BUAs and buildings...

[SK-BLitz]

The rules clearly define what BUAs are but also refer to hard buildings (p62).

Are the latter standalone structures, such as an isolated farmhouse or church? Also, if it is a church with a clocktower or is a building with two or more storeys, does this give any height advantage for spotting the enemy?

Finally, if (low profile) troops occupy one of these structures, at what distance are they seen if they don't open fire?

[Big Insect]

The rules clearly define what BUAs are but also refer to hard buildings (p62).

Are the latter standalone structures, such as an isolated farmhouse or church? Also, if it is a church with a clocktower or is a building with two or more storeys, does this give any height advantage for spotting the enemy?

Finally, if (low profile) troops occupy one of these structures, at what distance are they seen if they don't open fire?

> Another one of those ... "it depends" sort of answers Chris 
Visibility into a BUA to spot infantry is 10cms & it would be the same with a Hard Structure* - that is standard. But if they are Concealed - see bottom Page 14 - they are only visible at 5cm (Low profile units) or 10cm (Average profile). Even if the units are seen, hitting them is quite another matter 
*seeing is only partly about the strength/density of the structure - a corrugated iron shanty town on a single level, can actually be harder to spot infantry in than a multi-storey office block. It is often the way that troops are behaving that will give them away. Sun glinting off a binocular lens, dust from a dislodged brick falling, or even the lack of birds on a particular building or snow melted on a roof, where a camp-stove has warmed the room etc.etc.

Generally Chris - at 6 or 10mm/15mm scale the rules work best on the basis of BUAs. You can state that your BUA is a high area terrain piece, so has some buildings with adequate height to gain a height advantage to spotters, but that is probably more granular than was actually intended.

The separate buildings piece was included to satisfy 20mm/28mm scale gamers, where there might be a need for more specific individual structures. There is a whole section on Hard Buildings at the top of Page 85. (I cannot find the reference on Page 62 though?)

It is up to you if you want to play this rule for specific structures, alongside the BUA principle.
Multi-storey car parks are also usually good 'hard buildings'.
I'd agree that large tower blocks, church towers, even raised sections of modern motorways/freeways might give your observers a +1 height advantage. But spotting from a church tower is actually not that easy, especially if it is one on the Continent, where steeples are generally the order of the day.

Hope that helps?