{"id":20285,"date":"2025-01-20T09:11:36","date_gmt":"2025-01-20T07:11:36","guid":{"rendered":"https:\/\/www.klicarquitectos.com\/best-thermal-insulation-external-walls\/"},"modified":"2026-09-06T02:55:33","modified_gmt":"2026-09-06T00:55:33","slug":"best-thermal-insulation-external-walls","status":"publish","type":"post","link":"https:\/\/www.klicarquitectos.com\/en\/best-thermal-insulation-external-walls\/","title":{"rendered":"The Best Thermal Insulation for External Walls: XPS and SATE Explained"},"content":{"rendered":"

For external walls, the insulation that usually performs best is extruded polystyrene (XPS)<\/strong>: high thermal resistance, it barely takes on water, and it holds its shape for decades. That combination is why XPS turns up not only on fa\u00e7ades but also on roofs, floors and foundations. Boards such as the URSA XPS F N RG I are a common choice here for exactly that reason \u2014 solid thermal performance in a panel that copes with damp.<\/p>\n

Choosing the best thermal insulation for external walls<\/strong> matters more on the Costa del Sol than most British buyers expect. The problem here is not only keeping heat in during January; it is keeping it out in August. Whether it is a detached house<\/a> inland or a flat near the seafront, the first thing we look at as an architecture practice in M\u00e1laga<\/a> is the building itself: how the walls are built, which way they face, and what state the render is in. That is what decides the sensible option and the budget, not the brochure.<\/p>\n

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Thermal insulation: the materials and what they are good for<\/h2>\n

A thermal insulator is simply a construction material that slows the transfer of heat through whatever it is fitted into. Fit it on the outside and the whole wall works with you instead of against you.<\/p>\n

External insulation has three parts: the insulation itself, the fixings, and the finish. The boards are bonded to the wall with adhesive and mechanical fixings, and the system is then closed with a render coat. That finish is not only technical \u2014 it is also how the building looks, so the same job that cuts your bills can bring a tired 1970s block back up to date.<\/p>\n

To judge which insulation is right, look at four things:<\/p>\n