Glossary
365-Day Rule A system for thinning out material possessions in which any item that hasn’t been used within a year gets placed into a pile for potential discard/giveaway.
ABS A plastic material used in plumbing applications.
accent wall An area within a larger wall finished differently with intention of creating a visual point of interest.
Actual Cash Value (ACV) coverage An insurance valuation term referring to a property’s worth at current market prices.
Adjustable Rate Mortgage (ARM) A mortgage loan with a periodically adjusted interest rate.
Air admittance valves (AAVs) Code-approved, under-the-sink venting solutions.
alternating tread devices (ATDs) Stairs in which each tread staggers from the next one, allowing for a steeper angle, and thus, less floor space to be taken up in a tiny house.
American National Standards Institute (ANSI) A code development agency that regulates construction standards for RVIA-certified vehicles including Tiny Houses On Wheels.
anchor bolts Bolts that are threaded, rod-welded, or otherwise attached to a trailer that are integral to the safe attachment of wall systems to a frame.
Accessory Dwelling Unit (ADU) A secondary dwelling built on a lot with a primary residence. ADUs can be created within the primary residence, as an addition to an existing house, or can be a totally separate dwelling.
angel investor An individual who provides capital for an investment typically in exchange for ownership equity.
arc fault circuit interrupter (AFCI) An electrical receptacle that breaks a circuit when it detects an electrical arc.
architectural scale A triangular-shaped ruler used to create various scale options on a set of architectural plans.
bottom plate A horizontal framing member placed atop floor sheathing and to which studs are connected.
British Thermal Unit (BTU) The amount of energy needed to raise the temperature of one pound of water by 1 degree Fahrenheit.
builder’s risk insurance This type of insurance provides coverage during the construction process in the case of loss, theft, or damage; it does not include liability coverage.
building codes A set of enforceable standards used to specify safe construction practices.
bump-out A bump-out in a residential structure is an extension in a room that creates a projection in a wall plane. In an RV, it’s a wall that slides out to create additional interior space.
bumper pull trailer The most common form of trailer on the market. The trailer’s tongue attaches to a ball hitch that juts straight out from the towing vehicle’s frame.
butt joint A joint in which two pieces of material meet flush to each other, forming a 90-degree angle to the material in question.
capsule wardrobe A collection of only essential clothing items.
ceiling joist A horizontal framing member connected to the double top plate.
certificate of occupancy (COO) A certificate that gives a homeowner the green light to live in their new residence full time.
closed-cell spray foam Dense spray foam insulation material.
collar tie A horizontal framing member connecting two rafters on a gable roof.
concrete pad and pier foundation A foundation system in which load paths are concentrated over individual columns and footers.
concrete slab on grade A foundation system in which the concrete serves as the foundation and also the flooring base.
contingency fund An emergency fund often built into a loan in case of unexpected expenses during the construction process.
corner stud assembly A vertical framing member placed at corner locations.
cripple stud A vertical framing member installed above and/or below doors, windows, and headers; it never touches the bottom and top plates at the same time.
Department of Transportation (DOT) A federal cabinet department concerned with transportation. The DOT can certify a tiny house as a load on a trailer.
detail section flags Identification flags that give the location and direction of the building detail to which they refer; there are a variety of types, including building section flags, detail flags, and exterior elevation flags.
direct vent heater A heater with a ventilation channel that vents directly to the home’s exterior.
door schedule On architectural plans, a door schedule details the structure’s door information.
dormer A window that projects vertically from a roof, creating a bump-out.
dovetail joint Joints made when two opposing pieces of wood are cut with triangular joints. The term “dovetail” comes from the idea that the joints fit together like jigsaw pieces.
dried-in When the exterior envelope (siding, roofing, windows, and doors) are installed in a house.
drop axle trailer A trailer that allows for about 4 inches of added head room in a Tiny House On Wheels (THOWs).
emergency egress Doors, windows, and emergency access loft windows that provide escape routes for building inhabitants.
energy recovery ventilator (ERV) A mechanical system that provides conditioned fresh air to a home by means of exchange.
expanded polystyrene (EPS) A rigid foam insulation product.
extruded polystyrene (XPS) A rigid foam insulation product.
fifth-wheel trailer A system in which the trailer connects to a pickup truck with a hinged plate.
floor plan An architectural representation of a structure or room from a bird’s eye point-of-view.
foundation plans Details on a set of architectural plans that highlight how to construct the foundation.
full-timer’s RV insurance A policy extended by certain insurance companies to people living full-time in their RVs.
gable roof A roof design in which both roof sides angle up to a gable peak.
gooseneck trailer A system in which the trailer slides over a ball hitch in a pickup truck bed.
Gross Trailer Weight (GTWR) The total weight of a trailer when loaded to capacity, including the trailer itself and any loads.
Gross Vehicle Weight Rating (GVWR) The total weight of a vehicle when loaded to capacity, including the vehicle itself and any loads plus people.
ground fault circuit interrupter (GFCI) plugs Plugs designed to shut off an electric circuit when a current is flowing along an undesired path (such as through water or a person).
header A horizontal framing member placed above a door, window, or other opening.
heat recover ventilator (HRV) A mechanical system that provides conditioned fresh air to a home by means of exchange.
Home Owner’s Association (HOA) An association that governs a planned development, such as a condo, townhouse, or neighborhood, to which homeowners pay maintenance dues.
homeowner’s insurance policy A standard policy that protects a house, its contents, and the property the home sits on; liability coverage is included, too.
Housing and Urban Development (HUD) A federal organization tasked with developing affordable housing in the United States. It regulates construction standards of manufactured housing as well as other tasks.
HTT4 Heavy duty metal brackets used when connecting wall framing systems to a trailer frame.
hurricane clips Metal clips used to anchor roofing systems to the wall systems in order to withstand high-wind events.
HVAC system Heating, ventilation, and air condition systems involved in climate control.
inland marine insurance policy Insurance for property in transit over land.
in-line vents An integral part of the plumbing system designed to enable P-traps to retain water.
insurance endorsement A document attached to an insurance policy that amends the policy in some way.
insurance rider An insurance add-on that provides additional coverage benefits.
International Code Council (ICC) An organization that develops construction standards and codes for the construction industries.
International Residential Code (IRC) Construction code used for one- and two-family dwelling unit construction in the United States and its territories.
item priority circle drawing An architectural drawing technique that creates bubble representations of various rooms in a floor plan.
jack stand A vertical support member designed to carry trailer loads.
king stud A vertical framing member placed on either side of a door or window, running from bottom plate to top plate.
live load Any consistent load exerted on a structure.
load on a trailer Any item carried on a trailer. A permit can sometimes be issued by the DOT in which a tiny house is considered a load on a trailer.
load path The path through which loads pass from the highest point in a structure through the wall systems, floor, foundation, and eventually to the ground.
maximum vehicle height The tallest that a trailer may be in order to be road legal without the use of special permits. In most states, it’s 13'6", while in some it’s 14'6".
maximum width limit The widest that a trailer may be in order to be road legal without the use of special permits. In most states, it’s 8'6".
metal strapping Continuous banding made of differing gauges of galvanized steel used to secure structures to the ground.
mini-split A small-space conditioning system that sometimes includes both heating and cooling in the same device.
miter joint A joint in which two opposing angles are cut to equal the total angle of the joint.
moisture barrier Membrane installed on exterior face of a wall to eliminate movement of moisture into a house.
municipality Any city or town with corporate status and a local governing body.
National Electric Code (NEC) Standards used for code enforcement of electrical installations in the United States.
open-cell spray foam A spray foam insulation product that is less dense than closed-cell foam.
Pacific West Associates, Inc. (PWA) A fee-based, third-party inspection program designed for tiny houses.
perimeter concrete foundation A continuous concrete wall atop concrete footers designed to support structural loads above it.
permanent foundation A foundation permanently attached to the ground.
permanent wood foundation A continuous foundation wall built from pressure treated wood in combination with drainage rock.
PEX A flexible plastic material often used in plumbing applications.
pigtail A small length of wire attached to the main electrical wires inside an electrical box.
pintle hitch A hook and loop trailer hitch designed to carry heavy loads.
plat A scaled map showing divisions of a piece of land.
polyiso (ISO) A rigid foam insulation product.
PVC A plastic composite material used in plumbing applications.
rafter A framing member that supports the roof sheathing.
rainscreen A construction system designed to provide ventilation behind siding in order to improve durability and eliminate excess moisture in a wall system.
Recreational Vehicle Industry Association (RVIA) An organization tasked with promoting the RV industry. It’s also in charge of adopting and enforcing construction safety standards.
renter’s insurance policy An insurance policy providing coverage for the contents in a rental property; the structure itself, however, is not covered.
replacement cost coverage (RCC) An insurance option that replaces contents at current market value without taking depreciation into consideration.
ridge beam A horizontal framing member that supports the end rafter at the ridge.
riser The vertical portion of each step on a set of stairs.
Romex The most common type of electrical wiring on the residential construction market.
roof dormer A vertical opening in a gabled roof line that increases the amount of usable space in a loft.
room-relationship bubble sketch A series of simple hand-drawn circles that represent the rooms in a house.
rough opening (R.O.) The space left open in framed wall assembly to accommodate the future placement of a door or window.
rough sill A horizontal framing member placed below a rough window opening; it is attached to the cripple stud below the R.O., and the trimmer and king studs on the side.
rule of thirds A composition concept used in photography to visually add interest to the subject.
R-value The insulation potential of a material.
RVIA certification The seal of approval given to a participating builder that has met RVIA standards.
RVIA manufacturer A construction company that has passed the RVIA certification process.
scale When proportions between all objects and lines remain the same no matter how large or small a structure is represented.
section A perspective view on a detail on a set of architectural plans.
septic tank An underground tank where sewage is collected and permitted to decompose before being carried to a leach field.
shear strength A structure’s ability to resist forces imposed in-line with the plane of the wall.
shed roof A single sloped roof. In tiny house construction, it’s often the roof style that allows for the greatest usable head room in a loft.
ships ladder A hybrid between stairs and a ladder.
sill plate A horizontal framing member fastened directly to top of foundation (or trailer).
stair riser The vertical portion of each step on a set of stairs. It’s the part of each step that actually rises the stairs from one tread to the next.
stair tread The horizontal step on a set of stairs. This is the weight-bearing portion of the stairs.
Structural Insulated Panels (SIPs) A custom factory-built structural system with embedded high-insulation foam.
structural screws Specialty screws rated to withstand shear forces.
sway bars An aftermarket add-on that helps spread loads from the trailer to the tow vehicle’s rear axle.
thermal bridging The process in which heat moves to colder areas.
tiny house A dwelling that’s 400 square feet or less, excluding lofts.
tiny house movement A collective of people interested in the tiny house lifestyle.
Tiny House On Foundations (THOFs) A tiny house built on a permanent foundation.
Tiny House On Skids (THOSs) A tiny house built on a skid system that can be hauled on a trailer or attached to a permanent foundation.
Tiny House On Wheels (THOWs) A mobile tiny house built on a trailer with wheels.
tiny house shell A pre-built tiny house typically completed to the point of being dried-in.
title page The first page on a set of architectural plans that contains important details about the plans.
tongue weight Downward force exerted from the trailer tongue to the tow vehicle’s hitch.
top plate A horizontal framing member fastened to top of wall studs.
trailer brakes Brakes installed on the trailer and connected electronically to the tow vehicle.
tread The horizontal step on a set of stairs.
trimmer stud A vertical framing member placed on the inside of a king stud.
vapor barrier A protective membrane installed into a structure to seal out moisture.
variance An official request to deviate from the standards of current zoning requirements.
ventilation Mechanical systems that exhaust stale air and/or provide fresh air to a home.
virtual private network (VPN) A security measure added to a web network that encrypts personal information and data.
wall stud A vertical framing member in a wall system.
wide load permit A special permit issued to an applicant allowing for the legal transport of a trailer that exceeds normal width limits.
window schedule On architectural plans, it describes the window information for a structure.
zoning department This organization is charged with regulating the use of land in a municipality, including where a THOWs may be parked.