Setting aside the zero-energy house that requires an investment into the acquisition of a local energy system, let’s look at the heating cost of the basic module of Elumaja that complies with the passive house standard and compare it with the most popular types of heating: firewood, heating oil and gas.

The heating value of heating oil is 9.8 kWh/l that means that a passive house would use 1.5 l of heating oil per square metre a year. For heating Elumaja (135 m²) it would require 202 litres or about a 200-litre-barrel of heating oil a year.

The heating value of gas is 9.3 kWh/l and the annual heating cost of the passive house is 1.6 l/m². For Elumaja (135 m²) it means 217 litres of gas a year.

Ecologial footprint is a benchmark that measures the use of natural resources necessary for operation. It assesses the use of space in relation to the lifecycle of the product or service and can be measured in hectares per year. The ecological footprint index shows how much fertile land and water has been used for the production, use and absorption of materials that are being consumed. The ecological footprint of Elumaja is the smallest possible, without compromising anything on convenience or durability.

• Annual heating cost: 150 kWh/ m² or more
• household appliances and lighting are generally not adjusted
• maintenance costs before the completion of the building cannot be forecast

• Heating cost 15 kWh/ m² a year
• household appliances and lighting are adjusted
• maintenance costs can be forecast

• unavoidable in the use of electricity since the consumption is high and the cost of a renewable energy system is therefore high
• possibility to collect and use rainwater
• possibility to solve wastewater treatment locally
• possibility to use solar energy if consumption is high, but requires a big investment.

• possibility when using electricity, consumption is low and the system cost is affordable
• collection and use of rainwater is available as a package solution
• wastewater treatment is available as a package solution
• the possibility of solar heating has been considered during the designwork, both consumption and investment requirement is moderate

• depending on the building type, self-regulated or partly controlled, including humidity
• structural and finishing materials are not generally selected on the consideration whether they contain toxic substances  and on the quality of indoor air
• natural ventilation or ventilation without heat recovery, dimensioned air exchange, high or widely fluctuating CO2 concentration, fluctuating air quality
• usual space comfort, but may cause a convection effect that creates an uncomfortable feeling in the otherwise warm room (cold floor, chill air near wall or windows)

• controlled, functions in automatic mode, regulated according to the needs of the people in the room
• materials are processed as little as possible, do not contain toxic substances and help to balance air humidity and temperature fluctuations (e.g., clay plaster)
• heat-recovery ventilation with a coefficient of at least 85%, air exchange is dimensioned and CO2 concentration is low, air in the room is fresh
• convection effect is avoided since no thermal bridges can occur in boundaries
• suitable for highly sensitive people.

• usually not considered important, therefore it is difficult to calculate
• disposal of construction materials after the end of the building’s life cycle can be complicated and expensive (e.g., OSB and gypsum boards, mineral wool or plastic window frames)
• the amount of primary energy used in the production of construction materials (e.g., concentration of CO2 emissions) is not usually measured nor is measured the emission of greenhouse gases that are generated during the building use
• ecological footprint actually increases  during the use of the building.

• measuring the ecological footprint is one of the objectives that is monitored and measured from the start of the construction process until the end of the building’s life cycle
• when the building’s life cycle ends, the materials can be either re-cycled or disposed safely
• the amount of primary energy and minimum emission of greenhouses gases
• during both the production of materials used for manufacturing the house and the maintenance are a special objective and can be measured
• ecological footprint of a zero-energy house shrinks during the use of the house.

• if is relatively favourable to buy a catalogue house, but the customer needs to consider the time that he or she needs to contribute to the construction process and handling the case, while a turnkey project costs the average market price
• in case of special design, one square metre of the house including indirect costs and the time spent on construction would be likely to cost more than the market average
• significant running cost, heating cost is at least 10 000 kroons a year (45 m² house)

• price is market average and fixed, customer’s input in the construction work and the necessary paperwork is limited
• Building of Elumaja (45 m²) requires only a written permit of the local government authority and is simple and easy
• Low maintenance cost, heating cost starting from 1000 kroons a year (45 m² house)

• theoretically possible if space elements are used, which is rare
• traditionally, the building is born and dies in the same place

• Elumaja is like a Lego set that can be assembled and disassembled as you need. Physical relocation of modules is easy
• for instance, you can start by acquiring a 45 m² summer cottage in countyside and end up with a 135 m² house in City, having acquired and added two 45 m² house modules

• initial emotion is certainly positive

• the emotion is great whether at the start, in the middle or at the end
• soon everybody will be talking about efficient and ecological houses, but you will be already living in one :-)