additions alterations angled angles building building-construction building-site building-work construction construction-site construction-work danger development height high industrial metal-work patterned patterns pipes reinforced reinforcing safe safety scaffolding secure security steel steel-scaffolding tall work architecture building work construction work dust protection facade metal work railing rails safety mesh scaffold steel scaffolding white mesh construction helmet sacfety line safety harness safety helmet welder welders welding workmen crane greyscale building construction construction sites cranes heights ladders carpark multi-storey multi-storey carpark bricks brickwork builders-lift buildings construction-lift home house ladder lift second-storey second-story suburban two-storey two-story urban wall walls