ecological building is over. The know-how is there. The problem is that the knowledge is not available to the masses. In this respect, the universities are not living up to their role as thought leaders and knowledge transfer institutions. There are some rays of hope here and there, but overall, no significant impulses can be expected from the universities so far. While they are still more active in research, there is an almost universal lack of mediation to students. Who is surprised that the future planners lack ecological know-how?

16. download: Possibilities for cost reduction in housing construction.

Savings catalogue of the "High quality - affordable costs" campaign - ways to reduce costs in housing construction. From: Federal Ministry of Regional Planning, Building and Urban Affairs: Bauherrenpreis 1986 - 1996. Action: High quality - affordable costs. Bonn, 1996 I

1996I

5 S.

36 kB

I

17. literature "inexpensive ecological building".

(1) "Ecological & economical building in practice. Information for everyday life. Conference proceedings Ökobau-Kongreß 1996." Ed. Olaf Paproth/ Wolfgang Ruske. Synergy Wood! Publisher
(2) Öko-Bau Institut für ökologisches & wirtschaftliches Bauen, Krefeld, self-presentation, 1996
(3) "Cost-effective ecological planning and building. Proceedings of the 5th European Symposium on Ecological Building, 3 and 4 June 1996, Copenhagen, Denmark." Ministry for Building and Housing of the State of North Rhine-Westphalia.
(4) "Die Wirtschaftlichkeit des Ökologischen Bauens", conference proceedings for "terra-bau" 1995 in Hanover.
(5) "Ökologischer Siedlungs(um)bau." Ed. EA.UE (European Academy for Urban Environment), Berlin, in cooperation with Öko-Zentrum NRW, Hamm. 1996.
(6) Study "Zukunftsweisender ökologischer Siedlungsbau in Europa - ein Erfahrungsbericht". EA.UE, Berlin in cooperation with Öko-Zentrum NRW, Hamm. 1993 p.1 ff: Cost and benefit analyses, Chapter VIII/ p. 18 ff: Implementation of decentralised systems.
(7) "Leitbilder für ökologisches Bauen. Evaluation of realised settlements and individual houses." Published by Akademie für Bauökologie e.V. and Hochschule für Technik und Wirtschaft, Saarbrücken. 1996
(8) Position paper "Ecological Planning and Building". Emscher Park International Building Exhibition. 1996. S.23/ 24
(9) "Bauherrenpreis 1986 - 1996, Action: High quality - affordable costs. Possibilities for cost reduction in housing construction." Federal Ministry for Regional Planning, Building and Urban Development. 1996
(10) "Ecological architecture - a competition. 40 selected examples of environmentally conscious building - living - life." Ed. Horst Kleiner. 1995
(11) "Environmentally sound industrial and commercial construction. A Guide." Ed. UnternehmensGrün. 1996
(12) Building materials and ecology. Evaluation criteria for architects and builders. Ed. Haefele, Oed, Sambeth, Tübingen. 1996
(13) "Who lowers the housing costs?" Joachim Brech, Holger G. Schwenzer (eds.), 1984 Darmstadt

Norbert Post, Hartmut Welters (1998): Wohnqulität - kostenoptimiert. Recognising and using cost margins, taking new planning paths, increasing utility values. Cologne