150mm high, 50mm thick, concrete numbers, Impact Font.
Concrete products and concrete ideas can be found on many websites throughout the internet. Look at Pinterest for some ideas of what can be achieved. Either buy them online or design your own concrete products. Concrete ideas.
Concrete numbers and letters available 150mm high, 200mm high, 250mm high and 300mm high. Note, a 300mm high by 50mm thick character will weigh about 5.5kg+ in a Impact font.
For really big house numbers it might be better to go for faux concrete characters instead. A 600mm high number could be grey limestone coated in a thin layer to keep the weight down and make it transportable. Just an idea to think about.