Construction · Lesson 1 of 13Beginner8 min read

The Big Picture

A house is built from the ground up, in an order that lets each crew work on what the last one finished. This lesson walks through that order, meets the people who do each part, and explains the rules that keep the result safe. The map shows every system in one house.

How a house goes up

Every wood-frame house follows roughly the same path from bare ground to move-in day.

Site work. The lot is cleared, the hole for the foundation is dug, and the ground is shaped so rain will drain away from the house later. Lesson 3
Foundation. Concrete footings spread the house’s weight over the soil. Walls or a slab go on top. Lesson 3
Framing. Carpenters build the floors, walls and roof frame, the skeleton of the house. Lesson 4
Roof, windows and doors. Once the roof is covered and the windows and outside doors are in, the house is “dried in”: rain stays out, and the inside work can begin. Lesson 5
Rough-ins. Plumbers, electricians and HVAC technicians run pipes, wires and ducts through the open walls, floors and ceilings.
Insulation and air sealing. The walls and attic are insulated, and gaps are sealed. Lesson 6
Drywall. Sheets of gypsum board cover the framing, and the joints are taped and smoothed. Lesson 7
Finishes. Trim, doors, floors, paint, cabinets, light fixtures and faucets go in last.

The order varies by builder and by place, and so do the inspections: the local building department decides which ones a permit needs. Sources: U.S. Bureau of Labor Statistics (what inspectors check and when); DOE Building Science Education Solution Center.

WhyWhy the order matters

Each step hides the one before it. Once the drywall goes up, nobody can see the pipes, wires, framing or insulation inside the walls. That’s why building inspectors check the work at several stages, while it’s still in view, instead of only at the end.

A map of the house

Here is one house, cut open from front to back so you can see inside: a basement foundation, a wood frame, a truss roof and everything in between. Point at a part (or tap its name below) to see what it does, and click to open its lesson. Switch between Structure and Finished to peel the layers away.

The skeleton: foundation, framing, roof trusses, and the pipes, wires and ducts inside the open walls. Point at a part.

Drawn as a one-story house over a basement so every part shows. Many houses sit on a slab or a crawlspace instead; Lesson 3 compares all three.

The systems at a glance
Part	What it does	Signs of trouble
Site and drainage	Shapes the ground so water flows away from the house.	Puddles against the foundation, a wet basement, erosion.
Foundation	Spreads the house’s weight over the soil and keeps the wood up out of the ground.	Cracks that grow, water coming in, walls that bow or lean.
Floor and wall framing	The skeleton: joists, studs, plates and headers carry the loads down.	Bouncy or sagging floors, doors that suddenly stick.
Roof	Trusses or rafters carry snow and wind; layers of roofing shed water.	Leaks, ceiling stains, ice dams, missing shingles.
Envelope	Siding, house wrap, flashing, insulation and air sealing keep out water, air and heat.	Drafts, high energy bills, rot, condensation.
Windows and doors	Let in light and people, and keep out weather.	Drafts, fogging between panes, water stains under sills.
Rough-ins	Pipes, wires and ducts run inside the framing.	Leaks, tripping breakers, rooms that won’t heat or cool.
Interior finishes	Drywall, trim, floors, paint and stairs: what you see and touch.	Nail pops, cracks, peeling paint, loose stair parts.

The rough-ins: where the other trades come in

“Rough-in” is the stage when pipes, wires and ducts are run through the open framing, before insulation and drywall cover them. Three other trades do this work, and each has its own course in The Trades:

Plumbing: water supply lines, and the drain and vent pipes that carry wastewater away. The Trades: Plumbing
Electrical: the service panel, cables, and the boxes for outlets, switches and lights. The Trades: Electrical
HVAC: the furnace, air conditioner or heat pump, and the ducts that carry air to each room. The Trades: HVAC

Inspectors check plumbing, electrical and other systems to make sure they meet the code. Rough-in work usually gets inspected while the walls are still open.

Who does what

A house takes many trades. The U.S. Bureau of Labor Statistics describes each one in its Occupational Outlook Handbook:

Some of the people who build a house
Who	What they do
Construction laborers and helpers	Prepare and clean the site, load and unload materials, build and take down bracing and scaffolding, dig trenches, and assist the other trades.
Carpenters	Follow blueprints; build frameworks, including walls, floors and doorframes; install windows and molding; and repair damaged framing.
Roofers	Install shingles, metal or other materials to make the roof weatherproof. Steep-slope roofs are typical on single-family homes.
Plumbers, electricians, HVAC technicians	Install the rough-ins and, later, the fixtures, devices and equipment.
Drywall installers and tapers	Measure, cut and fasten drywall panels, then tape, coat and sand the joints smooth.
Construction managers	Plan, coordinate, budget and supervise the project from start to finish.
Construction and building inspectors	Check that the work meets building codes, zoning rules and contract specifications.

Building codes, permits and inspections

A building code is a set of minimum rules for building safely: how strong the structure must be, how the house resists fire, how stairs are built, how much insulation it needs, and much more. Many states and cities base their rules on model codes, such as the International Residential Code for houses and the International Energy Conservation Code for energy use, and they may change them. The building department where you live decides which rules apply there. Builders call it the authority having jurisdiction.

Before most building work starts, the builder or owner applies for a permit. A plans examiner checks the drawings against the adopted codes. Then building inspectors visit the job several times: an early check, follow-up inspections as the work goes on, and a full examination when it’s done. Inspectors can issue violation notices and stop-work orders if the work doesn’t comply.

A home inspector is different. A buyer usually hires one to report on a house’s structure and condition, but home inspectors have no authority to enforce the building code.

NoteThe local code is the final word

This course explains how houses are built in general. The code your city or county has adopted, and the building department that enforces it, decide what’s required where you live, including which jobs need a permit and inspections. Structural changes need a permit and often an engineer, and some work legally needs a licensed contractor.

Check yourself

Tap an answer to check it, or open “Show the answer.”

Which happens first?
Show the answer
Rough-in plumbing and wiring. Pipes, wires and ducts are run through the open framing first. Drywall would hide them.
Who checks building plans against the codes a city has adopted?
Show the answer
A plans examiner. Plans examiners review the drawings; building inspectors then check the work on site.
What can a home inspector hired by a buyer do?
Show the answer
Report on the house’s structure and condition. Home inspectors report on condition. They have no authority to enforce building codes.
Which system includes the siding, house wrap, flashing and insulation?
Show the answer
The envelope. The envelope separates inside from outside and controls water, air, vapor and heat (Lesson 6).

Go deeper

Lesson 2: Loads and Structure Next: how the weight of a house finds its way to the ground.
The Trades: Plumbing Supply and drain lines, traps, vents and fixtures.
The Trades: Electrical Service panels, circuits, grounding and safe testing.
The Trades: HVAC Furnaces, air conditioners, heat pumps and ducts.
U.S. Bureau of Labor Statistics, Occupational Outlook Handbook: Construction and Building Inspectors What building inspectors check, and how to become one.

Sources

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A free course from Teddy Rook Book. It explains how houses are built in general and follows U.S. sources; the local building code, the building department and the manufacturer’s instructions are the final word.