Efficient design 20x20

Started by BlueRidge, December 10, 2016, 07:05:17 PM

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BlueRidge


I'm not good at importing photos and drawings, if someone could go to the link and import these for discussion I would be most appreciative.

https://www.houseplans.com/plan/400-square-feet-2-bedrooms-1-bathroom-cottage-house-plans-0-garage-36143

This design looks very efficient, flexible, and uses small sizes of lumber to minimize cost.  Does anyone see problems with the design?

flyingvan



   I'm assuming you like the 'type 2' on the left.

    There are a few things I dislike about it.  First, the plumbing---the bathroom and kitchen are diagonally opposite.  Lot of piping, venting, waiting for hot water.... Also it's kind of odd to have then entry right there at the bedrooms.  Someone knocks on the door---can you hear?  Do you really want to come all the way downstairs to answer the door?  Coming home with groceries, or all your stuff if this is a rental---you have to carry it all upstairs before you can set it down.  I like to get through the door and set stuff down immediately.  How is it heated?  That steep, tall upstairs ceiling will draft warmth far away from the bedrooms, and cold bathrooms are no fun.   Fireplace upstairs makes for a cold downstairs.    Living room above bedroom can make it hard to sleep if some people stay up...  All in all I'd rather switch the upstairs for the downstairs.  Now for the framing---



     What is keeping the weight of the roof from pushing out the walls?  If it's a ridge pole supporting a traditionally framed roof, there's no columns supporting it.  Trusses could work instead but they didn't draw them.  Stairs are too steep.  Eaves are a great idea to keep water away from the base of the house.   There doesn't seem to be any accommodation for  ventilation other than the 'operable skylight', there needs to be good plans for airflow and vapor escape, even on days you'd like to close that skylight.  Very little window area. 

     I'm a huge fan of Sarah Susanka and her rules for small house design--most of which this design does not incorporate.  When you walk in to a small house, it should open up into something larger---your first impression upon entering this is, working left to right---Potty.  Hall.  Stairs.  With minimal windows and the layout, retiring for the evening would look and feel like making your way down into a cold dungeon.

   Unit type 1 is much better, with the incorporated garage.  More windows, living space downstairs, more or less stacked kitchen and bathroom.

Find what you love and let it kill you.



BlueRidge


Thank you flyinvan, just the sort of review I was looking for

Kwillet, thanks for the links, it's hard to imagine a city where these cottages sell for $650K+ and are considered the affordable option for the area.

ChugiakTinkerer

The plumbing in those cottages was the first thing I noticed as well.  An efficient design has the plumbing all in one common wall.  If the kitchen is above the bathroom, or vice versa, then you only need build one 2x6 interior wall to contain the needed water, vent, and drain pipes.  I try not to be too judgmental on aesthetic matters, but to me those houses are ugly as sin.  The 2x4 fascia grid looks utterly impractical to install and maintain resulting in a "look at me" feature that will be very expensive in the long term.  I only raise the point because it seems representative of the overall design, drawn up without much apparent consideration to those costs.

If starting from scratch I would try sketching out a floor plan using blobs to represent each room and then think about the plumbing, electrical, and heat,  Figure out an efficient way to lay those out, then flesh out the doors, windows, etc from there.
My cabin build thread: Alaskan remote 16x28 1.5 story


BlueRidge


I'm with you on the external grid, the links show a more traditional exterior.

MacDonald is an award winning architect, the grid mimicked a famous building nearby, San Francisco if I remember.

MacDonald wrote "Democratic Architecture" and low cost housing has been a "pro bono" part of his skyscraper / commercial architecture business.   He also designed shelters for CA homeless people called "city sleepers" (?).


KWillets

They sell for more than that now, but it's not the structure that's expensive. 

These always catch my eye because they're so out of place for the area.  I can see how they might be good in a setting with open space all around, but if you just compare them to nearby structures you can see how inefficiently they use space.  There's a park just across Steiner there too, so even the garden seems a little superfluous. 

I think they date from a time when the neighborhood was less desirable, so they thought that suburban-style houses might be the ticket.  Nowadays the prices are jacked up because they built things like this instead of denser apartment buildings. 

akwoodchuck

#2 would make a nice walkout basement design with an attached mudroom porch and a full-length sleeping loft over the second floor (attic trusses)...would be all a small family needs.
"The lyf so short, the craft so long to lerne."

ChugiakTinkerer

Quote from: BlueRidge on December 11, 2016, 03:59:59 PM
I'm with you on the external grid, the links show a more traditional exterior.

MacDonald is an award winning architect, the grid mimicked a famous building nearby, San Francisco if I remember.

MacDonald wrote "Democratic Architecture" and low cost housing has been a "pro bono" part of his skyscraper / commercial architecture business.   He also designed shelters for CA homeless people called "city sleepers" (?).

The photo at the link is what I based my comment on.  When I see the architect scraping and painting the weathered trim of that grid I might be convinced.  Until then, I suppose I'll hold the opinion that this design will require more of your precious time to build, paint, and maintain than many other alternative designs.

You would also want to check with your code authority to make sure that the exposed rafter ties are allowed.  The photos depict them halfway up the rafter.  Code requires them no higher than 1/3 of the roof height, and I believe they must be at every rafter, not the spacing shown.  Alternatively you could get an engineer's stamp for any code variances.
My cabin build thread: Alaskan remote 16x28 1.5 story


flyingvan

  I've seen this design somewhere before...

Find what you love and let it kill you.

BlueRidge


Yup, that's the plan.  Build four of those and trade them for a hotel.

BlueRidge



ChugiakTinkerer, I agree, I don't like the grid.  I was more interested in the floor plans.  Supposedly these were designed to minimize construction costs.

NathanS

My personal experience is that lumber for framing is surprisingly not a big expense in terms of total house cost. I think that my entire 20x34 2-story with 8x12 mudroom - all stick framed including roof was in the neighborhood of $5000 in lumber. That doesn't include sheathing or weather barrier - but that is where you start having diverging expenses.

Compare that to the apx $7500 on septic including engineering on sculpting earth.

A 20x20 1.5 story would not be very expensive to frame up. You have to be careful with 1.5 stories though, you may need a ridge beam which is very heavy and goes all the way at the peak of the roof. I believe that was already mentioned in the thread, though.

The nice thing about going narrower - and really, 20' is a bit too wide for this (although doable), but at say 16' you can use regular lumber and need no interior supports.

flyingvan

Find what you love and let it kill you.


ChugiakTinkerer

I live in a two-story structure that is very efficient in the plumbing design.  The living space is laid out so that all the plumbed rooms are fed from one common wall.  The lower floor is a walkout basement with a utility room on one side of the wall and a full bath on the other.  Upstairs is very similar.  The 2x6 wall continues up and encloses all the vent and drain piping.  On the main floor there is a full bath above the utility room and the kitchen on the other side of the wall.

As Nathan mentioned above the lumber for framing is relatively cheap.  A stick-built house goes up fast too, at least the framing of it.  But al the other parts, the parts that turn a structure into a house such as plumbing, heating, and electric service will cost as much or more in time or hired labor.  The point I'm hoping to make clear is that in terms of materials just about every 20x20 house is going to have the same materials cost for lumber.  Regardless of floor plan the cost to erect the frame structure will be all within 10% of each other.  It's the cost of everything else that will make the house affordable or not to build, and if the floor plan doubles the amount of plumbing and heating work that will be required then you're going to eat that cost.

One other thing to keep in mind is whether the house is designed for your climate.  Assuming you are in the Blue Ridge Mountains, there is a very good chance that you're experiencing temperatures far below freezing in the winter.  In San Francisco, not so much.  You'll want houses that are affordable to keep warm in the winter, particularly if you'll be the one paying the heating bill.  Some thought should be given to how much it will cost for heat and/or AC for a ten year period, and work that into your calculations on an affordable design.
My cabin build thread: Alaskan remote 16x28 1.5 story

BlueRidge


Flyingvan,  on the 1.5 story plan.  I've seen the one story, and the full two story version, and now the 1.5 story version of that 20x30 first floor plan.  I need to locate someone who can spec out the differences in cost for each.

BlueRidge


ChugTink,  those are great ideas for reducing costs, thanks

KWillets

By the way, I realized the other night that the gridded versions of those are only half a block from the other ones I posted:  https://www.google.com/maps/@37.7705364,-122.431723,3a,75y,27.02h,87.72t/data=!3m6!1e1!3m4!1soNTQZfTGmNrJn3BEJIUOrg!2e0!7i13312!8i6656

These are the ones that have the 2x4 grid all over the exterior.