Looks like a nice house! You might want to consider cross posting this on either the trees, perennials or shrubs forums depending on where you would most like to go with this... or even the garden design forum.... the Pennsylvania gardening forum is kinda slow for the last year or so.

First thing, you don't necessarily have to keep all your plants against the house, a small tree might work if it's planted 7-8 feet out from the house and you keep an access path between it and the wall of the house. As it grows, trim it up so you can get by. Some possibilities might be a tree sized magnolia, sourwood, heptacodium, kousa dogwood, american dogwood, crape myrtle (check hardiness), a taller/narrow crabapple.... maybe an arborvitae if you want evergreen.

Keep the root ball of whatever you plant slightly above soil level so that it won't drown in the clay.... and give it a nice muich that will break down and lighten up the soil.

You might want to consider some tall ornamental grasses to fill in the yard while other slower things catch up. A nice grouping of miscanthus or feather reed grass might help anchor the house into your lot. I've got more ideas, but that's something to get other ideas flowing!

Thanks, folks! To plantman56, I am a great frequenter of Ashcombe's and other local nurseries, so I know your name well! I think the major issues are (1) fear of making a backbreaking mistake and (2) loving almost everything. I have gotten design help with other parts of the yard but have this idea that I would like to do this little piece myself, just to see what I can make of it. But I get distracted by sales and whatever happens to be wonderful at the moment I'm looking... the graph paper idea sounds very centering, I will try it. Right now am drooling over different viburnums... my Birkwood has been a bust for years but this year decided to be intoxicating and wonderful. Thanks again for your feedback.

The plan will help to control what and how many you purchase. Biggest mistake is to buy one of each. Repetition help to pull the design together. Wheather it is perennials or shrubs.
See link - here is a reason to know you plants before you dig. Altough there are many cultivars that may be smaller - you could be faced with ---- maturing at about 10' tall by 8' wide. Good for a back yard border, or a foundation planting about 9-10 wide. Yes you cna prune, but who has the time to go out each year. Go to the Ashcombes web site and print out their plant list. Good info. on plant size and conditions -- Pick 3 shrubs you like. Repeat a few of the smaller shrubs 4x4 size , fill in with perennials - in groups of 3-5.
Good luck

Here is a link that might be useful: Burkwood Virburnum

I planted two Viburnum Cayuga in the front of the house this week... plant tag said something like 4-8 feet and then other sources say up to 11 feet... ah me! I guess time will prove! The Burkwood v. has grown slowly... wonder if I made some planting error. For the South side of the house, I decided not to do wonderful broadleaf evergreens like boxwood or boxwood-looking holly because they might fry in the winter. I'm stumped for something gorgeous that will enjoy those conditions. More viburnum? Too hot for Limelight hydrangea? Tardiva too big? Would serviceberry do well? Will I ever choose? Five more years of a naked AC compressor, perhaps?

Demeron...I have 4 Limelight hydrangea in the middle of my yard in full sun all day long and they do wonderfully...I also prune them back hard every fall so they dont get too big. I love them because they have flowers all summer long. Have fun planting.

Viburnum Cayuga is a large shrub. Most homes do not have a 8ft x 6ft ( or larger) space to plant shrubs unless it is on the corner. I have seen lots of over planted properties, and after 10 years they are riping out and looking for new smaller plants. Pruning is ok for a while but it can be hard work to prune and dispose of all the branches each year. The Limelight is a great plant , there is a "Little LimeLight" which is 3x4 and will give you the same look with out the pruning. Either Limelight would be great on the side. Although the white flowers next to the white house may either be really nice of they may blend and not show up.

Darn it, you're probably right about the Cayuga. I was squinting at them hard today and they're going to be too close. But if I move them young (next fall!) shouldn't be too backbreaking.

I planted my limelights today! I just need to find something tallish and airy and wonderful that I can plant five feet from the house. Is there a tree I wonder that would be okay that close?

You might enjoy having the Serviceberry you mentioned. It can be a shrub or small tree, has lovely drooping inflorescences in spring, and produces sweet berries, about the same size as a blueberry, which birds love.