The Ultimate Guide to Solid Wall Insulation

You might have thought about insulating your cavity walls to save money on your heating bills. But did you know that solid walls can be insulated too? In case you didn’t realize, solid walls can leak as much as 45% of the heat from your home – so insulating them makes a lot of sense.

What is solid wall insulation?

Solid wall insulation is a method to reduce heat loss from buildings with solid walls. Unlike cavity walls, which have a space between two layers, solid walls are single layers and can let through a lot of heat. By adding insulation, either internally or externally, you can significantly improve your home’s energy efficiency, keeping it warmer in winter and cooler in summer. The insulation material acts as a barrier, trapping heat inside during the winter and keeping it out during the summer, thus saving you money on energy bills and making your home more comfortable.

Why Insulate Solid Walls?

Solid walls are a significant source of heat loss. By insulating them, you can drastically reduce energy waste, lower your heating bills, and improve the overall comfort of your home. Beyond financial savings, it also contributes to a more sustainable and environmentally friendly home by reducing carbon emissions.

Types of Solid Wall Insulation:

Internal Wall Insulation:

  • Description: This method involves adding insulation material to the interior side of your walls.
  • Process: Generally cheaper and less disruptive to the building’s external appearance. Good for preserving the character of historic or aesthetically important buildings.
  • Construction: It slightly reduces the internal space of rooms and may require adjustments to internal fixtures like electrical outlets.

External Wall Insulation:

  • Description:
    This technique involves applying insulation to the exterior walls and covering it with a protective render or cladding.
  • Process: Improves the exterior appearance of your home and increases the thermal mass of the building, which can aid in temperature regulation.
  • Construction: More expensive and may require planning permission. It can be disruptive to the appearance if not carefully planned.

Benefits of internal solid wall insulation

  • Energy Efficiency: By insulating your walls from the inside, you trap more heat during the winter and keep your home cooler in the summer. This means your heating and cooling systems won’t have to work as hard, reducing energy consumption.
  • Cost Savings: Lower energy usage translates to lower utility bills. Over time, the savings can more than pay for the initial insulation costs.
  • Aesthetic Preservation: Internal insulation keeps the exterior of your home unchanged. Ideal for period properties or buildings with unique architectural features, it helps maintain your home’s historic charm while modernizing its energy efficiency.
  • Noise Reduction: Insulating your walls can also dampen noise from outside, creating a quieter and more peaceful living environment.
  • Ease of Installation: Compared to external insulation, internal options are less disruptive. No need for scaffolding, and it’s easier to manage in flats or multi-unit buildings where external changes aren’t feasible.

What are the disadvantages of internal solid wall insulation?

  • Reduced Room Space: Adding insulation on the inside reduces the floor area of your rooms. Depending on the thickness of the insulation, this might be quite noticeable.
  • Disruption During Installation: The installation process can be disruptive as it involves removing and replacing plaster, skirting boards, and any built-in furniture.
  • Moisture Management: If not properly installed, internal insulation can lead to moisture issues within the walls, which can cause mold and dampness.
  • Cost: While generally cheaper than external insulation, it’s still a significant investment and might not be the most cost-effective option for all homes.
  • Aesthetic Changes Inside: It might change the look of your interior, especially if you have period features like cornices or decorative moldings that are difficult to replace.

Benefits of External Solid Wall Insulation:

  • Energy Efficiency: Significantly reduces heat loss through your walls, leading to better temperature regulation and lower energy bills.
  • Weather Protection: Adds an extra layer to your home, shielding it from rain, wind, and other harsh weather conditions.
  • Increased Property Value: Boosts the market value of your home by enhancing its energy efficiency and exterior appearance.
  • No Internal Space Loss: Unlike internal insulation, external insulation doesn’t take up any interior space, preserving your room size.
  • Improved Aesthetics: Can improve the look of your home’s exterior, providing a fresh facade and increasing curb appeal.

What are the disadvantages of external insulation?

  • Higher Initial Cost: More expensive than internal insulation due to materials and labor, especially for larger properties.
  • You might need to get planning permission, so check with your local council
  • Planning Permissions: Sometimes requires planning permission, particularly in conservation areas or for listed buildings.
  • Potential for Thermal Bridging: If not properly installed, it can lead to thermal bridging, which can reduce the effectiveness of the insulation.
  • Aesthetic Constraints: Might not be suitable for all properties, especially those with unique or historic facades that you don’t want to alter.

Solid wall insulation costs:

How much does internal solid wall insulation cost?

The cost of internal solid wall insulation can vary based on factors like the size of your home and the specific materials used. Generally, for a typical 3-bedroom, semi-detached house in Great Britain, you can expect the cost to be around £7,500.

Keep in mind that labor costs can make up to 60% of the total expense, and prices can range from £40 to £50 per square meter, potentially reaching over £100 per square meter if a new stud wall is needed.

It’s a significant investment, but the energy savings and increased comfort can make it worthwhile. Are you considering this for your home?

How much does internal solid wall insulation cost?

The cost of external solid wall insulation can vary depending on factors like the size of your property and the materials used. Here’s a general idea: