Energy Efficiency and Older Houses
Many people think that older houses are not energy-efficient, and must be radically upgraded in order to improve their performance. In reality, the situation is more complicated and assumptions about poor performance are not always justified.
The energy and carbon performance of older houses can often be improved. However, striking the right balance between the benefits and harm is not always easy.
Getting energy efficiency measures wrong or doing them badly can result in damage to the historic building and its fabric, and potential harm to your health. Predicted energy or cost savings or reductions in carbon emissions may not be realised.
The whole house approach
The best approach is to look at your whole home, its own environment, construction, condition and historic significance. You need to know all the factors that affect energy use in order to devise your own energy efficiency strategy for your home.
The four most important factors are:
- House location and orientation
The performance of a house will be affected by your local climate and its exposure to wind, rain and sun.
- House design and fabric
The form and design of the house, the construction materials and components and their condition also affect energy performance.
- Services and equipment
Heating, cooling, lighting and ventilating a house all use energy. So does the equipment and appliances we use for cooking and entertainment.
We all use our houses in different ways. The amount of energy we use varies too. The number of people in a house, the levels of comfort they expect, and the services and equipment they use all have a significant effect on how much energy a household consumes.
To understand the energy performance of a house - and identify opportunities for improvements - it's important to view it as one large interactive system. We have summarised these interactions in the building performance triangle diagram below:
Although there are no ‘one-size-fits-all’ solutions for making energy and carbon savings in older houses, there are some general principles that apply across the board:
Understand your home and its context
- The historic significance of your house and the potential harm from changes
- Its exposure to sun, wind and rain
- Its design, construction and condition
- The performance and behaviour of the building materials
- The design, condition and operation of services such as heating and hot water
- How you use your home
- Your own requirements, aspirations and aims
- Your budget and other resources, opportunities and constraints
Success cannot be achieved by technical means alone; everyone in the home needs to be fully involved in your energy saving plans.
Reduce energy use
Review and question your current habits and comfort standards to find out what's really necessary. You might be able to make energy savings through a more flexible approach to comfort in different parts of the home, so for instance by heating bedrooms to a lower temperature than living rooms.
Lights and equipment in homes are often left on unnecessarily. It's important to use energy-using systems efficiently, and to turn all energy-using equipment off or down when not needed.
Building services such as heating, hot water supply and lighting and other energy-using equipment like computers and appliances should be designed, selected and run to use as little energy as possible.
The thermal efficiency of your building can be enhanced both by carrying out regular maintenance as well as adding insulation where this can be accommodated.
Heating control systems should be efficient as possible and easy to understand and use. Many systems are not as manageable and responsive as they could be. This can lead to increased energy use.
Use lower carbon energy supplies
Switch to energy sources with lower emissions such as on- or off-site renewable energy (solar, wind or water power), or select lower-carbon supplies such as gas or wood instead of coal.
Solutions should be kept as simple as possible and done well.
When you review how the measures you've taken are perfroming, check their performance as part of the overall system. Watch out for unintended consequences such as overheating, moisture problems and poor indoor air quality.
Measures used in combination can have a powerful multiplier effect. For example, combining a 50% reduction in the demand for energy and the amount of carbon in the energy supply with a 100% increase in equipment-efficiency can cut carbon emissions by seven-eighths.
The whole building approach is explained in more detail in our guidance:
For help with making changes to improve energy efficiency see our page:
Making changes to save energy