Write so another person can build, order or install it correctly.
A good specification removes assumptions. It identifies the exact item, defines the required finish and performance, explains where it goes, states what is included, and points to the drawing or schedule that shows its location.
01 · What a specification actually does
A specification translates design intent into instructions that can be priced, procured, manufactured and installed. Drawings show where something goes and how it relates spatially; the specification explains what it is, what quality is required, what finish is expected, and what conditions must be met.
“Oak veneer wardrobe.”
This leaves species, veneer cut, substrate, edge detail, sheen, stain, hardware and sample approval undefined.
Define the measurable intent.
Specify oak species/appearance, veneer cut, substrate, finish system, sheen, edge treatment, hardware, grain direction and approval sample.
If a contractor, joiner or supplier could reasonably make two different versions from your wording, the specification probably needs more information.
02 · Use a consistent specification structure
Keeping the same order on every item makes schedules faster to read and easier to quality-check.
03 · Writing rules that make specifications clearer
- Use one term consistently. Do not switch terminology unless the systems are genuinely different.
- Avoid vague adjectives. “Premium”, “high quality” and “durable” are not measurable requirements by themselves.
- Use dimensions and references. Replace “thin grout joint” with a defined or manufacturer-approved joint width.
- Separate intent from means and methods. State the required result unless the exact method is essential.
- Do not contradict manufacturer instructions. Proprietary products should follow current manufacturer requirements unless the project team agrees otherwise.
- Do not invent compliance claims. Verify fire, acoustic, slip, structural and other performance requirements.
“Submit representative sample / finish sample for designer approval prior to procurement or installation.”
04 · Product specifications
For furniture, sanitaryware, appliances, decorative lighting and other proprietary products, make the exact selection unmistakable.
| Field | What to include | Example |
|---|---|---|
| Manufacturer | Exact brand | Flos |
| Model | Full product name | Coordinates S2 Pendant |
| Finish | Manufacturer finish name/code | Anodised Champagne |
| Size | Selected variant | Selected size / as scheduled |
| Electrical | Verified controls / driver info if relevant | DALI-compatible where project requires |
| Location | Room + drawing reference | Dining room · RCP L-102 |
| Procurement | Lead time / supplier / substitution | Confirm availability before order |
URLs change. Store manufacturer, model, finish, code, dimensions and a product data sheet or screenshot in the project record.
05 · Finish specifications
Stone
- Stone type / commercial name.
- Finish: honed, polished, brushed, leathered, etc.
- Nominal thickness.
- Slab/tile size or “cut to shop drawings”.
- Vein direction/bookmatching if relevant.
- Edge profile.
- Sealer/treatment where specified.
- Actual slab approval before cutting where variation matters.
Timber + veneer
- Species and grade/appearance.
- Solid timber vs veneer.
- Veneer cut and matching method.
- Grain direction.
- Stain/tint reference.
- Sheen/coating system.
- Substrate and exposed edge treatment.
Paint
- Manufacturer/system where fixed.
- Colour code.
- Sheen.
- Substrate.
- Compatible preparation/primer.
- Sample panel for critical colours.
Tile
- Manufacturer, collection, colour and finish.
- Module size and thickness.
- Layout/orientation.
- Grout colour and joint width.
- Edge trim/profile.
- Wet-area/slip suitability where relevant and verified.
06 · Joinery + custom fabrication
Custom joinery needs coordination between the written specification and detailed drawings.
- Joinery drawing reference.
- Carcass/substrate material.
- Exposed face material and internal finish.
- Door/drawer thickness where design-critical.
- Edge treatment, reveals and grain direction.
- Handles/pulls or integrated opening detail.
- Hinges, runners and soft-close requirements.
- Ventilation for appliances/equipment.
- Stone/metal/glass interfaces.
- Service access panels.
- Shop drawing approval before manufacture.
- Finish sample approval before production.
Fabricate to drawing ID-J-407. Moisture-resistant substrate with oak veneer exposed faces; grain vertical to doors and horizontal to drawer fronts unless noted otherwise. Finish to approved sample, low-sheen clear protective coating. Concealed soft-close hinges and full-extension soft-close drawer runners. Coordinate basin waste, trap, wall outlets and removable access panel prior to manufacture. Submit shop drawing and finish sample for approval.
07 · Lighting specifications
Decorative and architectural lighting must coordinate with the electrical/lighting design.
- Fixture code matching the RCP.
- Manufacturer + model.
- Finish + size.
- Light source / lamp type.
- Colour temperature where design-critical.
- Beam angle where relevant.
- Dimming/control compatibility where verified.
- Driver location and access.
- Mounting type and height.
- Wet-area/IP suitability where relevant and verified.
Lighting schedule, RCP, switching/control plan and electrical drawings must agree.
08 · Hardware + fittings
- Door handles, knobs, pulls and backplates.
- Hinges, pivot systems and locks.
- Door stops.
- Cabinet pulls and integrated rails.
- Drawer runners.
- Wardrobe rails/internal accessories.
- Bathroom accessories.
- Metal finish coordination across related items.
Matching by colour name only.
“Brass” can vary dramatically between brands.
Set a finish hierarchy.
Identify a primary finish sample and require secondary items to be visually compatible with it.
09 · Performance requirements
Use performance criteria only when the project needs them and when they can be verified.
| Topic | When it matters | Verify |
|---|---|---|
| Fire | Commercial/hospitality, regulated finishes | Applicable local classification + product evidence |
| Slip | Bathrooms, terraces, entrances | Test classification accepted locally |
| Moisture | Wet areas | Waterproofing + substrate + product suitability |
| Acoustic | Hotels, apartments, offices | Consultant criteria + tested assemblies |
| Durability | High-traffic areas | Abrasion, staining, cleaning, warranty |
| Load | Shelves, stone, suspended items | Support, anchors, substrate, engineer/fabricator requirements |
Do not copy generic fire, slip, acoustic or structural values from another project.
10 · Coordination rules
When a client changes a product or finish, update the specification, drawing reference, FF&E schedule and procurement record together.
11 · Example specifications
Paint finish
Interior wall paint to Bedroom 01. Warm off-white; final manufacturer/code to approved sample. Matt finish. Prepare substrate in accordance with manufacturer requirements and achieve uniform colour and sheen. Apply approved sample area before full-room application.
Natural stone
Natural marble vanity top and splashback. Honed finish. 20 mm nominal slab thickness unless fabricator requires otherwise. Eased square edge. Vein direction to approved shop drawing. Fabricator to template on site after joinery installation. Submit actual slab images for approval before cutting.
Upholstery
Chair in manufacturer’s selected upholstery option. Fabric colour and texture to approved physical swatch. Confirm quantity, repeat, direction and suitability with upholsterer/manufacturer before order. Where project fire-performance requirements apply, supplier to provide relevant documentation before procurement.
Tile
Porcelain wall tile to shower and vanity walls. Finish, size and colour to approved sample. Install to elevation set-out. Grout colour to approved sample; maintain consistent manufacturer-appropriate joint width. Confirm tile batch and quantity before installation.
12 · Pre-issue QA checklist
Give the specification to someone who did not design the project and ask: “Could you order or build the correct thing from this information?” Every question they need to ask is a clue that the document can be clearer.