Building Procurement Cost Sequencing Materials And Quality

---
name: building-procurement-cost-sequencing-materials-and-quality
description: "Use for delivery and construction: procurement and delivery models and how each allocates risk, cost estimating and why estimates move, sequencing and temporary works including the falsework and propping that cause a disproportionate share of collapses, materials in construction, and quality and inspection regimes."
---

# Buildings and Civil Structures: Procurement and Delivery, Cost, Sequencing and Temporary Works, Materials in Construction, and Quality and Inspection

> **Part 4 of 6** of the *Designing and Building Buildings and Other Civil Structures* reference (plugin `designing-and-building-buildings`), covering §15–§19. Sibling skills: `building-disciplines-site-brief-planning-and-design` (§0–§5), `building-structure-foundations-envelope-services-and-fire` (§6–§10), `building-accessibility-energy-drawings-bim-and-codes` (§11–§14), `building-site-safety-commissioning-retrofit-and-why-projects-fail` (§20–§23), `building-reference` (§24–§29). Section numbers are shared across the set; a reference written as §N → `skill` points into that sibling skill.
>
> **Currency:** The engineering is settled. Two areas moved. See §24 → `building-reference` for tall mass timber code adoption, and embodied carbon regulation.

> **⚠️ The practice companion to a civil/industrial engineering reference.** ⚠️ **That one
> translates concepts for outsiders — factor of safety, codes as accumulated failure logs,
> the megaproject estimation record.** **This one is how the work is actually done.**
>
> **⚠️ The organizing reality: a building is a MULTI-DISCIPLINARY SYSTEM delivered by
> parties with different contracts, different liabilities and different incentives.**
> ⚠️ **Most building failures are not engineering failures — they are COORDINATION
> failures at the boundaries between disciplines and between design and construction**
> (§23 → `building-site-safety-commissioning-retrofit-and-why-projects-fail`).
>
> **⚠️ GOTCHA** boxes mark the assumptions that cause litigation.
>
> **⚠️ Scope note**: ⚠️ **structural, fire and geotechnical design are licensed activities
> in most jurisdictions for good reason. This is a map of the territory, not a
> substitute for a qualified engineer or a local code review.**
>
> **The three ideas that organize this document:**
> 1. **⚠️ Design decisions bind cost early and irreversibly** (§1 → `building-disciplines-site-brief-planning-and-design`, §16). **Most of a
>    building's cost and carbon are committed during concept design, when almost nothing
>    has been spent.**
> 2. **⚠️ WATER destroys more buildings than structural failure** (§8 → `building-structure-foundations-envelope-services-and-fire`). **Envelope and
>    moisture management cause the overwhelming majority of building defects, claims and
>    premature failures — and they are the least glamorous part of the job.**
> 3. **⚠️ Load paths and lateral systems are the two things a structure is** (§6 → `building-structure-foundations-envelope-services-and-fire`).
>    **Gravity is the obvious problem; wind and seismic are the ones that govern.**

---

## §15. Procurement and Delivery

```
⚠️ DESIGN-BID-BUILD  ⚠️ sequential; owner holds design risk;
   lowest-price tender; ⚠️ adversarial change-order dynamics
⚠️ DESIGN-BUILD  ⚠️ single point of responsibility; faster; ⚠️ owner
   has less control over detail and must specify performance well
CONSTRUCTION MANAGEMENT  at-risk (GMP) or agency
⚠️ IPD / ALLIANCING  ⚠️ shared risk and reward, multi-party contract.
   Best evidence for complex projects, and requires unusual maturity
   from all parties
```
**⚠️ Contract forms** (**AIA, FIDIC, JCT, NEC**) — ⚠️ **and NEC in particular is designed
around EARLY WARNING and collaborative change management rather than retrospective claims,
which is a meaningful difference.**
**⚠️ Risk allocation is the substance**: ⚠️ **the party best able to CONTROL a risk should
carry it, and allocating risk to a party who cannot control or price it produces claims,
insolvency, or a price loaded with contingency.**
**⚠️ Retention, liquidated damages, bonds and insurance** — ⚠️ **and professional indemnity
insurance shapes designer behaviour more than most people realize.**

---

## §16. Cost

**⚠️ Estimate types by stage**: ⚠️ **order-of-magnitude (per m² or per unit) → elemental →
detailed quantity-based.** **⚠️ The accuracy range narrows as design develops, and quoting
a concept estimate as if it were a tender price is a classic and damaging error.**
**⚠️ Contingency** should be stated and staged; ⚠️ **and note that "contingency" for design
development is a different thing from "contingency" for construction risk.**
**⚠️ Whole-life cost** — ⚠️ **capital cost is typically a fraction of lifetime operating and
maintenance cost, so optimizing capital alone is frequently the wrong objective.**
**⚠️ The estimation record**: see a civil/industrial engineering reference for the
megaproject overrun data and ⚠️ **reference class forecasting, which is the evidenced
remedy — anchor to what similar completed projects actually cost, not to a bottom-up
build-up.**

---

# PART IV — CONSTRUCTION

## §17. ⚠️ Sequencing and Temporary Works

**⚠️ Critical path method** (see a civil/industrial reference) — ⚠️ **and the practical
addition here is that NEAR-critical paths become critical the moment anything slips, so
monitoring only THE critical path misses most schedule risk.**
> **⚠️ GOTCHA — TEMPORARY WORKS are engineered structures in their own right, and a
> notable share of construction failures happen DURING construction rather than after.**
> ⚠️ **Formwork and falsework, shoring, scaffolding, excavation support, crane bases,
> propping during demolition and alteration — all carry real loads, often on a structure
> that is not yet capable of carrying itself.**
> **⚠️ A partially built structure has NO lateral system until the diaphragms and bracing
> are in (§6 → `building-structure-foundations-envelope-services-and-fire`), which is why temporary bracing is not optional and why steel frames are
> braced during erection.**
> **⚠️ Formwork failures during concrete pours are a recurring and severe accident
> category — wet concrete is a fluid exerting hydrostatic pressure, and pour rate is a
> design input.**

**⚠️ Sequencing realities**: ⚠️ **enclosure before wet trades; services rough-in before
closing ceilings; curing time is not compressible; weather; and ⚠️ the trade stacking
problem where too many crews in one area destroy everyone's productivity.**
**⚠️ Lean construction and the Last Planner System** are the credible responses —
⚠️ **short-interval planning by the people doing the work, with constraint removal ahead
of time** (see a civil/industrial reference on flow).

---

## §18. Materials in Construction

**⚠️ CONCRETE**: ⚠️ **mix design (w/c ratio governs strength and durability — more water
means weaker and more permeable), placement, consolidation, and ⚠️ CURING, which is the
step most often shortchanged and which determines durability far more than mix strength.**
**⚠️ Cover to reinforcement is the single most important durability parameter**, ⚠️ **because
inadequate cover lets chlorides and carbonation reach the steel, which then rusts and
spalls the concrete off.** **⚠️ Cold and hot weather concreting have specific procedures.**
**⚠️ STEEL**: **fabrication off site, erection tolerances, ⚠️ bolted versus welded
connections (⚠️ site welding is slower, weather-dependent and harder to inspect), fire
protection, and corrosion protection.**
**⚠️ MASONRY**: ⚠️ **compression only; movement joints are mandatory (brick expands over
time, concrete block shrinks — in opposite directions); mortar should be WEAKER than the
units so cracks occur in the joint where they can be repointed.**
**⚠️ TIMBER and MASS TIMBER**: **moisture content, connection design, and ⚠️ protection
from wetting during construction, which is a genuine mass timber programme risk** (§24.1 → `building-reference`).

---

## §19. Quality and Inspection

**⚠️ Quality is built, not inspected in** — ⚠️ **but verification exists because that
statement is aspirational.**
**⚠️ Mechanisms**: **submittals and shop drawing review, ⚠️ MOCK-UPS (⚠️ the single most
effective quality tool for façades and finishes — build it, test it, agree it, then it's
the benchmark), witness and hold points, special inspections (§14 → `building-accessibility-energy-drawings-bim-and-codes`), and
⚠️ NON-DESTRUCTIVE TESTING (concrete cube/cylinder tests, rebar scanning, weld UT and
radiography, thermography, air pressure testing).**
**⚠️ Snagging/punch lists and defects liability periods** — ⚠️ **and the honest observation
that latent defects (§8 → `building-structure-foundations-envelope-services-and-fire`'s moisture problems especially) appear years later, after the
defects period has expired.**