External Light Well Material

[rab2379]

Hi.

I live in a mews house, and I'm planning a basement excavation. I dont own the land outside the footprint of the house. So, I'm creating light through internal light wells.
The land infront of my house is a highway road which I use to bring my car into my internal garage. The council seem to agree in prinicpal to creating an external light well infront of the house, but have stated the following:

"We would require your light well or cellar to be covered with a solid surface (not a grating) which would be strong enough to take a vehicle."
Can any one suggest a strong enough material that would allow this? And allow light into the basement through the light well?

Thanks.

Rab.