Scaling, British English

It may mean "climbing." I suspect the writer likens mock-Tudor mansions, with their steep roofing, to mountains.

Isn't it used in this sense in the US?

No, in context I think it's a participle not a gerund, i.e. an adjective. The houses are scaling; no one is scaling them.

"...picture him swinging...not scaling..."

I think in that context it does means "climbing." When we think of Spiderman, we imagine him swinging through the skyscrapers of New York; we don't picture him climbing the steep roof of some mansion in Surrey.

Ah, got it. Thanks both.

Climbing, either with or without rope(s).

Think #5(Nutrex) is probably right as "scaling up the wall" is not an unusual expression among the Brits to express frustration in not being able to solve very difficult problems.

tribolite, "scaling up the wall" is a very unusual expression, at least among the Brits I grew up with. In fact I've never met it before.