1.0 Viljami

1.1 Introduction

Big dream, tiny home

Viljami is the product of a cold climate Tiny House on Wheels -project called Big dream, tiny home. 1kW heating reaches a 40°C difference to the outside temperature; Viljami's total mass is 2.7 tons and it's towable with a BE licence. Prototype of Viljami was built in 2016 and the structure has been in development since. Viljami contains no fixed electronic or gas installations.

Media releases

1.2 Bureacrazy

Weight and licence

There are four classes of trailer driving licences in Europe (O1-O4); as the weight of the trailer rises, so does the license needed for towing. [1] With a basic drivers license (B) you can tow trailers of class O1 (total mass under 750kg and no breaks). With B/96 you can tow an O2 trailer, but the combined weight of vehicles can't exceed 4.25 tons. BE (so called "little E") allows towing of class 02 with a maximum combination weight of 7 tons (3.5 tons for each vehicle).

Since O2 trailers usually weigh near a ton on their own, the maximum weight of the house and load is 2.5 tons. This is the category Viljami's in with a total mass of 2.7 tons (0.9 tons of trailer and 1.9 tons of house). Exceeding the 3.5 ton mass limit requires a truck or a tractor for towing.


Maximum measurements of the trailer are regulated according to the vehicle type instead of weight; in most Tiny House cases it's the center-axle trailer. The regulation is simple: maximum width of the trailer is 2.6m, height 4.4m and length 12.5m. [4]

For towing wider, higher or longer trailers you need a special transportation permit which needs to be applied separately every time you move the house on a public road. [5] If the width is exceeded, the transport has to have warning vehicles driving before and/or after it (count dependent of the width of transport), which of course costs a ton. Exceeding the height limit is not recommended due to bridge heights and the length limit is pretty much impossible to exceed because of the weight limit.

Registration and inspection

There are three worthy options for registering the Tiny House on Wheels: a recreational trailer, a custom cargo hold and a detachable load. The detachable load means that the house isn't permanently fastened to the trailer and the trailer's registration isn't changed, which is a very tempting option due to it's lack of bureaucracy. The following table compares the traits of the options.

Recreational vehicle Custom Cargo Hold Trailer with breaks
Registration Change inspection sufficient * Change inspection sufficient * -
Inspection interval 2 yrs 2 yrs 2 yrs
Mandatory installations Bunks, chairs, table, a cooker - -
Electricity and gas With proper documentation With proper documentation -
Taxes and insuranses No taxes, traffic insurance mandatory No taxes, traffic insurance mandatory No taxes, traffic insurance mandatory
Trailer body overflow Allowed if solid structure Allowed if solid structure Only length overflow allowed
Additional information - - Load (house) must be detached for inspection, no fixed installations

* Whether the house is permanently attached to the trailer or not, any changes shouldn't be made to the load bearing structure of the trailer (no drilling or welding). Usually this means the large beams (in which the axles are attached to) and the shaft; the type-approval of the trailer expires if the officer decides that the carrying capacity of the structure has been compromised. In any case you should always consult the inspection officer making the registration change and get the plan approved beforehand. Better safe than sorry.

The construction needs to be straight and safe for pedestrians with no sticking sharp objects (drip edges for instance). Weight needs to be balanced above the axis and at in no circumstances should the trailer lift the vehicle.

Gas and electronics

A document regarding gas and electrical installations of a vehicle can be found here. The short version goes: let the professionals do it. What needs to be taken into consideration while building is that the gas needs to be stored separately from the living quarters (either outside or in an airtight cabinet) and with gas appliances there has to be at least two 10*10cm air vents that cannot be closed - one located at the floor level and the other one in ceiling level. Every burner needs to have flame monitoring and the heaters powered with gas need to be sealed in an airtight space with it's own ventilation.

"If you are going to sin, sin against God, not the bureaucracy. God will forgive you but the bureaucracy won't." - Hyman Rickover

1.3 Materials


Tables below list all the materials that compose the current version of Viljami (12/2017). Viljami's plan is available in 3D form at 3D Warehouse. Total mass of these materials is 2.7 tons and they cost roughly 9.2k euros.

a TRAILER Details Quantity Mass
Westmac Boro Atlas
8000*2500*6000mm 1 930kg
b FRAME Details Quantity Mass
Metsä Wood
Kerto-S beam
39*130*3100mm 7 45kg
Metsä Wood
Kerto-S beam
39*100*6100mm 4 45kg
Metsä Wood
Kerto-S beam
39*100*3100mm 14 73kg
Metsä Wood
Kerto-S beam
39*100*2500mm 23 107kg
Metsä Wood
Kerto-S beam
39*50*2500mm 10 25kg
Universal screw 5*70mm 200 -
Bolt and washer M8 70mm 12 -
c DOOR AND WINDOWS Details Quantity Mass
Pihla P500
Patio door
790*2090mm 1 107kg
Pihla Varma
Fixed window
540*2090mm 1 79kg
Pihla Varma
Fixed window
1390*840mm 1 79kg
Frame screw 5*70mm 30 -
Facade plug 14mm 30 -
c INSULATION Details Quantity Mass
Finnfoam FF-PIR
PU board
100*600*2400mm 55m2 190kg
Finnfoam FI-300
XPS board
100*600*2500mm 13m2 45kg
Finnfoam FI-300
XPS board
5*600*2500mm 2m2 4kg
Seam foam 750ml 20 -
Aluminumium tape 50mm*50m 5 -
d ROOFING Details Quantity Mass
Breathing underlay 60m2 1 -
Builders tape 50m 1 -
Sawn spruce board 22*100*6100mm 6 44kg
Sawn spruce lath 22*40*6100mm 6 18kg
Ruukki Classic Silence
Roofing piece
6110mm 6 120kg
Ruukki Classic Silence
Side eaves
3000mm 1 -
Ruukki Classic Silence
End eaves
3000mm 5 -
Ruukki Classic Silence
Top eaves
3000mm 1 -
Ruukki Classic Silence
Fixing screw
4*25mm 100 -
Ruukki Classic Silence
Roofing screw
28mm 100 -
Roofing felt 8m2 1 -
e EXTERIOR Details Quantity Mass
Koskisen Koskistandard
Birch plywood
4*1200*3600mm 9 105kg
Koskisen Koskistandard
Birch plywood
4*1200*3000mm 4 31kg
Koskisen Koskistandard
Birch plywood
9*1200*3000mm 3 28kg
Marine and technical glue 300ml 15 -
Galvanized staple 40mm 2500 -
Pine cover strip 12*42*3600mm 18 14
Pine lipping 40*40/35*3600mm 4 3
Anti-mold agent 10l 1 -
Roofing screw 28mm 100 -
Hinge - 4 -
Latch - 2 -
Ventilation grating 100-125mm 3 -
f INTERIOR Details Quantity Mass
Koskisen Koskistandard
Birch plywood
4*1200*3600mm 2 17kg
Koskisen Koskistandard
Birch plywood
4*1200*3000mm 14 106kg
Koskisen Koskistandard
Birch plywood
9*1200*3000mm 4 48kg
Koskisen Koskistandard
Birch plywood
12*1200*2500mm 5 100kg
Koskisen Koskistandard
Birch plywood
18*1200*3000mm 4 66kg
Dyckert nail 45mm 2500 -
Foam mat 2*1000*1500mm 1 -
Wood floor oil wax 750ml 2 -
Worktop oil wax 500ml 1 -
Birch latch 2*2*3000mm 1 -
Ikea Ekby shelf bracket 6 -
Sheet screw 10mm 200 -
g SANITATION Details Quantity Mass
Waste pipe straight 32*3000mm 2 -
Waste pipe corner 32*32mm 1 -
Waste pipe T-fork 32*32mm 1 -
Waste pipe support bracket 32mm 10 -
Waste pipe reducer piece 50*32mm 1 -
Waste pipe reducer piece 40*32mm 1 -
h FIXTURES Details Quantity Mass
Separett Villa 9010
Dry toilet
700*900*2100mm 1 30kg
Shower stall 700*900*2100mm 1 100kg
Sink 425*520mm 1 10kg

Loose materials

Extension cords, radiators, tour shower, tent stove, Primus, candles, fire safety equipment, hammock. Simple, cheap "camping equipment" that don't need documentation for comfort.

1.4 Partners