A bathroom exhaust fan should be sized to provide a complete exchange of air in 15minutes (4 air exchanges per hour). To compute the fan size you begin by computing the total volume of the room, length x width x height. You stated your bathroom is 5x7 and assuming an 8ft ceiling we get 5x7= 35sq.ft x 8ft height equals a total volume of 280cu.ft. We want the fan to exchange the air four times per hour so we multiply the room volume by 4 to determine the total volume of air to be moved per hour. 280cu.ft x 4 = 1120cu.ft/hr. Now divide the total CFM/hr by 60min/hr to determine the required CFM of the fan. 1120Cu.ft per hour / 60min per hour = 18.66cfm. The purpose of the fan is to insure we remove any residual water vapor in the room after you finish your shower. For optimal performance you should have a fan switch that has a 15 minute delay on break. With this type of switch the fan will start as soon as you turn the switch on, but when your leaving the room you turn the switch off and it will continue to run the fan for another 15 minutes causing one more air exchange before turning the fan off, thus it will provide a maximum reduction of moisture in the air.

There are a lot of misconceptions about tree roots :-) All trees will produce widely spreading root systems - with most mature trees the root system will spread out 2-3 times the height of the tree. Sometimes quite a bit further if soil and water conditions dictate. And the bulk of the root system is contained in the top 12-24" of the soil profile. Also, tree roots do not "tear up" foundations - if the foundation itself is structurally sound - no cracks or crumbling - any tree roots that encounter the solid surface of a foundation wall will simply change directions. Foundation issues only occur if the structure is already compromised and that is typically attributable to settling or soil subsidence, not roots :-) Many trees will develop large roots right under the soil surface that in time will emerge through the lawn or in the soil surrounding them, large growing maples like both silver or reds are just a couple of common examples. This is one of the reasons growing smaller plants under the canopy of these trees is difficult - it is a very rooty location, hard to dig, and those existing roots claim the majority of available nutrients and soil moisture, not to mention the heavy shade these situations produce. Few other plants appreciate those tough conditions. Silver maples are no better or worse than any other large growing maple. They seed heavily - but then so do my native bigleaf maples - and they tend to have a natural branch structure that leads to breakage in high winds or ice storms unless properly pruned/trained (ditto the bigleafs). They are very closely related to red maples and share many of the same characteristics: a preference for moist soils (they share the common names of swamp or water maples), a wide spreading, surface oriented root system, heavy seed production and both are native trees with a very wide natural range. I would not plant either silver or red maples close to inground plumbing/water pipes or near a septic system as their water-loving nature can create problems. Their DNA is so close they are able to hybridize easily, with the resultant Freeman maples (Acer x freemanii) offering the best characteristics of both species. Numerous named forms - cultivars - exist of all three types and all are propagated by grafting.

The sun exposure requirements for Styrax americanus and Halesia species are about the same...full sun to partial shade. The fact that your styrax leaned towards the sun was because that's what plants do, not because of it's sun exposure requirements. Sun exposure requirements are about plant health and vigor, not phototropism. Allegheny chinquapins are susceptible to chestnut blight and are a host for oak wilt.

I did a quick, ugly layout over my floorplan - know it has to be much more accurate, but I think it shows where my questions are coming from. You tile would typically run 90 degrees to your layout.