What is an architectural specification?
An architectural specification is the written document that sits beside the drawings and defines the quality of a building. It names the materials and products, the Australian Standards they must meet and how the work is carried out and judged. The drawings show where everything goes and how it fits together, while the specification sets the standard it is built to.
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What does a specification do that drawings cannot?
Many design decisions simply cannot be drawn. A line on a plan can show where a floor changes from timber to stone. It cannot say which grade of oak is used, how it is fixed or what finish protects it. NATSPEC, the national specification system owned by government and industry bodies, explains that the drawings and the specification complement each other. Together they carry the design intent from the architect's desk to the people building on site.
NATSPEC describes the specification's primary job as defining precisely the quality required and the processes needed to achieve it. That one document then does several jobs at once. It records design decisions, shows how the work meets the law and lets builders price and tender the project. It also becomes part of the contract, guides the trades on site and settles questions if a dispute arises.
What goes into a house specification?
A specification can describe a product or a piece of work in four recognised ways. It can refer to a published document such as an Australian Standard or a manufacturer's technical manual. It can state the performance a product must achieve, describe the materials and workmanship in detail or name a specific branded product.
Most specifications are organised by trade or element, with sections for concrete, framing, roofing, joinery, tiling and so on. NATSPEC sections typically cover general requirements, the products themselves, how the work is executed and the selections made for the project. For houses, NATSPEC publishes a domestic package used by architects and building designers for new dwellings and alterations. On a simple home, many selections may sit on the drawings instead. On a custom home, the specification often runs alongside detailed schedules of finishes and fittings, which our new home selections checklist helps you organise.
Why does the specification matter in your contract?
In NSW the specification carries real legal weight. Under the NSW rules for home building contracts, a contract must have its plans and specifications attached and they are taken to form part of the contract. Any agreement to vary the plans or specifications must be in writing and signed by both you and the builder.
The statutory warranties lean on it too. The builder warrants that the work will follow the plans and specifications in the contract and that materials will be new unless otherwise specified. Before building starts, the council or a registered certifier must also be satisfied that the plans and specifications comply with the Building Code of Australia. A thin specification therefore leaves you with less to rely on if the finished work falls short.
What should you check before you sign?
Read the specification with the drawings open beside it. Look for vague phrases such as "or equivalent" and "to builder's standard" against items that matter to you and ask what they mean in practice. Check that the products you chose appear by name or by a clear performance standard.
Watch for allowances, prime cost items and provisional sums, because they show where the final price may still move. Finally, ask how a conflict between the drawings and the specification would be resolved, since your contract should set out which document takes priority.
How we prepare specifications at SHORE
At SHORE Design + Build the working drawings, specifications and schedules are prepared by the people who will build from them. Our builders share a studio with our architect and interior designers. Every junction is drawn and specified with the carpenter who will stand in front of it in mind.
Once that documentation is complete, you receive a fixed lump-sum contract price based on it. If you already have an architect's documents, our guide to building from an architect's plans explains how we review them. To see how the whole process runs under one contract, explore design and build in Sydney.
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