When you start building a house, you are probably committing to a project that is the biggest investment of your life and impacts your finances a lot. In order to keep the cost of a new house reasonable and to manage it economically, you should think carefully about energy saving during the design and interior design phases.

Building an energy-efficient house starts with a proper design where using the features of the existing plot pays off. The position of the house with respect to the cardinal directions determines which sides of the building receive the most sunlight and which ones receive the most wind load. Sun exposure in the east, west and south allows to reduce heating costs. Wind exposure increases its cooling effect and requires that more attention is paid to wind resistance.

The size of the building's heated surface affects the heating demand of the building. The golden rule is that the more wall space per floor area, the higher the heating cost. For example, compact and large rectangular or square buildings are the most energy-efficient. On the other hand, small buildings with the same capacity that have lots of nooks and crannies or a large double-pitched roof are wasting energy.

The surface area and location of windows also have a great impact. Energy loss through windows and window frames is several times greater than energy loss through walls or the roof. The layout of the windows is also very important. No direct sunlight comes from the northern windows, but windows on the east, west and south sides can be used for heating the space. However, they should be covered with curtains or window covers in the summer to avoid the need for excessive cooling.

The total energy saving capacity of a building also depends on the heating system. In general, systems based on renewable energy – such as geothermal heat pumps – are the best. When building a new house, usually no landscaping has been done yet, so installing a geothermal heat pump can also be considered during the planning phase.

Artificial lighting and home appliances play a major role in the construction of an energy-efficient house. The energy label tells you how much energy or other resources a home appliance consumes. When choosing a new home appliance in the store, it is worthwhile to pay attention to the energy label so that the choice is also cost-effective in the long run.

Generating solar power in your own home or business is gaining popularity everywhere. The most common system for solar power generation is the on-grid system. This means that the system owner can consume as much electricity from the solar panels as they need and sell the rest to the grid. If the owner's consumption is higher than the amount of electricity produced by the solar panels, the missing amount can always be purchased from the grid.

By investing into a solar system, you benefit in two ways. Firstly, each kWh of electricity produced by solar panels and consumed on-site reduces the amount of electricity that would otherwise have to be purchased from the grid, therefore also eliminating grid charges. Secondly, if the solar panels produce more energy than can be consumed, the remaining energy can be sold to the grid and thereby money can be made from the sale of electricity.