Gorter Group manufactures steel access hatches and closure constructions in Schagen. It holds three current KOMO attesten under BRL 3241, brand- en/of rookwerende puien, ramen en deuren, issued by SKG-IKOB — SKG.0372.0489.08.NL for the RHTEI steel roof-hatch construction classified EI 120, plus SKG.0372.0488.08.NL and SKG.0372.0457.07.NL, all valid to 2029 — supported by European Technical Assessments ETA-19/0680, ETA-18/0831 and ETA-18/0287 for roof, floor, wall and ceiling hatches.