Walthers Roundhouse

There is a Brick Roundhouse available for Walthers, and I’m considering buying it for my layout. But before I do I want to know a few things about it.
Approximately how big is it, once assembled?
Is it very difficult to build?
And would it be appropriate for steam engines to use it?

They actually have two sizes. The smaller one is about 26" from the center of the turntable to the back wall. The larger one (Modern Roundhouse) is about 30" to the back wall or 32" if you put in the extensions. The smaller one is 14" across at the widest end of the 3 stall configuration and the larger one is 16" across. If you have their catalog they are on pages 451 and 454.

You may also want to look at the Korber Models roundhouse. It is simialr in style, but is made much sturdier and also made in the US and not overseas.

The Korber isn’t as deep as the larger Walthers unfortunately. At 15 1/2", it won’t accept most of my locomotives. On a related note are there any engine houses (not necessarily round houses) that will accept locomotives in the 130’ range? All I’ve been able to find that big is the Walthers with extensions, unless I combine two shorter ones from any manufacturer.

Round houses and steam are synonymous. To the best of my knowledge the only reason diesels used round houses is because they already existed.