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Urban Structure

Master plan of Vauban, Freiburg, Germany. The City of Freiburg in Germany planned an energy conscious housing on a former brownfield area The plan includes a number of Passive Houses.
Low-energy and passive houses in Vauban area, Freiburg, Germany.
Energy demand of a neighborhood of 1000 inhabitants in Tampere, Finland. By low-energy and passive technologies the total energy demand can be decreased by about 50%.

Master planning
A master planner can greatly influence on the energy demand of the neighbourhood. The ways and means to promote urban energy-efficiency by master planning are compactness of the area and building structure, evaluation of the design area and utilization of site characteristics, location and orientation of buildings on individual sites, and minimizing over-shadowing between neighbouring buildings and design areas.

Compactness of the area reduces energy distribution losses, but too dense area may reduce the possibility to utilize solar energy. Compactness of buildings can reduce exposed surface area and hence heating energy demand and consumption in cold climates.

In a cold climate passive solar heating may give an important contribution into a building’s energy balance, but at the same time passive cooling need to be addressed even in cold countries. A Passive House should utilize free energy sources efficiently. Development plans should thus encourage passive heating and cooling design and shelter from extreme climate conditions.

Passive Houses
An urban neighbourhood of Passive Houses has many economical benefits. The low power demand is beneficial for the energy infrastructure. Also, local energy production on the scale of an urban area becomes a feasible option because of the low energy demand. While the regulatory and even voluntary actions have started to decrease the heating energy demand in many countries, consumption of electrical energy is still increasing.

Minimising energy demand increases economic viability of renewable energy. A Passive House has minimized heat losses, and thus a larger share of building's heating energy can be covered economically by passive solar gains. The remaining energy demand can then be covered by active solar systems or other renewable sources.

Passive Houses are suitable for renewable energy and distributed supply schemes. Renewable energy systems are well suited for local energy supply systems, and they become more attractive as the total energy demand becomes lower. Renewable energy has positive economic impacts. It causes a shift from energy import to domestic production and renewable supply, which in turn has positive effects on employment and value creation. Local energy production systems with lower peak power production are less vulnerable to grid over-loading. Utilization of renewable energy sources is a vital part of sustainable buildings and neighbourhoods.

Energy benefits
The end use of energy in a neighbourhood can be described by the total annual heating, cooling, electrical and other household energy consumption and their peak demands. The size and capacity of heating, cooling or electrical energy production systems is directly related to the peak power demands of the whole neighbourhood (and/or individual buildings).

A Passive House represents the most efficient energy saving measure on the individual building and neighbourhood scale.

Depending on the local climate, passive solar energy can bring an important contribution to heating of a house. Passive solar heat ranges from 1 to 60 kWh/m2 annually, but the energy benefit depends also on how the house is being used. The major strategy to utilize passive solar energy is direct gains through windows.

A good master plan can reduce a neighbourhood's total energy demand by estimated 10 - 15%. Through optimising the site and buildings for passive solar energy, a neighbourhood's energy demand can be reduced by approximately 15 - 30%.