Heightmap Issues

Hello everyone.

Recently I’ve been attempting to create an external scene while doing this I’ve been hit with the issue of terrain. I would ideally like to use Unreal Engines built in terrain tools, but I need to be spot on accurate with what I am doing, as it is for an architectural visualization.

I’ve tried creating a height map out of the already existing mesh we have made in lightwave using a gradient on the y axis, this isn’t accurate to what’s modeled, another issue I’ve came across is when I actually import it, it isn’t the right size at all, and I can’t figure out how to make it the right size.

If anyone could help that would be greatly appreciated, thank you.