Over all the site looks very nice. I like the use of colors and especially like your use of photos.I don't believe I would have used frames. They can cause some problems if not used properly. You might want to look at this link to get a good idea of what I mean: http://www.useit.com/alertbox/9612.html
The top and side slices are not lining up quite right.
The Model Location page has some side-to-side scrolling at a resolution of 800x600. It could probably be eliminated by using a smaller font size and/or cutting down on cell widths on the table.
...side-to-side scrolling on Home Designs page.
Do you have a no-frames version? Don't forget meta tags and alternate text for your graphics.
Good job. 
Best wishes,
Sandy
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www.alleghenyweb.com