Panel comprising: • a first woven fabric comprising filamentary elements, referred to as warp elements, which are substantially parallel to one another and extend in a direction referred to as the warp direction, which constitutes a first main direction of the first woven fabric, filamentary elements, referred to as weft elements, which are substantially parallel to one another and extend in a direction referred to as the weft direction, which constitutes a second main direction of the first woven fabric, different from the first main direction of the first woven fabric; • a second woven fabric comprising filamentary elements, referred to as warp elements, which are substantially parallel to one another and extend in a direction referred to as the warp direction, which constitutes a first main direction of the second woven fabric, second filamentary elements, referred to as weft elements, which are substantially parallel to one another and extend in a direction referred to as the weft direction, which constitutes a second main direction of the second woven fabric, different from the first main direction of the second woven fabric; • a linking structure comprising n filamentary elements linking the first woven fabric to the second woven fabric, each filamentary element comprising at least one filamentary portion, referred to as a stay, extending between the first and second woven fabrics and linking the first woven fabric to the second woven fabric, each stay i having an at-rest length h i and extending from a point of attachment to the first woven fabric to a point of attachment to the second woven fabric; each stay of the linking structure has an at-rest length that is substantially equal to the mean h m of the at-rest lengths of the stays, m representing the total number of stays of the linking structure, in that the first woven fabric and the second woven fabric are non-deformable and in that the panel comprises, between the internal face of the first woven fabric and the internal face of the second woven fabric, a filling material, said filling material being a cement-based foam, characterized in that the linking structure is such that it is unable by itself to support the spacing between the two faces of the panel. • a first woven fabric comprising filamentary elements, referred to as warp elements, which are substantially parallel to one another and extend in a direction referred to as the warp direction, which constitutes a first main direction of the first woven fabric, filamentary elements, referred to as weft elements, which are substantially parallel to one another and extend in a direction referred to as the weft direction, which constitutes a second main direction of the first woven fabric, different from the first main direction of the first woven fabric; • a second woven fabric comprising filamentary elements, referred to as warp elements, which are substantially parallel to one another and extend in a direction referred to as the warp direction, which constitutes a first main direction of the second woven fabric, second filamentary elements, referred to as weft elements, which are substantially parallel to one another and extend in a direction referred to as the weft direction, which constitutes a second main direction of the second woven fabric, different from the first main direction of the second woven fabric; • a linking structure comprising n filamentary elements linking the first woven fabric to the second woven fabric, each filamentary element comprising at least one filamentary portion, referred to as a stay, extending between the first and second woven fabrics and linking the first woven fabric to the second woven fabric, each stay i having an at-rest length h i and extending from a point of attachment to the first woven fabric to a point of attachment to the second woven fabric;