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Renewable Energy

Wall Insulation Types: Solid and Cavity Wall Insulation

A survey conducted by the energy saving trust UK revealed that some 35% of the heat in which your home loses escapes through the walls. This is the reason why most people prefer to insulate them first. However, before choosing insulation services for your property it is imperative to ask yourself ‘what type of wall have I got?

Solid Walls

Most of the solid walls are made up of the UK until the 1930s. By solid, it means that there is no cavity (in form of holes) inside walls. A solid wall’s brick design is recognizable by having lots of border bricks, which look like half-length bricks, in the center of the walls. These are mainly cross bricks, which run from the front to the back of a wall. Hence, the depth of a wall – ignoring any plaster on the interior surface – is a brick’s length, about nine niches.

Cavity Walls

On the other hand, Cavity walls consist of an inner leaf and outer leaf, and a gap in between. The brick pattern shows many more full-length blocks. The measurement or depth of the wall is large, as the majority of cavities measure at least two inches.

An Overview about Cavity and Solid Wall Insulation

Once you have made this decision, you have to focus on the options which you have. The main ones are cavity and solid wall insulation. Find out how the two compare.

Options Overview

Cavity wall insulation involves filling the gap between the inner and outer wall of a house with a material which has a high R-value. Typically mineral wool is used, but homeowners have other options which include foam, beads, and granules. The material has to be installed by a professional. Small holes are drilled on the wall at a distance of around 1 meter. Then the installer uses special equipment to blow in the material.

The other option involves solid panels installed on the exterior walls of the house. The panels are made from a material with a high R-value. These panels require professional installation as well. The panels should be installed when external refurbishment work is done. This can help for bringing the cost down.

Building Structure

The main factor for selecting a particular type of wall insulation is the structure of your house. If your house has walls consisting of two layers with a gap in between them, then this gap can be filled with the material which provides for energy efficiency. If your home has a solid wall with no cavity, then you will have no choice but to go for the installation of panels.

Benefits and Drawbacks

Both cavity and solid wall insulation do their job quite well. While the thickness of the cavity filling is strictly limited, you can select the thickness of the solid panels so that you can get even more effective heat loss reduction. With thicker panels, you will enjoy even better energy efficiency and improved sound insulation as well.

The cost of cavity filling is lower compared to that of installing solid panels. This is primarily due to the simpler and faster installation method. Besides, to get panels installed, you will most likely need planning permission from the local authority. The panels do protect the walls from the elements, but since they are exposed to the weather conditions they become at higher risk of damage. At the same time, the savings which you will generate with the installation of external panels are nearly two times greater than those which you will get with the filling of the wall gap.


Having solid wall insulation could help cut your heating costs by quite a lot. This is because solid walls let more heat escape than cavity walls. However, they can be insulated, either from the inside of the house or even from the outside.


If your house is quite old, then the wall may be solid. New homes are built with cavity walls which have two layers with a small space in between. In comparison, solid walls don’t have any type of gap. Insulating a solid wall can be more expensive than cavity wall insulation, but you should see a huge improvement in your energy costs.


To determine whether you should add insulation or not, you first need to find out how much insulation you already have in your home and where it is. A well-qualified home energy auditor will add an insulation check as a routine part of whole-house energy evaluation. A home energy estimation generally is known as a home energy audit, will also help recognize areas of your home that require air sealing.


To know more about the process you are welcome to contact the experts at Pro Efficiently Solution. Experts over there will not only assist you with the right Professional energy assessments that generally go into great detail to assess your home’s energy use. Our energy auditor will do a room-by-room analysis of your habitation, also they will do a review of your past utility bills. Moreover, you can also lease the benefits of the new green homes grant scheme. As details regarding the new Green Homes Grant emerge, homeowners should hopefully be in a more favorable position to evaluate whether they intend to make any improvements to their assets and if so, which may qualify for funding.