Last sentence: 1) Minisplits control humidity well when the temperatures are not high, but high enough to want a little cooling and dehumidification. A lot of AC systems make a lot of cool, humid air when cycling on and off. 2) What kind of cooling did you have up there before and how well did it work? I can't see anything in your picture. Re. your last post: Cooling works better if placed high on the wall. Heating works better placed low. In a mixed heating and cooling environment any were is a compromise, I am not an HVAC pro so I won't answer your last question authoritatively. The answer will probably be that no one can tell without making detailed observations and calculations. In addition to that, you will have to have some way of adjusting heating and cooling seasonally for a single system to serve a loft like that. With just one set of conditions, it will either be too hot in the summer or too hot in the winter. Check out the possible mini split arrangements on the Toshiba, Mitsubishi and Sanyo web sites.

All the houses on the street are approximately the same size, same layout, same style. 1300 sq ft twins. No room on 1st floor for a full bath. Some have added teeny door-almost-hits-your-knees 1/2 baths with the teeniest sinks you've ever seen off the dining room. A neighbor friend came over to see our master bathroom set-up because she was thinking of doing something similar, but then she decided it would be way too expensive. The plumbing had to be completely reconfigured when the previous owners did this, and they had to create a soffit in the living room for the pipes. They did it because they had contractors in the family who could do it for them and give them a good price. It's generally not an improvement the average homeowner on our street would want to undertake, especially in houses this old. Hope this info helps. This is not a fancy bathroom. Basic ceramic tile floor, home depot-type vanity, tub/shower, toilet. But again, it's there, and it looks decent and clean. I'm trying to figure out how much more over the other house's asking/selling price we can reasonably ask. We'll obviously ask our agent, too. I'm just interested in your opinions. Thanks.

Even if the design and structural plan were free, (and you're risking a LOT working with family/friends without an actual contract in place spelling out exact responsibilities and payments in place) the actual implementation of those plans will be a great deal more than $65 a square foot. Beams are not cheap, and to get the head height needed for code, you're probably going to have to do steel, which has tripled in price in the last couple of years. Steel is hard to deal with, and getting the beams into the location (attic) that you need them may require a crane to bring them in through whatever window access you have. The first floor has to be able to support the additinal weight of living space vs. storage space, and that may mean taking off the lower space's siding or drywall to reinforce the studs. That also leads to the foundation being only poured for a single story in the beginning and maybe needing reinforcing for second story living space. That will require excavation and additional concrete pours and on site supervision by the engineer who designs it. Don't forget that you will need to heat and cool that space. Your home's original heating and cooling is sized to the space of the original home and you're not going to just be able to add on a duct and call it done. The entire system may need to be replaced, or a second complete system added. You'll have to figure out the ductwork runs and where you can place them. YOu'll have to add additional electrical outlets. If your panel isn't already 200 amps with plenty of open slots with which to add, you may have to upgrade your panel. You'll have to figure out how to insulate an awkward space with minimal room for insulation. Spray inulation would be the best, but it's the most expensive. THe roof ventilation either needs to be reconfigured or design eliminated by a professional familiar with closed system insulation roofs. Doing otherwise will lead to premature shingle failure for your home. If you're ever thinking of adding a bathroom space up there, the rough plumbing should be designed and implemented now. Retrofitting will be a lot more expensive. Don't forget permits and inspection fees. There's a LOT more too it than just slapping up drywall and moving in.

You describe that your one story home is performing satisfactorily on the fill conditions of your site. The challenge of adding a second story, to your existing one story home is two fold: 1) The foundations may not be adequate for a two story load; 2) The added weight of a one-story, plus a two-story load, may create soil stability issues. Another alternative, if size of your site will permit, is to add a one story addition with appropriate foundations, in lieu of a second story addition over your existing first floor. The two common types of foundations for fill and expansive soils are: 1) Pier and grade beam, and ; 2) Raft or mat slab. Have you checked with your local jurisdiction to see what they will require in the way of design and engineering calculations for your particular site conditions? Often local jurisdictions have significant regulatory requirements based on existing soils and site conditions. I'd check with them (if you have not) to see if your project is feasible, or what alternatives may be possible. Good luck!