Season 3: Episode 7 - A More Detailed Design
Hi Readers! Due to some issues beyond our control (that we will address in a future blog post), we have experienced some serious delays in Project: Tiny House. The good news is, it is all systems go now (if you follow our instagram, you would be aware that stuff has been happening in the background), and we have a few blogs in the bank, so there should be weekly posts for your reading pleasure for many weeks to come.
In Episode 4, we worked through the first 9 iterations of our design process (now we are up to version 25!!) so lets take a look at the evolution of our design, some of the choices we made (and some that we made and then unmade, only to make again, maybe. Clear?), what we were thinking about, choices we have deliberately not made (which might be covered in a future blog) and the pathway towards what we will eventually have built.
Behold - Version 10 (and Version 9 for comparison)! Adam thinks maybe he should have started numbering 01, 02, or maybe 001, 002 to keep the files in a nice order in the folder... but that is just his inner engineering file folder organisation pedant.
In version 10 it was time to start moving from conceptual to concrete. Preliminary framing design was done to think about how the frames would attach to the trailer, where the windows could go without cutting king studs or introducing weight inefficient cripple studs to the framing design. At all times we are thinking about lightness. Building our perfect Tiny House and having it come in over the road legal weight limit would be a very undesirable outcome.
We played around with the roof pitch direction(s), angle and style a lot, but eventually arrived at a single slope skillion style roof. This roof only requires a single gutter along one short edge, meaning no gutters exceeding the 2.5 m width limit, the roof is all in one plane which makes it much easier to build for the budding DIYer and the shape allows warm air to be directed into the sleeping loft, with ventilation easily achieved.
The entry door migrated from the side to the rear of the lounge area (Still VSB1 compliant), as the protruding wheel guards mean the scope to modify the location of the door on the side is very limited. And now the couch can point at the TV we thought we would have. There is a window in the shower (no National Construction Code for tiny houses!) and a Natures Head Composting Toilet. One of the useful things about sketchup is that the online 3d warehouse has loads of existing models you can drop in for free, rather than spending your own time and effort to draw things.
Version 11. Here is an idea - in our quest to be fossil fuel free, lets have a wood fired stove, oven and hot water unit. That is designed for a full sized house. And weighs 192 kg. You will see that the Bakeheart hangs around for quite a few design iterations, until we actually went and looked at one in a shop in Hobart and the intersection of size, weight, expensive and oversized became more apparent.
In Version 12 we started thinking about how our tiny would interact with an external decking space while still being easy to hook up and drive away. The kitchen got a little more fleshed out with an under the bench washing machine and we drew in a volume box for our blender, started thinking about headroom above the bed in the sleeping loft and drew in some yoga mats to see if we could both use the space for exercise at the same time. The roof framing became simplified after some careful checking of AS 1684 and some wind loading estimates for both stationary and an on-the-road tiny house.
Here is an important place for an aside - if you are not a Structural Engineer, or at least not technically and mathematically proficient enough to read, interpret and calculate wind loadings on your tiny house, and if your framing and bracing design will handle your expected conditions, both where you will park it and while it is under tow on an unexpectedly blustery day, then please, please, please, pay the money to consult an expert who can do the calculations for you. Yes, a Tiny House is not a dwelling under the building code, but you also do not want your home flipping over or collapsing. Note that you should also consider the case where you have framed and clad your tiny, making a large wind catching surface area, but have not installed any interior components, making it much lighter and less resistant to overturning. You might find that ballasting, tying down or otherwise bracing the tiny during construction and/or parking is prudent. Or perhaps you need to build inside a shed.
Back to our regular programming...
Version 13 sees us thinking about sink location, plumbing and how the stairs with integrated storage might work to be functional, visually appealing and structurally sound. The washing machine starts getting moved around to try and find the optimal balance of convenience, plumbing efficiency and trailer weight distribution.
SAFETY NOTE 2:
Balance. The weight pressing down on the tow ball should be around 10% of the weight of the trailer. The see saw fulcrum of the wheels are set slightly closer to the rear of the trailer to aid this, but you will notice that our tiny will be a little front heavy as there is more framing, cladding and stuff up front. Locations of appliances and equipment are carefully considered in the context of the moment applied about the centre of the suspension system of the trailer. At the moment (giggle) we have a plan to install our batteries and grey water / ballast tank to the rear which can be variably located / filled to adjust the weight distribution.
Version 14 brings about realignment of all the studs to suit minimal cutting (i.e. no cutting) of 1200 x 2400 bracing ply sheets when we do our sheathing of the frames. During design we think a lot about ease of construction as well as how we want the space to work. The door has also shuffled over to the edge of the rear wall, making the wall space much more versatile adjacent.
In version 15 we started to thin about the exterior cladding of our tiny. We sold our TV (that we were not really using anyway) and decided a nice big picture window would be a better thing to stare at on the couch. We are splashing out for a nice hardwood lining board for the lower part of the walls and a lighter weight colourbond metal roofing/cladding higher up. We started out with a Trimdek profile, aligned vertically, but that was abandoned (can you guess why?) as you will see in a later design in favour of... something else. Our lounge design is now a set of four reconfigurable boxes in a semi-default L shape that we can move around and store light weight things in.
The eagle eyes amongst you will see we started to annotate the various shelves and cupboards to think about what might be stored where. One of the things we didn't like when it cropped up in the tiny house tour videos were when people purchased a standard design, or didn't think enough about what they wanted to still own and had empty drawers or cupboards and laughingly joked they had too much storage. Empty drawers and cupboards are unnecessary material costs, labour time and weight. Our goal is to have an efficiently designed space that feels voluminous while being tiny.
Version 16 sees us playing around with colours of colorbond (can they not just put a U in for the Australian market, please?). There are a lot of little changes and refinements to the bathroom wall position and interior cabinetry.
In Version 17 we started to extend the exterior design to the other walls of the tiny, and thinking very very hard about the detail for the connection between wall top plate, roof rafter, combination second top plate / edge purlin truss (sort of) and the roof bracing, insulation and batten system. There is a lot going on at the top of each wall, so thinking carefully about the connections through the lenses of functional strength, ease of constructability, interactions with other components and maintenance of thermal envelope (insulation) is important.
The sleeping loft gets some more thought with longer windows going in.
Version 18 has us mostly figuring out the external cladding and roof. Flashings for windows and edges are thought about but not shown yet. Detailing window reveals is a problem to think about too. The list gets shorter and longer at the same time.
Version 19 has a range hood over the cooking area with some integrated cabinetry. The important question of 'Can a Guitar hang off a wall?' is answered in the affirmative. We start to think about a table surface, what it might be made of and how it might fold, attach and be reconfigurable for multiple functions and locations including dining table and picture window breakfast bar.
Phew! There is even more design iteration from here, but that is probably more than enough for this blog. See a change we didn't talk about? Or something that doesn't make sense? Or something dangerous? We would love to get your feedback below. Feel free to ask any questions you like, and we will do our best to promptly reply.
Next week we will go on a tip shopping and garage sale-ing adventure and talk about upcycled, recycled and reclaimed materials. Stay tuned!
All our Love,
Adam and Ruth,
Foraging for Vegan Treats
Season 3 Statistics:
Mortgage purchase attempts: 2
Funds raised through selling stuff we were not using: $700
Tiny House University Units Completed: 37
Land Rover For Sale Gumtree Ads Bookmarked: 11
Working weight estimate: 3030 kg
Working cost estimate (spent/total): $6 367/$60 342
Tiny houses we have been inside: 2
Tassie Short Walks Completed: 21/60
Tiny House design hours estimate: 120