A Little Two Bedroom With Little Wasted Space.

You must understand that the designs I am putting forth are meant to be jumping off places.  They are meant to make you think.  What can you live with?  How much can you reduce?  What modifications would you do?  Can you really live with flat storage under platform beds instead of closets and tiny refrigerators?

It seems to me that designers/architects get paid by the number of lines they make on the blueprint.  In Europe, the houses tend to have no closets(many have caves and storerooms) for storage.  People tend to use free standing furniture instead of built in.  There is so much storage under a bed(beds tend to be higher off the floor these days than when I was a kid.) so it only makes sense to ditch the plastic bins and plastic garbage bags, and build a simple cabinet under the bed with large drawers on good heavy duty full extension slides.  Window seats, and dining nooks in bay windows all need to be hollow chests with hinged covers.  All the internal walls of a building can hold shelves or cabinets inside the fabric of the wall.
Lifestyle will also need to be altered.  Excess must be gotten rid of.  Old clothing must go, especially if it does not fit anymore.  Clothing that is wearable without being hung up should be favored over more temperamental clothes.
Also, it is not necessary to have ten changes of sheets and three hundred towels. 
Remember too that it is necessary to drill holes in chests where condensation may collect inside, and then you need to provide repellant for bugs and rodents.  Possibly the holes would benefit from screen on the inside, especially the screening that has the heavy reinforcement wires meshed into it.

I am thinking of a house perhaps a little larger than some of the others discussed, but still very compact and on one level.  Also, I am trying to avoid space wasters like hallways etc.
The basic plan is meant to give plenty of light from south facing glass, for beauty, comfort and for solar gain.  Attic space should be set up for storage, with access through ceilings.
I wanted too, to place all the potential wet areas of the house very close together to make construction as cheap as possible.
I seem to see pretty good French doors or slider units in the discount houses along route one in Massachusetts and finding three the same or a single larger and two slightly smaller or different design ones seems to be a distinct possibility at a reasonable cost.
A double square building, one in front of the other will contain from back to front, seven feet of bath, five feet of kitchen and 12 feet of living space.  On either side, and connecting to "Jack and Jill" type doors to the bath, there would be two more twelve foot squares for bedrooms,  The south facing walls in the living space and two bedrooms would be glass doors of some kind.  East and west would have generous, but smaller(perhaps decorative) windows on the east and west walls.  The north walls would have no windows at all, or just decorative windows.  This may be a bit easier to bear with light tubes conducting light from above into the bath and kitchen.  I am assuming that one would rather live cheaply with no windows in those rooms than worry about natural light in a room that does not require it and a second one that derives plenty of light from the adjoining living space.
Of course, you could ignore my advice and put a nice window in the bath, but make it a good one that will save energy.  To take my design to excess, continue the roof on the north side, almost to the ground, insulating the north side of the house from north winds and providing general storage across the entire length of the house.
I am just doing a bare drawing of the house, allowing you to use the construction methods discussed elsewhere.
Across the front of the house, there would be, from left to right, a set of glass doors as big as you can afford, a smaller set of windows or doors facing west, a south facing set of glass doors, an east facing set like the west windows, and another large set of glass doors.  Smaller glass on the east and west would still give you some solar gain, but the lesser amount of sun and lots of inefficient glass would net out at a loss in heat.  Really great drapes would allow less heat loss though.  Making the side windows non functioning, double or triple pane, stationary panels would reduce air infiltration as well. Dark floors anywhere the glass lets in sun will increase the heat gain.
Another option is to do super efficient stationery panels on the south side of all the spaces, and put super efficient doors on the east and west along with stationery panels.
The total square footage of the building would be around 576 square feet, assuming that you can be creative with clothing storage.  If you feel cramped with this, you could easily increase all of the squares to 16 x 16, or just the bedrooms to 16 x 16.  The square footage would be 1024 and 800 square feet respectively.  You could easily set up some normal closets with the extra space.
Along with the solar gain from the front doors, this long narrow house would provide plenty of south facing roof to mount solar panels.  As with the other houses I have posted, I recommend a pergola across the front of the house to shade the glass with deciduous vines, and deciduous trees planted across the front of the house would shade a deck and parts of the roof (If there are no solar panels) to help control the summer sun.  Solar panels, slightly off the surface of the roof would also provide some shade for the roof.
My kitchen space would have my favorite partition between the kitchen and living space of just a couple of columns supporting a large archway.  Alternatively, I would perhaps put in a drape from wall to wall, or a folding accordion door or glass doors opening the kitchen to the living room as much as possible.  You could also just do nothing at all. There does not need to be any support above if trusses are used to support the roof, with contact with a supporting wall along the bath kitchen wall, and a beam across the living space where the bedroom walls attach to the living space walls.  Another beam across the living space would give very complete support. 
You would just have the kitchen along the back wall of the living space.  The twelve feet or so of wall space would be plenty for cabinets and all the appliances necessary.  This is the time to decide if the European norm of under counter refrigerators is for you.  A rustic dining table would be good for an island, or extra work space for the kitchen, without intruding on the living space.

You might also think about the ridge of the roof running across the 12 foot mark, from east to west.  This would mean that you could put in clerestory windows in the bedrooms, above the doors, and the roof would fall away to the north and have no south facing slope.  That would also mean that the entire burden of solar panels would be on the living room roof on the south side.  If the area is sufficient for your needs, then great.  A solar panel contractor will give you some advice on this.  Beware of contractors trying to sell panels though.  Perhaps it would be best to hire an independent consultant rather than a salesman. 
This house would be no GREAT beauty, except from the front, but we are after efficiency and affordability rather than just beauty.