Understand the sequence of construction

A building goes together in an order that is mostly forced: you cannot hang drywall over wiring an inspector has not seen, you cannot template a countertop on cabinets that are not set, and you cannot finish drying in a shell while the windows are still at the factory. This module teaches the order, the handoffs between trades, the points where an inspector or a delivery holds everything, and why no two projects follow the same calendar. The output is a dependency map for your own project, not a schedule; the schedule comes later, from written lead times and your department's answers.

1. Dependencies, handoffs and holds Understand

Three words do most of the work in this module.

• A dependency is a task that cannot start until another is finished. Drywall depends on insulation, which depends on passed rough-in inspections, which depend on the rough-in work, which depends on the framing, which depends on the foundation. Some dependencies are physical (the wall must exist before it can be wired), some are regulatory (the wall must be inspected before it can be covered), and some are commercial (the cabinets must be on site before the installer comes). All three kinds are real.
• A handoff is the moment one trade's finished work becomes another trade's starting condition. The framer hands a dried-in shell to the plumber, electrician and HVAC installer; the cabinet installer hands set and leveled boxes to the countertop fabricator for templating. Every handoff has a condition attached ("level, anchored, sink on site") and most problems between trades are a handoff whose condition nobody wrote down.
• A hold is a point where the work stops until someone outside the crew acts: an inspector passes the rough-in, a delivery arrives, a plan reviewer approves a revision, a lender releases a draw. Holds are where schedules slip, because the person who releases them is not on your payroll and has their own queue.

The practical skill this module builds is to see your project as a chain of dependencies with holds marked on it, so that when someone proposes a date you can ask "what has to be true by then, and who makes it true." That question, asked early, is most of what a good construction manager does.

2. The inspection spine and rough-in versus finish

Most residential building departments inspect at roughly the same hold points, though the names, groupings and extras differ from city to city and some states send their own electrical inspector. The common spine, from several municipal inspection guides, looks like this. Treat it as vocabulary, then get your own list from the permit.

Three practical rules recur in municipal guides and are worth adopting whoever is managing your project: work stays uncovered until it is approved; inspection requests usually need a day or two of notice; and the permit number must be ready when you call. "Ask before you pour or cover" is a habit, not a rule, and it is one of the cheapest habits in construction.

Rough-in and finish, trade by trade

Each mechanical trade typically visits at least twice: once with the walls open, once at the end. The two visits are weeks or months apart and depend on different things.

3. Lead times: what others were seeing, and why you get your own in writing

A lead time is the gap between ordering something and having it on site. Long-lead items are the second kind of hold in your sequence, and they are different from inspection holds in one way: you can move them by ordering earlier, but only if the order is based on verified dimensions and a design that will not change. Ordering early against plan dimensions and then having plan check change a window size is a well-known way to pay for a window twice.

There is no authoritative national dataset of residential lead times. The ranges below come from trade press and vendor pages, most from 2025 and 2026, and they are here so you know which items to ask about, not so you can schedule from them. The instruction that goes with the table is simple: for every item on it that your project uses, get a written lead time from the supplier you will actually use, dated, and build the schedule from that.

For perspective on how much these move, one industry analysis from October 2021 reported that at that peak window lead times averaged 4 to 15 weeks with some at 20 to 45 weeks, against 2 to 3 weeks before the pandemic. A lead time is a snapshot of a market, which is why the course keeps saying "dated, in writing, from your supplier."

Permit review is a lead time too

Module 4 showed published review targets from several departments ranging from about five to twenty working days for a first review, with warnings that the full process for a new house can take far longer, and that corrections restart the clock. Treat review the way you treat windows: a hold with a range, narrowed only by asking your department what projects like yours actually take, and by submitting a complete application.

4. Why there is no universal schedule

People ask "how long does a kitchen take" and "how long does a house take" and are frustrated by the honest answer. Here is why the answer is honest.

• Jurisdiction. Which inspections exist, their order, who performs them, how far ahead they must be requested, and how long review takes are all local. Two identical additions in neighboring towns can differ by weeks on holds alone.
• Existing conditions. A 1958 house has surprises a 2015 house does not: undocumented wiring, rot under a sink, a foundation that was not built the way the drawings assume. Each surprise is a stop, a decision, sometimes an engineer, and a change order.
• Weather and region. Concrete, roofing and exterior work are weather-dependent; a winter start in a cold climate and a summer start in a monsoon region each have a season to work around. NAHB's analysis of Census data shows the regional spread plainly: in 2025 the average single-family build ran 13.5 months in New England and 7.6 months in the South Atlantic.
• Who is managing. The same Census data separates homes by who built them. In 2025, homes built for sale by a builder averaged 7.4 months of construction; contractor-built homes (the owner hired a general contractor on the owner's lot) averaged 11.7 months; owner-built homes averaged 14.3 months; built-for-rent homes averaged 12.4. The prior year's figures were similar: 9.1 months overall and 15.1 months for owner-built. The overall 2025 average was 8.8 months from permit authorization to completion, made of 1.4 months from authorization to start and 7.4 months of construction.
• Decisions. Late owner selections, revisions after approval and change orders each add days that a sequence rarely absorbs, because they tend to land on the critical path: the trade is waiting for the decision.
• Trade availability. A trade booked for three weeks is a three-week hold, and contractor-side sources and owner-builder forums both report that trades tend to prioritize repeat contractor clients over one-off homeowner jobs. The course has no survey data on it; treat it as a constraint to plan for rather than a certainty or a myth.

Those Census averages are averages, not predictions. They include every size of house, every region and every kind of builder, and the owner-built figure does not tell you why owner-built homes take longer (part-time management, financing in stages, doing some work yourself, waiting for trades) or whether yours would. What they do say is that the gap between "a builder's production house" and "an owner managing their own" is measured in months, not weeks, and that your schedule should start from your own holds, not from a national number.

Source: the NAHB Eye on Housing post on 2025 construction time reports the Survey of Construction averages by builder type and region; the post on 2024 construction time gives the prior year's figures.

5. See it: four walkthroughs and a dependency diagram See it

Four illustrative project types, each walked through in order, with its hold points, where third-party tests fall, where weather risk concentrates, and what the owner must have decided before each phase. These are syntheses of contractor guides and municipal handouts; they are typical, and yours will differ in the particulars.

(a) Kitchen remodel in an occupied house

1. Design final; appliances chosen and dimensions confirmed from the actual units; cabinets ordered; permits applied for. Owner decides: layout, appliance models, sink, lighting plan, whether flooring runs under cabinets. Hold: cabinet lead time (reported at two to twenty weeks depending on tier, section 3) and permit review. A common rule of practice: nothing is demolished until the cabinet delivery date is known.
2. Containment and a temporary kitchen. Plastic walls, floor protection, a path to a bathroom that does not cross the work zone, the HVAC adjusted so dust does not travel. Owner decides: where the family eats for the duration, whatever the map says it is.
3. Demolition. Photograph existing plumbing and wiring before disconnecting. In a pre-1978 house, lead-safe practice and any asbestos testing happen before this step, not during (Module 4).
4. Framing changes, then plumbing, electrical and gas rough-in to the final cabinet layout. This is where the layout stops being adjustable. Owner must have decided: everything in step 1, plus outlet and switch positions.
5. Rough-in inspections. hold Everything downstream moves if this slips. In many departments the framing inspection follows the rough-ins.
6. Insulation where an exterior wall was opened (and its inspection), drywall, prime.
7. Flooring, either before the cabinets (tile, commonly) or after, around them. Decided in step 1 because it changes cabinet height.
8. Cabinets set, leveled, anchored. Handoff condition for the fabricator.
9. Countertop template with sink and cooktop on site; fabrication (typically one to three weeks, ask the fabricator); install. lead The kitchen has no sink during this gap. Plan for it.
10. Appliances, backsplash, finish plumbing, finish electrical, trim, hardware, paint touch-up.
11. Finals close the permits. hold

Third-party tests: usually none, unless lead or asbestos testing before demolition. Weather risk: low, unless an exterior wall or window is involved. Most of the owner's hardest decisions come before step 4.

(b) Single-story addition

1. Assessment and engineering. Existing foundation, roof framing, electrical and plumbing capacity; survey and setbacks; an engineer's detail for the tie-in between new and old foundations and roofs. Owner decides: size and position (constrained by the Module 4 answers), and the level of finish, because it drives the budget before bids.
2. Permit review. hold Long-lead orders that plan check could change (windows, trusses) wait for approval; orders it cannot change can be quoted and held ready.
3. Survey and stake, excavation, footings. Footing inspection before concrete. hold Where footings bear on fill, a compaction test by a soils technician may be a condition of the soils report, done just before the pour.
4. Foundation, including the connection to the existing foundation (commonly dowels set into the old wall per the engineer's detail). Foundation inspection, then backfill. hold New and old foundations that settle differently are a failure mode contractor guides warn about; this detail is not the place for a field improvisation. Order trusses now if the design uses them. lead
5. Framing walls and roof; roof tie-in to the existing structure. A temporary wall keeps the house closed off until late in the job. Some departments inspect shear and nailing here.
6. Dry-in: sheathing, water-resistive barrier, flashing, windows and doors. lead If the windows are late, you cannot complete the dry-in; a temporary enclosure is a task with a cost and an owner, not a workaround (see the scenario). Some departments inspect the barrier and flashing before siding.
7. Rough-ins in the new space and extension of existing systems. Panel capacity and HVAC capacity are the common change-order sources here. Rough-in inspections, then framing inspection. hold
8. Insulation and inspection; drywall. An energy test (blower door, duct leakage) may be required by a third party before or at final; ask at permit issuance. hold
9. Open the wall between old and new as late as possible; align floor heights; finish the roof junction flashing. Owner decides: how the household lives through the days the wall is open.
10. Finishes, exterior cladding, finals. hold

Weather risk concentrates between removing the existing roof or siding at the tie-in and dry-in. Experienced builders plan a tarping strategy and a weather window for that span; the course's advice is not to start it until the window delivery date is confirmed in writing. The diagram below shows the chain.

(c) Detached accessory dwelling unit (ADU) or garage

1. Feasibility with the zoning office and the utilities. Setbacks and coverage for accessory structures; whether a soils report is required for any new structure (one California city's ADU guide says it may be); whether a separate electric meter and panel are required (one Wisconsin city's guide requires them); whether sewer connection is required when a main is within a stated distance (one California county sets such a distance); utility fees and lead times. Owner decides: size, whether the unit is conditioned and plumbed (a garage without plumbing skips most of the utility work), and whether to use a pre-approved plan where the jurisdiction offers one (one county cites a review of up to 30 days for pre-approved plans).
2. Permit review. hold
3. Site preparation, then utility trenching (water, sewer, electric, possibly gas) with an underground inspection before backfill. hold The utility's own crews set the meter on the utility's schedule. lead
4. Footing and foundation, with inspections. hold For a slab garage: footing, then slab, with under-slab plumbing inspected if any.
5. Framing, dry-in (windows on site), rough-ins, rough and framing inspections. hold A garage that is not conditioned typically has only an electrical rough-in.
6. Insulation and inspection, drywall, finishes. An energy test by a third party may apply to a conditioned unit. hold
7. Finals and, for a dwelling unit, a certificate of occupancy. One county's process has the builder schedule the final through the department's portal, with the certificate issued after it passes. hold

Weather risk: the same roof-to-dry-in window as an addition, plus open trenches in wet weather. Third-party tests: compaction where the soils report requires it, an energy test for a conditioned unit, a potable-water test if on a well. One city's guide estimates six to twelve months of construction for an ADU; treat that as one city's experience, not a plan. The distinguishing hold on this project type is the utility, and the course's instruction is the same as the city guides': contact the utilities early, in writing.

(d) New single-family home

1. Site work before the spine: clearing, grading, erosion control, temporary power, driveway or access, and either well and septic or municipal connections. The health department's septic sequence and any well requirement can precede the building permit (Module 4). hold Owner decides: the complete design and most selections, because a fixed-price contract and a construction loan both want them.
2. The generic spine: footing (often with a survey certification), foundation and under-slab, under-floor if there is a crawlspace, framing with trusses ordered weeks ahead, shear or nailing where inspected, dry-in with windows on site, rough-ins, framing inspection, insulation and energy, drywall where inspected, finals. Each hold as in section 2. hold
3. Third-party reports along the way: compaction testing before footings where required; engineer's observation letters confirming the bearing or the framing hardware where the department asks for them; the blower-door and duct tests for the energy code; the well water test from a certified lab before occupancy; the septic as-built and certificate of compliance; an as-built survey at closeout.
4. Lender draws on their own schedule, after a draw inspection, for work in place. lead A late draw can delay paying a trade, which delays the trade.
5. Exterior finishes, interior finishes, landscaping and driveway, final steps, certificate of occupancy. hold

Weather risk: site work and foundations in wet or frozen ground; the roof-to-dry-in window; exterior finishes at the end. The Census averages in section 4 describe this project type, and they say the same thing the walkthrough does: a new house is a long chain of holds, and who is managing the chain is one of the variables the averages are split by, with a gap of months between them and no explanation of why.

6. Practice: build your dependency map Practice

Time: about 60 to 90 minutes. Open the dependency map and look-ahead schedule. It has two parts: a dependency map (tasks with what each depends on, who releases it, and what kind of hold it is) and timing assumptions (weeks of design, weeks of review, bid period, longest lead time, construction duration, weather buffer) that derive a rough window from your own figures. Then:

1. Pick the walkthrough closest to your project type and copy its phases into the map as rows, in order. Delete what does not apply and add what the course could not know: the retaining wall, the second bathroom, the barn you are also repairing.
2. For each row, write what it depends on (the previous phase, an inspection, a delivery, an owner decision, a draw) and who releases the hold (the building department, the supplier, you, the lender). A row with no dependency is either the first row or a mistake.
3. Mark the holds by type: inspection, delivery, review, decision, money. Count them. That number is the number of things outside your crew's control that have to happen on time.
4. List the long-lead items your project uses, from the table in section 3, and next to each write "written lead time: not yet" until you have one. These are the assumptions that most need replacing with facts.
5. Write the owner decisions due before each hold, especially before rough-in. If you cannot name the decision, you have found a place the schedule will slip.
6. Fill in the timing assumptions with your best current guesses, labelled as guesses, and look at the window the tool derives. Then compare it with your preferred start and finish from setup. The gap is the agenda for your next conversations.

Then compare your map with the criteria in Check your work.

7. Your project Your project

8. Check your work Check your work

Criteria

• Every row names what it depends on and who releases it; no row is "then the next thing happens."
• Every inspection hold is on the map in the position your department (not the course) puts it, or is marked "order to be confirmed with the department."
• Every long-lead item has a row of its own for the order, placed early enough that its lead time lands before the task that needs it, and is marked with whether the lead time is a written quote or a guess.
• The owner decisions due before rough-in are listed by name with a due date.
• Weather-exposed spans are marked, and there is a buffer or a tarping plan next to them.
• The derived window in the timing tool is labelled as made of your assumptions, and you can say which assumption you are least sure of.

Worked example: three rows from the Birch Lane addition map

Common mistakes

• Putting dates on the map before the holds are known. The map is dependencies first, durations second, dates last. Dates written early become promises nobody can keep.
• Treating the course's inspection order as yours. Framing-before-rough-ins and rough-ins-before-framing both exist. Ask.
• Forgetting that third-party tests have their own lead time and a retest loop. A blower-door test that fails is a week of air sealing and a second appointment.
• Leaving owner decisions off the map. They are holds, and you are the one who releases them.
• Scheduling dry-in before the window ship date is confirmed. This is a common way an addition ends up sitting under a tarp.
• Treating a national average as a duration. The Census figures describe a population; your map describes your holds.

What is still unresolved after this exercise

• Your department's actual inspection list and order (from the permit, Module 4).
• Written lead times from the suppliers you will actually use (Module 8).
• Whether the trades you want are available in the window the map implies (Module 7).
• How the lender's draw schedule, if any, lines up with the trades' payment expectations (Module 6).
• What the budget looks like once the map shows how many holds and how much weather you are carrying (Module 6).

9. Knowledge check and scenario

Before you move on

• My dependency map has a "depends on" and a "who releases it" entry for every row.
• I have asked (or written the question to ask) my building department for the complete inspection list and order for my permit.
• Every long-lead item on my map is marked "written lead time" or "guess," and the guesses have a supplier's name next to them.
• I have listed the owner decisions due before rough-in, by name.
• The timing assumptions in my binder are filled in and labelled as my assumptions, and I know which one I am least sure of.