How to improve your home’s energy rating
Following an analysis of consumption and the identification of the main heat loss points, it is possible to intervene in a number of ways, from thermal protection envelopes to replacing heating systems
Published on 2 December 2019
Do you live in a property that scores the lowest of the energy classes, Class G, and you want to improve the rating? Where to start? Is it better to change the boiler or replace the windows?
When opting to improve energy performance in a residential property it’s best not to make any rushed choices. First, an energy audit is required: this is an analysis carried out by experts to identify the weak points in the heating system and in the insulation offered by the building’s outer layer.
Energy performance analysis uses tools such as infrared thermography to identify “thermal bridges” responsible for the greatest heat loss. The Blower Door Test method, meanwhile, identifies the points in a building’s outer layer, such as doors or windows, that are most responsible for draughts or heat loss.
Only after a serious energy audit has been carried out is it possible to choose which type of intervention is required.
The outer walls of a building could, for example, benefit from a thermal protection envelope, where layers of insulating material are applied to the façade (Exterior Insulation and Finishing System -EIFS) or insulation could be applied inside the home. While the former operation involves the external façade of a residential building, the latter can be carried out in individual properties by installing insulating layers on the inner surfaces of perimeter walls. Another improvement option is to replace existing windows with more efficient models that provide insulation through double or triple glazing or even inert gas-filled windows to reduce transmittance (heat transfer rate).
There is also a wide range of systems options available, depending on the results of the energy performance analysis and the existing heating system (a centralised system for the entire building or autonomous system for each individual home).
If there is a centralised heating system for the entire residential building, in addition to replacing the boiler with a more efficient model or a heat pump, it can also be useful to install smart radiator thermostat valves or smart thermostats, that can also be remotely controlled, to improve consumption in individual areas (e.g. reducing heating in rooms that are not being used). The use of a heat metering system which measures consumption in individual apartments and therefore produces a correct attribution of heating costs (based on the amount used rather than property measurements) can further encourage building residents to adopt more responsible behaviour.
If, however, the heating system is autonomous there is an even greater range of action possible and the boiler can easily be replaced by a more efficient type, such as a condensing model, together with an underfloor heating system that removes radiators and maximises efficiency. Another option is to install a heat pump (air-air, air-water, geothermal) and replace radiators with fan coil units, which means that the same system can heat in winter and cool in summer.