Plastics are synthetic polymers, more, or less flammable. Properties to make them suitable to be used more often and are widely used in architecture, to the usual life of human. Architecture is the biggest user of platics. The aim of the diploma thesis is to compare flammability of polymers used in architecture. The selected kinds of polymers such as polyvinylchloride, polystyrene, polyurethane, light-density polyethylene, polypropylene and polymethyl methacrylate were subjects to heat combustion testing in accordance with STN ISO 1210 . Samples were tested by method A and method B. We have obtained the following results by method A: the highest linear burning rate was reach the polyurethane (255,7 mm / min.) And the lowest linear burning rate reach polypropylene (17.5 mm / min). The largest decrease weight we found polyurethane samples (56.6%), the lowest decrease weight was recorded in polystyrene samples (28.3%). By method B, we have reached the following results: the highest linear burning rate was reach by a polyurethane sample (424,5 mm / min) and the lowest linear burning rate was reach by a polypropylene sample (19.97 mm / min). The highest decrease weight was reach in samples of low density polyethylene (90.3%), the lowest decrease weight was reach in polystyrene samples (46.1%). The main accompanying phenomenon in the ignition test was an unpleasant smell in all tested samples.