Homestead Site Structure And Materials

---
name: homestead-site-structure-and-materials
description: "Use when siting a house, planning ground investigation, choosing a foundation, orienting for solar gain, or selecting a structural system and material. Covers bearing capacity and differential settlement, the gravity load path, shear walls and hold-downs, and a full comparison of timber, masonry, reinforced concrete, mass timber and steel. Part 1 of the Building a Homestead reference."
---

# Site, Structure and Material Selection

> **Part 1 of 8** of the *Building a Homestead* reference (plugin `building-a-homestead`), covering
> §1–§3 — ground investigation, solar orientation, the gravity and lateral systems, and choosing a structural material. Sibling skills:
> `homestead-envelope-and-building-physics` (§4–§5 — the four control layers in priority order, drying potential, and the materials that make them up),
> `homestead-services-sequencing-and-codes` (§6–§7 — MEP, fire safety, the order the trades run in, permitting, and the house build checklist),
> `homestead-livestock-digestion-nutrition-and-species` (§8–§10 — why cattle are different, the nutrient requirements that follow, and picking a species),
> `homestead-livestock-housing-health-and-grazing` (§11–§14 — fencing and shelter, biosecurity, reproduction, and the grazing systems with their trade-offs),
> `homestead-soil-and-fertility` (§15–§16 — what soil actually is and how to feed it without wrecking it),
> `homestead-crops-rotation-pests-and-water` (§17–§22 — crop production, why rotation does several jobs at once, IPM, irrigation methods, and an honest look at farming systems),
> `homestead-reference` (§23–§24 — the terms of art across all three domains, and the books that actually teach this),
>
> Section numbers are **shared across the whole set**: a reference written as §N → `skill` points
> into that sibling skill. Building work is governed by local codes and inspection, and livestock by
> local animal-health rules; this reference tells you what to design for and what to ask, not what
> your jurisdiction permits.

## Part I framing — what a building actually is

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.

The organizing reality for anyone building a house:

- Design decisions bind cost early and irreversibly.
- Water destroys more buildings than structural failure (§4 → `homestead-envelope-and-building-physics`).
- Load paths and lateral systems are the two things a structure must get right.

> **THE COST-INFLUENCE CURVE**
> The ability to influence cost is highest at the start and collapses as design progresses, while
> expenditure does the opposite. By the time construction begins, most of the cost is locked in.
> This is why late "value engineering" usually means removing quality rather than finding
> efficiency. Spend time on design decisions before you spend money on materials.

## §1 Site and Ground Investigation

The ground is the material you did not choose and cannot fully inspect, and **it is the largest
single source of construction claims**. Before committing to a design, you must understand what you
are building on.

**Site investigation process:** desk study (geological maps, soil surveys, flood maps) → walkover
(look for slopes, drainage, rock outcrops, vegetation patterns) → boreholes or trial pits (sample
the actual subsurface) → lab testing (bearing capacity, plasticity, compaction) → geotechnical
report.

> **YOU SAMPLE A HANDFUL OF POINTS AND INTERPOLATE AN ENTIRE SITE**
> "Differing site conditions" clauses exist because ground investigation is genuinely uncertain,
> not because someone was lazy. The cost of additional boreholes is trivial against the cost of a
> foundation redesign after construction starts. For a house, at minimum get trial pits or borings
> at the building footprint corners and center. If you are on expansive clay, on a slope, or in a
> flood zone, get a proper geotechnical report.

### What matters about your ground

| Property | Why it governs |
|---|---|
| Bearing capacity | How much load the soil can support |
| Differential settlement | What actually damages structures — uniform settlement mostly does not, but one corner settling more than another cracks everything |
| Groundwater level | Affects foundation design and basement waterproofing |
| Expansive or shrinkable clays | Swell and shrink with moisture changes, cracking foundations |
| Liquefaction potential | In seismic zones |
| Contamination | Affects disposal, remediation and use |
| Made ground | Fill that may be uncompacted or contain undesirable material |

### Site context to evaluate

Access for construction vehicles and later for fire trucks; neighbors and party wall obligations;
rights of light; flood risk; microclimate (wind exposure, solar orientation); and existing
underground utilities. **Utility strikes are a recurring cause of injury and delay — call before you
dig, every time.**

## §2 Orientation and Solar Design

In the northern hemisphere, orient the **long axis of the house east-west**, with most windows on
the **south** side for winter solar gain. Overhangs on the south face block summer sun (high angle)
while admitting winter sun (low angle).

This single design decision reduces heating and cooling costs for the life of the building at zero
ongoing cost. **In hot climates, prioritize shade and cross-ventilation over solar gain.**

## §3 Structural Systems and Material Selection

A structure does two jobs: **carry gravity down, and resist lateral load without falling over. The
second is what usually governs the design.**

### Foundations — where the load path terminates

Shallow versus deep is decided by what is at depth, not by preference. The foundation transfers the
building's load to competent ground.

- **Shallow foundations:** pad or spread footings under individual columns; strip footings under
  load-bearing walls; or a raft/mat foundation that spreads the entire building load across the
  footprint (used on weak or variable ground). Most houses on decent soil use strip footings or a
  raft slab.
- **Deep foundations:** driven piles (displacement, noisy, good verification from driving records)
  or bored piles (quiet, large capacity, harder to verify) — used when the upper soil layers cannot
  support the load and you need to reach stronger material at depth.

**The scale of the thing, for a house on ordinary ground:** strip footings in the region of
**600–900 mm wide and 300–450 mm deep**, bearing on undisturbed soil **below the local frost line**,
with a **150–200 mm** reinforced concrete ground beam. On expansive clay, a stiff raft or
post-tensioned slab. On slopes, stepped footings or a split-level design.

> **THOSE NUMBERS ARE AN ILLUSTRATION, NOT A DESIGN**
> Read them as the order of magnitude a house foundation lands in, and nothing more. Footing width
> follows the load above divided by the allowable bearing pressure of *your* soil; depth follows
> frost penetration, the groundwater table and the depth at which competent material actually
> starts; reinforcement and ground-beam sizing follow the spans, the variability of the ground and
> the seismic and wind demand the building must carry down. Any one of those can move the answer by
> a factor, in either direction — and an under-designed foundation is a differential-settlement or
> collapse problem, not a snagging item. **"Reasonable ground" is not a soil report.** The bearing
> capacity comes from a geotechnical investigation of the site, the dimensions come from a
> structural engineer working to your local code, and both are checked by the authority that
> inspects the work.

> **WATER IS THE RECURRING FOUNDATION PROBLEM**
> Buoyancy and uplift on basements (a lightweight basement can literally float), dewatering and its
> effect on neighbors' settlement, and waterproofing. If you have a basement, waterproofing is not
> optional — it is a design discipline. Use tanking (external waterproofing), a drained cavity
> system, or water-resistant concrete, and plan for the case where the water table is higher than
> you think.

### The gravity system

**The load path: roof → walls → floor → beams → columns → foundation.** Every load needs a
continuous route to the ground. An interrupted path — a removed wall, a beam that nobody designed,
an opening cut without a header — is how buildings fail. **Trace every load from roof to ground
before you build.**

For a typical house the gravity system is: roof trusses or rafters spanning onto exterior and
interior load-bearing walls; floor joists spanning onto walls or beams; walls carrying load down to
the foundation.

- **Timber frame:** dimensional lumber (2x4, 2x6, 2x8, 2x10, 2x12) sized by span tables in the
  building code.
- **Masonry:** the walls carry the load in compression.

### The lateral system

**Wind and seismic loads are the ones that govern structural design.** For a house, the lateral
system is typically **shear walls** — plywood or OSB sheathing nailed to the wall framing, which
resists racking forces and transfers them to the foundation. **Metal straps and hold-downs anchor
the walls to the foundation against uplift and overturning.**

> **A PARTIALLY BUILT STRUCTURE HAS NO LATERAL SYSTEM**
> Until the diaphragms (floor and roof sheathing) and shear walls are in place, the structure has no
> lateral resistance. **Temporary bracing is not optional during construction.** Steel frames must be
> braced during erection. This is why building sequencing matters — you cannot skip steps.

### Material selection for a house

| System | Typical Use | Pros | Cons |
|---|---|---|---|
| Timber frame | Most US houses | Fast, familiar, renewable, easy to modify | Fire and moisture sensitive, span limitations |
| Masonry (brick/block) | UK, Europe, much of world | Durable, thermal mass, fire-resistant | Compression only, needs lateral system, labor-intensive |
| Reinforced concrete | Foundations, slabs, some walls | Strong, durable, fire-resistant | Embodied carbon, needs formwork, curing time |
| Mass timber (CLT) | Growing in residential | Renewable, fast erection, fire-resistant (chars predictably) | Moisture protection during construction, cost |
| Steel frame | Spans, connections | Long spans, fast erection, precise | Needs fire protection, corrosion protection, cost |

The material properties behind these trade-offs — concrete w/c ratio and cover, wood moisture
content and movement, steel connections and corrosion, masonry movement joints — are in
§5 → `homestead-envelope-and-building-physics`. Structural fire resistance by material is in
§6 → `homestead-services-sequencing-and-codes`.

### Serviceability

**A structure can be strong enough and still be unusable.** Deflection (floors bouncing or sagging),
vibration (floor vibration in long spans is a common and expensive complaint), crack control, and
drift limits all govern.

Size floor joists for **deflection and vibration, not just strength** — the code span tables do this
for you, but if you are engineering custom spans, check both. Anything beyond the prescriptive code
tables needs an engineered design stamped by a licensed structural engineer
(§7 → `homestead-services-sequencing-and-codes`).

## Before you commit to a design

- Get a soil test and geotechnical report — trial pits or borings at the footprint corners and
  center as a minimum.
- Orient for solar gain and natural ventilation before the plan is fixed.
- Trace every gravity load from roof to ground, and confirm a lateral system exists on both axes.
- Check zoning, setbacks, height limits and permitting requirements
  (§7 → `homestead-services-sequencing-and-codes`).
- Resolve the four control layers — water, air, vapor, thermal — at every transition before
  construction (§4 → `homestead-envelope-and-building-physics`).
- Inspect foundations before pouring: verify reinforcement placement, cover, and formwork.
- Inspect framing before closing: verify load paths, lateral bracing, hold-downs.