Scaffold

An open standard for designing and optimizing plans for real-world homes.

Purpose: To provide anyone with the necessary knowledge to build their own home. Concretely, the intent with Scaffold is the following:

1. To define an open standard for designing homes in 3D-modelling software.
2. To provide localized collections of pre-modelled 3D components.
3. To offer digital tools for construction planning and material optimization.
4. To act as a hub for sharing home designs.
5. To establish a knowledge base for home building.

Scaffold is primarily intended for tiny-house homes, but scales to projects of any size.

Read more about the motivation of this project

The barrier-of-entry for building a home is incredibly high. Traditionally, to design and build a home that is up-to-code and suitable for year-round dwelling, one needs degrees in carpentry, electrics and plumbing, or a lifetime of practical DIY experience and solid know-how. In any case, many months of dedicated research is unavoidable.

Couple these facts with the absolutely ludicrous state of the global housing market, the prospect of ever owning one's own home becomes vanishingly small.

To provide a competitive alternative to the housing market, the barrier-of-entry for home building must be lowered all the way to the ground floor. This project aims to do this through providing complete, step-by-step home blueprints that assumes no prior knowledge on part of the reader.

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Shortcuts: Workflow | 3D-Modelling | Component Lists | Scaffold.py | Showcase | Contribute

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Workflow

For the ones interested in designing their own home using this repository, the recommended workflow is as follows:

1. Build a 3D model of your home using the components in a starter file.
2. Use the model to compile a components list in the specified csv format.
3. Find or compile a stock list that applies to the area in which you live.
4. Use the scaffold library to generate shopping lists, cutting diagrams and estimates.

For anyone interested in building a home that has already been designed, simply browse the showcase section and download a blueprint.

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3D-Modelling

Why invest time into modelling my entire home?

There are numerous advantages to modelling your home digitally before ever starting to the build process. These are but a few:

• When you have a model, iterating on ideas and making changes is extremely simple and will cost nothing. You are free to try out different layouts, materials and sizes.
• Communicating your ideas to others that will be involved in the build process becomes as simple as showing them the model. The risk of misunderstandings is reduced to near-zero.
• With a finished model, you will have every single length and angle measurement beforehand. Using the provided tools, you can plan every single cut before ever touching a saw. This allows you to optimize both the build process and material utiliization, reducing both the impact on the environment and your wallet.
• The advantages that are listed above will make obtaining planning permissions much more feasible.

Modelling Software:
Any modelling tool capable of assigning geometry into components, groups, and assigning tags, is suitable for home modelling. SketchUp is very good option, as it is extremely intuitive and available online, free-of-charge (though not FOSS).

Model Structure

The recommended structuring of models is illustrated below with an example:

My_home
    module_01:1st_floor
        assembly_01:floor
            board_45_195_2120
            sheet_12_1220_2440
            insulation_195_565_2120
            ...
        assembly_02:north_wall
            board_45_195_2120
            window_20_1000_1000
            outlet
            ...
        ...
    module_02:2nd_floor
        assembly_03:east_gable
            ...
        ...
    module_03:roof
        ...
    ...

• A module is a group of assemblies. An assembly is a group of components. Modules and assemblies should be tagged as module_xx:name and assembly_xx:name.
• A component is a basic building block, and should be be tagged with their category, e.g. a category_xx:board and category:sheathing.
• Variable-size components like boards and sheets should include dimensions in their name, e.g. board_thickness_width_length.
• A component can be made up of other components, e.g. several electrical switch types share standard components like fastening.

Note: Component models need only be as complex as is needed to convey structure and function.

Starters

Starters are files that includes components from which fully realistic homes can be modelled. Starters will be in continuous development. The first starter will be a SketchUp file that uses the metric system and standard components available in Denmark (use this as a reference for how to structure other starters).

Naming: starter_[country_code]_[unit_system].[file_extension].

File	Preview
starter_dk_metric.skp includes Lauritz Knudsen (Scheider Electrics) basic components. Plumbing components and other commonly used building materials are coming, including commercially available solar panel systems.

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Component Lists

To take full advantage of having a model of our projects, we must extract data from it. Once a model has been completed, we use it to compile a list of required components as a csv file.

Below is an explanation of such a "components.csv" file.

Components.csv

Header:category;material;module;assembly;uses;count;thickness;width;length;slope;var_dims

Columns	Explanation
category	Arbitrary category description, e.g. board, sheathing, insulation, etc.
material	Arbitrary material description, e.g. untreated pine, galvanized steel, etc.
module	Location in structure, e.g. 1st floor, 2nd floor, attic etc.
assembly	Location in module, e.g. floor, north wall, inner wall, etc.
uses	What component is used for, e.g. joist, stud, inner sheathing, etc.
count	Simply the number of identical components to avoid repeating lines
thickness	Typically the shortest dimension of the component.
width	Typically the second shortest dimension of the component.
length	Typically the longest dimension of the component.
slope	The angle of the cut into the stock to produce this component
var_dims	The number of variable dimensions of the stock, e.g. boards have 1, sheets have 2.

To take advantage of this components list, we also need a list of commercially available (off-the-shelf) stock components, e.g. lumber of standardized dimensions, etc. since it is not possible to purchase construction components with specific dimensions.

Below is the explanation of the structure of such a "stock.csv" file.

Stock.csv

Header:category;material;thickness;width;length;count;unit_cost;norm_cost;density;retailer;load;var_dims

Columns	Explanation
category	Arbitrary category description, e.g. board, sheathing, insulation, etc.
material	Arbitrary material description, e.g. untreated pine, galvanized steel, etc.
count	Simply the number of identical components to avoid repeating lines
thickness	Typically the shortest dimension of the component.
width	Typically the second shortest dimension of the component.
length	Typically the longest dimension of the component.
count	The count of individual components in one unit, e.g. 20-pack nails.
unit_cost	The cost of one of these stock items/packs.
norm_cost	The normalized cost, e.g. eur/m, usd/m^2, etc.
density	The mass per volume, e.g. kg/m^3.
retailer	Where the entry data is from, i.e. where this stock can be bought.
load	Whether the stock is rated for load-bearing, 0 for no, 1 for yes.
var_dims	The number of variable dimensions of the stock, e.g. boards have 1, sheets have 2.

The components and stock files can have any name, but the stock-file's name is encouraged to follow the pattern [localization]_[unit-system]_[...].csv, e.g. dk_metric.csv or us_imperial.csv, such that they can be shared.

Note:

• The names of the csv files are irrelevant to the program.
• Columns are semicolon-separated by default, but is settable using the sep= parameter.
• The order of the columns is irrelevant to the program, but the shown order is encouraged.
• Blank lines and # comments are ignored by the program, so can be used to increase readability.
• The var_dims number determines the dimensionality of the applied packing algorithm.

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The Scaffold Library

Using the components.csv and stock.csv files together with the Scaffold python library, we can generate stock shopping lists, cutting diagrams and extremely accurate estimates of costs, volumes and masses of constructions, both in total and for individual modules, assemblies, categories and any combinations thereof.

# Import the Plan class from the scaffold library.
from scaffold import Plan

# Load in components and available stock.
plan = Plan("path/to/components.csv", "path/to/stock.csv")

Input example

components.csv

category;material;module;assembly;uses;count;thickness;width;length;slope;var_dims

# Boards.
board;untreated pine;base;floor;rim joist;2;45;195;4880;0;1
board;untreated pine;base;floor;joist;9;45;195;2350;0;1
board;untreated pine;base;floor;blocking;6;45;95;565;0;1
board;untreated pine;base;floor;blocking;2;45;95;542.5;0;1

board;untreated pine;base;north wall;wall plate;2;45;195;4880;0;1
board;untreated pine;base;north wall;full stud;4;45;195;2120;0;1
...

# Inner sheathing.
sheathing;plywood;base;floor;inner sheathing;4;15;1220;2440;0;2

sheathing;plywood;base;north wall;inner sheathing;2;12;1220;2210;0;2
sheathing;plywood;base;north wall;inner sheathing;2;12;1025;2210;0;2

sheathing;plywood;base;south wall;inner sheathing;2;12;1025;2210;0;2
sheathing;plywood;base;south wall;inner sheathing;1;12;907;2210;0;2
...

# Outer sheathing.
sheathing;plywood;base;north wall;outer sheathing;4;12;1220;2420;0;2

sheathing;plywood;base;south wall;outer sheathing;2;12;1220;2420;0;2
sheathing;plywood;base;south wall;outer sheathing;1;12;907;2420;0;2
...

stock.csv

category;material;thickness;width;length;count;unit_cost;norm_cost;density;retailer;load;var_dims

# Boards
board;untreated pine;45;45;3000;1;29.25;9.75;450;jemogfix.dk;0;1
board;untreated pine;45;45;4200;1;33.39;7.95;450;lavpristrae.dk;0;1
board;untreated pine;45;45;4800;1;56.38;11.75;450;stark.dk;0;1
board;untreated pine;45;45;5100;1;59.90;11.75;450;stark.dk;0;1
board;untreated pine;45;45;5400;1;63.43;11.75;450;stark.dk;0;1

board;untreated pine;45;70;3000;1;54.95;18.31;450;stark.dk;1;1
board;untreated pine;45;70;3600;1;65.94;18.31;450;stark.dk;1;1
board;untreated pine;45;70;4200;1;76.93;18.31;450;stark.dk;1;1
board;untreated pine;45;70;4800;1;87.91;18.31;450;stark.dk;1;1
board;untreated pine;45;70;5100;1;93.41;18.31;450;stark.dk;1;1
board;untreated pine;45;70;5400;1;98.90;18.31;450;stark.dk;1;1

board;untreated pine;45;95;2400;1;33.48;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;2700;1;37.66;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;3000;1;41.85;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;3600;1;50.23;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;4200;1;58.59;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;4800;1;66.96;13.95;450;lavpristrae.dk;0;1
board;untreated pine;45;95;5100;1;89.50;17.55;450;stark.dk;0;1
board;untreated pine;45;95;5100;1;124.29;24.39;450;stark.dk;1;1
board;untreated pine;45;95;5400;1;94.78;17.55;450;stark.dk;0;1
board;untreated pine;45;95;5400;1;131.70;24.39;450;stark.dk;1;1

board;untreated pine;45;120;3600;1;75.42;20.95;450;lavpristrae.dk;1;1
board;untreated pine;45;120;4200;1;87.99;20.95;450;lavpristrae.dk;1;1
board;untreated pine;45;120;4800;1;100.56;20.95;450;lavpristrae.dk;1;1

board;untreated pine;45;145;3600;1;89.82;24.95;450;lavpristrae.dk;1;1
board;untreated pine;45;145;4200;1;104.80;24.95;450;lavpristrae.dk;1;1
board;untreated pine;45;145;4800;1;119.76;24.95;450;lavpristrae.dk;1;1
board;untreated pine;45;145;5400;1;134.73;24.95;450;lavpristrae.dk;1;1

board;untreated pine;45;195;3600;1;118.62;32.95;450;lavpristrae.dk;1;1
board;untreated pine;45;195;4200;1;138.39;32.95;450;lavpristrae.dk;1;1
board;untreated pine;45;195;4800;1;158.16;32.95;450;lavpristrae.dk;1;1
board;untreated pine;45;195;5400;1;177.93;32.95;450;lavpristrae.dk;1;1

board;untreated pine;45;245;3600;1;154.62;42.95;450;lavpristrae.dk;1;1
board;untreated pine;45;245;4200;1;180.39;42.95;450;lavpristrae.dk;1;1
board;untreated pine;45;245;4800;1;206.16;42.95;450;lavpristrae.dk;1;1
board;untreated pine;45;245;5400;1;231.93;42.95;450;lavpristrae.dk;1;1

board;untreated pine;45;295;3600;1;215.82;59.95;450;lavpristrae.dk;1;1
board;untreated pine;45;295;4200;1;287.76;59.95;450;lavpristrae.dk;1;1

# Sheathing
sheathing;plywood;9;1220;2440;1;249.00;0;460;jemogfix.dk;0;2
sheathing;plywood;12;1220;2440;1;299.00;0;460;jemogfix.dk;0;2
sheathing;plywood;12;1220;2440;1;289.00;0;460;jemogfix.dk;1;2
sheathing;plywood;15;1220;2440;1;349.00;0;460;jemogfix.dk;1;2

# Insulation
insulation;rigid mineral wool;95;600;960;10;169.00;29.34;37;jemogfix.dk;0;2

# Optionally apply filters to the components and/or stock lists.
# Filters are standard Pandas queries.
plan.filter_components("module == 'base' and category == 'board'")
plan.filter_stock("length <= 4800")

# Visualize all components.
components = plan.inspect(combine=True, sort=True, show=True)

Output example

# Pack components into appropriate stock.
packings = plan.pack(show=True, cut_thickness=1)

Output example

# Summarize findings, i.e. cost, volume, mass, stock utilization, etc.
plan.summarize(currency="dkk")

Output example

Summary:
--------
Required stock:
• 16 of 45x45x5400 untreated pine board
  63.43 dkk per 1 unit(s) at stark.dk
  Cost: 1014.88 dkk, Volume: 0.17 m³, Mass: 77.21 kg
  Utilization: 98.07%

• 1 of 45x45x4800 untreated pine board
  56.38 dkk per 1 unit(s) at stark.dk
  Cost: 56.38 dkk, Volume: 0.01 m³, Mass: 4.12 kg
  Utilization: 94.1%

• 27 of 45x95x5400 untreated pine board
  94.78 dkk per 1 unit(s) at stark.dk
  Cost: 2559.06 dkk, Volume: 0.62 m³, Mass: 278.13 kg
  Utilization: 99.16%

• 1 of 45x95x2400 untreated pine board
  33.48 dkk per 1 unit(s) at lavpristrae.dk
  Cost: 33.48 dkk, Volume: 0.01 m³, Mass: 4.18 kg
  Utilization: 90.46%

• 32 of 45x195x5400 untreated pine board
  177.93 dkk per 1 unit(s) at lavpristrae.dk
  Cost: 5693.76 dkk, Volume: 1.43 m³, Mass: 642.66 kg
  Utilization: 94.18%

• 2 of 45x195x4800 untreated pine board
  158.16 dkk per 1 unit(s) at lavpristrae.dk
  Cost: 316.32 dkk, Volume: 0.08 m³, Mass: 35.64 kg
  Utilization: 94.02%

• 42 of 12x1220x2440 plywood sheathing
  299.0 dkk per 1 unit(s) at jemogfix.dk
  Cost: 12558.0 dkk, Volume: 1.33 m³, Mass: 610.52 kg
  Utilization: 88.46%

• 12 of 15x1220x2440 plywood sheathing
  349.0 dkk per 1 unit(s) at jemogfix.dk
  Cost: 4188.0 dkk, Volume: 0.52 m³, Mass: 239.24 kg
  Utilization: 97.06%

• 22 10-packs of 95x600x960 glass wool insulation
  169.0 dkk per 10 unit(s) at jemogfix.dk
  Cost: 3718.0 dkk, Volume: 10.65 m³, Mass: 170.35 kg
  Utilization: 90.92%

Total stock volume: 16.17 m³
Total component volume: 14.81 m³

Total stock mass: 2212.44 kg
Total component mass: 2062.04 kg

Total utilization: 91.62%
Total cost: 30137.88 dkk

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Showcase

The place where home models and their plans are displayed.

The Nano

The Nano

A modular tiny home designed to be on wheels.

The Micro

The Micro

This is a model designed only to be a reference plan for others that wish to contribute with their own plans. It serves to illustrate the idea of building a complete model as one would a real house, i.e. using discrete units of timber, fasteners, etc. It also serves to demonstrate how to organize the model using tags. Model | Materials

Framing and inner sheathing.	Outer sheathing.
Thermal control layer (insulation).	The 1st floor internal layout.
The 2nd floor internal layout.	Basic layouting of utilities.

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Contribute

You can contribute in the following ways:

• Fork a starter and localize it to the commercial standards of your area.
• Use an existing starter to create full home models.
• Review existing models, opening issues, compile material lists, etc.
• Modify or modularize existing models.

All contributions are processed through pull-requests.