Energy certificate for a detached house

In this article on energy certificates for detached houses, we explain what requirements the law and decrees set for the energy performance certificate (energiatodistus) of a detached house (omakotitalo). Under the Energy Performance Certificate Decree, a detached house belongs to use category (käyttötarkoitusluokka) 1 a–c, small residential buildings, which have their own energy efficiency requirements for new construction. When an existing detached house is sold, however, there are no energy efficiency requirements at all. An energy certificate is mandatory when selling a detached house, even though you sometimes see sales listings with the note “No energy certificate required by law” – only buildings under 50 m2 are exempt from obtaining an energy certificate. Selling a home without an energy certificate can be a bad idea, though, as ARA (the Housing Finance and Development Centre of Finland; since 1.3.2025 Varke) has stepped up its supervision since 2021 and, according to Yle, conditional fines (uhkasakko) have been imposed after sales. A new detached house also needs an energy certificate in order to obtain a building permit. Whether you are interested in an energy certificate for a new detached house, ordering one for an older detached house, the price of an energy certificate or other energy consulting, please get in touch! We draw up energy certificates for detached houses quickly.

Energy certificates from our company and the price of a detached house energy certificate

You can easily ask for the price of an energy certificate for a detached house by filling in the quote request form on our website. We produce energy certificates for both old and new detached houses. The energy report (energiaselvitys) required for the building permit of a new detached house is also a typical assignment for us. We offer energy consulting for all building types and reliably prepare the reports needed for energy grants. If you wish, you can also order investment profitability calculations and life-cycle cost calculations from us for various energy-saving solutions, such as air-source heat pumps, solar panels or ground source heat systems. Don’t hesitate to contact us – we are happy to advise you, whatever your energy matter.

The detached house energy certificate in brief

The requirements for new and old detached houses are different.

Old detached house

When you sell an existing detached house, you need an energy certificate.

• An energy certificate on its own is enough; you do not need an energy report.
• There are no energy efficiency requirements for existing buildings.

New detached house

A new building requires an energy report in addition to the energy certificate.

• You need an energy report in addition to the energy certificate for the building permit.
• The energy efficiency requirements for new buildings are laid down in decrees of the Ministry of the Environment. If the current plans do not meet the energy efficiency requirements, we can, if you wish, find the most cost-effective way to meet them.

Energy certificate, E-value and energy report

The energy certificate is a certificate of a building’s energy efficiency, and the E-value (E-luku) is its most important figure. The E-value describes energy consumption weighted by energy carrier factors per heated net floor area per year. In other words, the E-value expresses how many kilowatt hours of energy, weighted by energy carrier factors, are consumed per square metre per year. If, for example, the E-value is 112 kWhE/m2a and the heated net floor area is 100 m2, the calculated annual energy consumption of the whole building, weighted by energy carrier factors, is 11 200 kWh. Energy carrier factors (energiamuotokertoimet) are the factors by which energy consumption is multiplied for the E-value. The energy carrier factor for electricity is 1,2 and for district heating 0,5. If the electricity consumption calculated according to the decrees is, for example, 70 kWh/m2a and district heating consumption 56 kWh/m2a, the E-value is 70 x 1,2 + 56 x 0,5 = 112 kWhE/(m2a). The E-value is therefore always calculated from the plans and standard values, and it does not take into account the building’s actual energy consumption, which depends on the occupants and on annual weather conditions.

An energy report is a broader study than the energy certificate of a building’s energy efficiency and, depending on the building type, also of calculated indoor temperatures. The energy certificate is included in the energy report along with other documents. Small residential buildings, which include detached houses, are not required to have an indoor temperature assessment, so the energy report is only a slightly more comprehensive set of documents than the energy certificate alone.

How is an energy certificate made?

An energy certificate is made in accordance with the Ministry of the Environment Decree on the energy performance certificate of a building, 20.12.2017/1048. The decree sets out what must be taken into account in calculating the E-value and drawing up the energy certificate. Some of the values used in the calculation are standard values, such as the energy consumption of domestic hot water, and some are design values, such as the thermal insulation of the walls. Calculating the E-value of an energy certificate with pen and paper is possible in theory, but in practice all energy certificate assessors use calculation and simulation software because of the complexity of the calculations. For existing buildings, a site visit required by law is also carried out to gather additional information about the property.

Energy efficiency classes of detached houses

The E-value, which describes energy efficiency, determines which energy class a detached house falls into. There are energy efficiency classes A–G, where A is the best and G the poorest. The E-value is calculated in the same way for all detached houses, but the energy efficiency class derived from it differs for detached houses of different sizes. This is probably because a larger house is, relative to its floor area, inherently more energy-efficient than a small one, so comparing the energy efficiency of buildings of different sizes on the same principles would not be fair.

Small residential buildings, over 50m2 but under 150 m2 (incl. detached houses)

Calculating with the formulas in the table below, a 50 m2 detached house, for example, falls into energy efficiency class B when its E-value is 101–185 (110 – 0,2 x 50 = 100 and 215 – 0,6 x 50 = 185). If the floor area of the building is 75 m2, class B is reached, using the same formula, with E-values of 96–170.

Small residential buildings, 150 m2 but under 600 m2 (incl. detached houses)

A 150 m2 detached house falls into energy efficiency class B with E-values of 81–125 (83 – 0,02 x 150 = 80 and 131 – 0,04 x 150 = 125). A 200 m2 building is in class B when its E-value is between 80 and 123.

Small residential buildings, over 600 m2 (incl. detached houses)

A building falls into energy efficiency class B when its E-value is 71–106.

Energy efficiency classes, small residential buildings, use category 1 a–c
Energy efficiency class	E-value, kWh/(m² year)
Size group: 50 m² ≤ Anetto ≤ 150 m²
A	E-value ≤ 110 – 0,2 × Anetto
B	110 – 0,2 × Anetto < E-value ≤ 215 – 0,6 × Anetto
C	215 – 0,6 × Anetto < E-value ≤ 252 – 0,6 × Anetto
D	252 – 0,6 × Anetto < E-value ≤ 332 – 0,6 × Anetto
E	332 – 0,6 × Anetto < E-value ≤ 462 – 0,6 × Anetto
F	462 – 0,6 × Anetto < E-value ≤ 532 – 0,6 × Anetto
G	532 – 0,6 × Anetto< E-value
Size group: 150 m² < Anetto ≤ 600 m²
A	E-value ≤ 83 – 0,02 × Anetto
B	83 – 0,02 × Anetto < E-value ≤ 131 – 0,04 × Anetto
C	131 – 0,04 × Anetto < E-value ≤ 173 – 0,07 × Anetto
D	173 – 0,07 × Anetto < E-value ≤ 253 – 0,07 × Anetto
E	253 – 0,07 × Anetto < E-value ≤ 383 – 0,07 × Anetto
F	383 – 0,07 × Anetto < E-value ≤ 453 – 0,07 × Anetto
G	453 – 0,07 × Anetto < E-value
Size group: Anetto > 600 m²
A	E-value ≤ 70
B	71 ≤ E-value ≤ 106
C	107 ≤ E-value ≤ 130
D	131 ≤ E-value ≤ 210
E	211 ≤ E-value ≤ 340
F	341 ≤ E-value ≤ 410
G	411 ≤ E-value

how the energy efficiency classes of small residential buildings are determined