Masonry
Locksmithing, toolmaking
Painting, varnishing, painting
Installation, repair, inspection and testing of electrical equipment
Plumbing, heating
Tinsmithing and body repair
Insulation
Joinery, flooring
Roofing, carpentry
Installation, repair, inspection and testing of gas equipment and filling of gas containers
Manufacture, installation, repair of electrical machinery and apparatus, electronic and telecommunications equipment
Installation, repair and reconstruction of refrigeration equipment and heat pumps
Construction, alteration and removal