Home energy ratings explained

What is a home energy rating and what does it mean in practice?

A home energy rating gives an indication of a building’s demands on electricity, gas and water. It also covers carbon dioxide emissions, insulation, lighting and ventilation. The rating uses a scale from A to G.

A means maximum efficiency, while G is the lowest possible rating. Spain’s housing stock is old, and low ratings from E to G are commonplace.

So what are energy ratings actually good for? An energy rating distinguishes between efficient and non-efficient buildings. If a home has a low rating, that does not mean there isn’t room for improvement. With the right refurbishment or changes, a home can achieve a better rating, and the top score is possible by implementing good design and energy efficiency measures.

But what does that actually mean?

• Design: should factor in sustainability.
• Energy efficiency: includes prioritising renewable energy, implementing high-efficiency ventilation and lighting, and thermal and acoustic insulation.

Applicants wishing to obtain an energy rating need to request an energy efficiency certificate.

Energy efficiency indicators

The energy rating for flats and single-family homes is based on a series of indicators which are worked out annually. Said indicators are updated based on the quality and usage of lighting, ventilation and insulation. The same indicators apply to all types of buildings, including offices and retail premises. That means there is no exclusive rating system for private homes.

All buildings are supplied with electricity, water, ventilation, lighting, refrigeration and heating, etc., irrespective of the intended use and occupation level.

These are the most important indicators:

• Annual consumption of primary non-renewable energy in kilowatt hours (kWh) per square metre of useful space.
• Annual CO₂ emissions in kilograms per square metre of useful space.

This information is used to calculate how efficient the energy supplies are. Buildings rated A consume around 90% less energy that those rated G. Those rated B and C use approximately 70% and 35% less, respectively.

There are also additional indicators which are calculated annually. These enable us to analyse why energy is being used efficiently or poorly, and provide information to help make improvements. Like the first batch of indicators, they are based on consumption per square metre of useful space:

• Consumption of primary non-renewable energy for essential building services.
• Annual CO₂ emissions for main services.
• Energy required to build each of the main services.

For new-build, the following factors are used to obtain the indicators:

• Orientation of the building.
• Thermal insulation and the thermal envelope.
• Quality and type of artificial lighting, heating, refrigeration, hot water and ventilation installations.
• Use of renewable energy generation or supply systems.

Given the energy savings possible with the use of LED luminaires, these can have a positive effect on a building’s energy rating. They also reduce the overall carbon footprint since they are durable devices requiring little maintenance and few replacements.

Requesting a home energy efficiency certificate

The certificate can only be issued by a qualified expert or company that provides this service. After conducting the necessary research, they issue a document detailing the following:

• Information about the building. It may include just part of the home. If so, only that part of the building is rated.
• Details of the procedure followed for the study and rating.
• Tests, inspections and checks performed.
• The building’s energy characteristics.
• Applicable regulations at the date of construction.
• The energy rating awarded after the study, i.e. the applicable letter A to G.
• Details of faults detected or possible improvement areas, and a technical feasibility study of the proposed changes.

The measures proposed to improve a building’s energy usage are rating are not legally binding and it is up to the homeowner whether or not to proceed.

The advantages of a good energy rating

A good energy rating has several benefits, including the following:

• It means the home is energy efficient.
• The home contributes to sustainable development and the green transition.
• Energy expenditure is lower.
• The market value of the property is higher.
• There may be tax breaks available (for example, the annual Spanish property tax (IBI) may be lower).
• The building has better lighting, ventilation and temperature, and is therefore more comfortable.

LED lighting products from Secom

Secom supplies a range of sustainable and energy-efficient lighting solutions for achieving big energy savings, not to mention their optimal performance, resistance and durability.

At Secom, we can help you to improve a home’s energy rating with quality lighting. Don’t forget that LED technology can achieve savings of around 90% compared with conventional lighting devices.