Building assemblies reference

Building Systems Encyclopedia

An educational reference to the assemblies a building is made of — how each one is organised, what role every component plays in it, how those components interact, and which junctions with adjacent systems the design actually turns on.

Every entry is written on one principle: a system is more than its parts. How it behaves depends on climate, jurisdiction, loading, substrate, the systems it meets, the way the building is used, the manufacturer's instructions and qualified professional design. Nothing here is a specification, a calculation, a detail drawing, a compliance determination or a recommendation.

121 system entries · 13 categories · no prices, no ratings, no rankings, no brands, no suppliers

Three references, three different questions

These sections sit next to each other and are easy to confuse. They answer different questions, and each one is the wrong place to look for the other two.

Building Systems — this section

Reference entries about an assembly. Answers “how is this assembly organised, and which parts depend on which?”

Materials Library

Reference entries about a single material or product format. Answers “what is this material, and what does it depend on?”

Materials guides

Planning guides and neutral A-vs-B comparisons. Answers “how do I choose between these?”

Browse by group

Systems by part of the building

Four groups: what holds the building up, what separates inside from outside, what divides and lines it internally, and where water goes once it lands. The groups are a reading order over the same categories — they add no pages of their own.

Structure and support

The load path from the ground upwards — foundations, primary frames and load-bearing walls, floor decks, and the structures that hold retained ground back. · 37 entries

7 entriesFoundations & Ground →Assemblies where a building first meets undisturbed ground — strip, pad, raft and piled foundations, pile caps, ground improvement and ground gas protection.15 entriesFrames & Load-Bearing Walls →Complete primary load paths from roof to foundation in masonry, timber, steel and concrete, together with the stability system without which none of them stands up.7 entriesFloor Structures →Horizontal decks read together with the stack placed on them, told apart by what spans, what is infill and what is only a topping over both.8 entriesBelow Ground & Retaining →Assemblies built against retained ground, where lateral earth pressure and the water held in that ground decide the design together rather than one at a time.

Building envelope

Everything separating inside from outside: the continuous control planes, the walls and roofs they run through, the skins hung on those walls, and the junctions between. · 46 entries

7 entriesControl Layers →The continuous planes running around an enclosure — air, vapour, water and heat — and the interruptions that decide whether that continuity actually exists.7 entriesExternal Wall Build-Ups →Complete external walls read as a layer order: where in the thickness of the wall water is stopped, and in which direction the wall is allowed to dry afterwards.8 entriesFacades & Cladding →Outer skins carried on a wall that is already complete behind them, where the support, the joint and the cavity carry the durable knowledge rather than the finish.15 entriesRoof Assemblies →Roofs answering two questions at once: where the insulation sits relative to the deck, and how the water-shedding layer achieves continuity across the whole surface.9 entriesJunctions & Terminations →The places where continuous layers stop, turn, change plane or are pierced, and several duties collide inside a very small amount of construction.

Interior assemblies

Elements built inside a completed shell — partitions, linings, ceilings and wet areas, and the assemblies built specifically to separate one occupancy from another. · 14 entries

8 entriesPartitions & Linings →Internal elements whose behaviour comes from the framework, the void and the perimeter behind them rather than from the board or tile on the visible face.6 entriesAcoustic Separation →Assemblies defined by the transmission path each is built to defeat — airborne, impact, flanking or over the head of a partition — rather than by what they are made of.

Water and external systems

Where water goes once it lands, and the external surfaces people walk on that it has to pass through, over or around on the way. · 24 entries

11 entriesDrainage & Rainwater →Stages in the single route water takes from the surface it lands on to the point it leaves the site, each one defined by where it hands the water on.13 entriesDecks & Paving →External surfaces people stand on, plus the substructure, edge, support and guarding that make one usable, each decided by the layer beneath and the route its water takes.

Elsewhere on Build Design Hub

Where to go next

This encyclopedia explains how assemblies are organised. These sections cover the materials inside them, the choices between them and the preparation around them.

Materials Library →The material entity encyclopedia: what a specific material or product format is, and what its behaviour depends on.Materials planning guides →The choosing-and-comparing side: planning guides, application guidance and neutral A-vs-B comparisons.Construction guides →How the stages that build these assemblies are planned and sequenced.Renovation guides →Working with assemblies that already exist, including what is hidden until opened up.Planning checklists →Owner-side preparation before the conversation where an assembly is decided.Questions answered →Plain answers to the questions owners ask before and during a project.

What this encyclopedia is not

It is not a marketplace, a supplier directory or a brand comparison. No product, manufacturer, supplier, installer or proprietary system is named, rated, ranked or recommended anywhere in it.
It is not a design service or an engineering database. There are no calculations, spans, load capacities, reinforcement or fixing schedules, layer thicknesses, dimensions, falls or gradients, and no drainage, HVAC or electrical sizing.
It carries no prices, no cost comparisons, no service-life figures and no fire, acoustic or thermal ratings, classes or values.
It does not determine whether an assembly complies with any requirement, is structurally adequate, is weathertight or is permitted in any jurisdiction. Those are matters for qualified professionals and the relevant authority.
It is not an installation guide. Method, sequence and workmanship belong to the manufacturer's instructions and the trades carrying out the work.

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