Exterior insulation, or EIFS (exterior insulated finish system), is the cladding of choice on many modern buildings and has been around since the 1960’s. You’ve probably seen it without even realizing it—it resembles stucco and is used on commercial, residential and mixed-use buildings, including apartment complexes, hotels, shopping malls, office buildings, hospitals and government facilities.

The exterior insulation uses a polystyrene foam insulation—most commonly expanded or extruded polystyrene (EPS and XPS respectively), that is adhered to the existing substrate of the building and then covered with a decorative base coat, fiberglass mesh embedded in the basecoat and a water-resistant sealant. This system helps increase a building’s R-value while reducing air leakage and enhancing its durability, appearance and maintenance.

Stay Warm, Save Money: A Complete Guide to External Wall Insulation in the UK

There are several different types of EIFS, each with their own advantages and disadvantages. Choosing the right material for your project depends on the design and R-value you are looking to achieve. It’s also important to consider the impact of your choice on the life cycle of the materials and any environmental concerns you may have.

When selecting an insulation material, be sure to factor in the exhaust and intake vents, utility access doors and other details that might need to be incorporated into the wall assembly. It’s essential to have a plan for dealing with these issues in advance so that the work is done correctly.

The continuous insulation also reduces thermal bridging through the framing members, improves building airtightness and increases efficiency. It is often more expensive than other wall construction but pays for itself in energy savings over time. For more information about this topic, visit GBA’s complete library of premium articles on exterior insulation and construction details.