August 4, 2022

How to calculate heat loss in your home

Home efficiency rating next to half a house outline

Calculating heat loss and determining the energy efficiency of a building is an important part of a heating engineer's job.

Completing this process involves taking accurate measurements of a home, including the length and dimensions of windows, walls, doors and radiators as well as a detailed review of loft insulation and cavity insulation. Additionally, an engineer will need to determine the U-value, which is used to quantify the conductivity of a material.

Once all this information is worked out, it is possible to put together a heat loss calculation that will tell you how energy efficient your home is. Based on this information you will be able to determine the scale and power of the heating system you need.

To make things easy for you, we have included a heat loss calculator at the bottom of this blog, to help you work out your heating efficiency.

Why do we perform heat loss calculations?

When fitting your home for a new heating system, whether that be a new gas boiler, electric storage heater or a ground source heat pump, it’s important to understand how heat is conserved and lost in your home.

If you have a poorly insulated home, then you will require a powerful heating system that can produce enough heat energy to compensate for the heat lost. Whereas if you have a well-insulated home then you will require a less powerful heating system to fulfil your heating needs.

This can often cause issues when people have their boilers refitted. Older boilers are much less efficient than modern replacements, however, this is not always appreciated when the new boiler is fitted.

Replacing an old unit with a modern boiler of similar size can mean you end up paying more for an overly powerful heating system. This is one reason why it’s important to make sure you calculate heat loss properly.

More importantly, if you get a ground source heat pump fitted, it is essential that heat loss calculation is performed to the highest standard. This is because if heat loss is miscalculated then you can end up paying for an oversized heat pump or, if insulation is insufficient, you may end up in a cold house.

If the assessment isn’t completed properly it can create real issues down the line, producing high electricity bills and resulting in malfunctions. That’s why it’s so important that heat loss is calculated accurately.

Energy efficiency in UK homes

In the UK, the efficiency of a home varies greatly depending on the style, age and design of the property.

There are many old properties in the UK and although they might be beautiful, they often have very poor heating efficiency.

Many homes in use today were built in the mid-90s and still haven’t been brought up to the insulation standards required. In fact, UK housing is some of the oldest and worst insulated housing in Europe, with 38% of homes built before 1946 and only 15% since the 1990s.

If we dive into the stats, it makes for an interesting read:

Clearly, home insulation is something more homeowners need to think about and calculating heat loss and having an idea of how efficient your home is, is an important part of that.

Heat loss calculator

Calculating heat loss might seem like a complicated process, however, Omni calculators have made it simple for you, by putting together a helpful tool. Simply input your data into the custom fields and find your results.