How Interior Design Actually Runs — The BIID Stages Explained

28 May 2026

Interior design is a staged process with defined outputs, not a mood board followed by shopping. Our interiors work follows the five BIID stages, and each one produces specific documents, requires specific decisions from you, and can be stopped at the end of.

That structure is the whole point. The projects that go wrong are almost never the ones where somebody chose the wrong fabric. They are the ones where a decision that belonged in stage two got made on site in stage five, when the joiner was already cutting.

Here is what actually happens.

The five stages at a glance

Stage 1 — Feasibility and Design Concept

This starts with a meeting on site wherever possible. Photographs and floor plans tell you a lot; they do not tell you how a room feels at four in the afternoon in February, where the noise comes from, or that the ceiling drops at one end.

The work at this stage is:

• Establishing the brief properly. Not "a calm family kitchen", but how many people cook at once, whether anyone eats at the island, where the dog sleeps, whether the room has to work for eight people twice a year, and what you already own that is staying.
• Understanding the constraints. Structure, services, ceiling voids, existing openings, listed or conservation status, and — in a commercial project — the operator's standards, brand requirements and the trading pattern of the space.
• Testing feasibility. Whether the thing you want will fit, function and pass the regulatory tests that apply.
• A concept. Spatial direction, material and colour direction, lighting character, and enough visualisation to make the direction discussable rather than abstract.

The deliverable is a decision, not a picture. At the end of stage one you should be able to say yes or no to a direction, and to have had an honest conversation about whether the budget and the ambition are in the same room. If they are not, this is the cheapest moment in the entire project to find out.

Where it goes wrong: skipping straight to selecting finishes. Selecting finishes before the layout is settled means selecting twice.

Stage 2 — Spatial Coordination

Stage two is where the concept becomes a real plan, and where the interior stops being a surface treatment and becomes architecture.

Everything gets coordinated against everything else:

• Layouts developed and tested — circulation, door swings, sightlines, furniture at real dimensions rather than symbols.
• Elevations for every wall that matters, because rooms are experienced vertically and plans hide problems.
• Lighting design — layers, positions, control zones, switch positions, and where the light actually needs to fall rather than a grid of downlights.
• Coordination with services: heating, ventilation, sockets and data, drainage runs, extract routes, and the ceiling void that everything competes for.
• Coordination with the structure and with the architectural design, where we are doing both.
• Visualisations — photo-realistic images, and where it helps, 360° VR so you can stand in the room before it exists.

This is the sign-off that matters most. After stage two, changing the layout means changing the drawings, the services, the joinery, the lighting and often the orders. Before stage two closes, changing it costs an afternoon.

Where it goes wrong: ceiling voids. In refurbishment work — and in hospitality especially — the single most common cause of late redesign is that the ducting, the sprinklers, the structure and the lighting all wanted the same slice of ceiling void. Coordinating it on a drawing is cheap. Discovering it on site is not.

Stage 3 — Technical Information and Documentation

Stage three produces the package that other people build and buy from. It is the least glamorous stage and the one that determines whether what gets installed resembles what was designed.

It contains:

• Setting-out drawings — exact positions of everything that has to be dimensionally right: tile datums, joinery lines, sanitaryware, sockets, wall lights, the centre line of a bath against a window.
• Joinery and bespoke details — sections through every bespoke item, at a scale the maker can work from.
• Finishes schedules — every surface in every room, named, referenced and specified with the supplier, product reference, finish and quantity.
• The FF&E specification — furniture, fittings and equipment, item by item, with dimensions, materials, upholstery, finishes, performance requirements and, for commercial work, the testing and durability standards the item has to meet.
• Samples and control samples — physical, seen under the actual lighting, signed off.

The specification is a contract document. Written loosely, it hands the choice to whoever is buying, and you get the cheapest thing that fits the description. Written properly, it is the reason the room looks like the visual.

Where it goes wrong: a specification that reads as a shopping list rather than a performance requirement. On commercial projects this is the source of most substitution disputes, which is why procurement control matters as much as specification — see our hotel interiors service.

Stage 4 — FF&E Purchasing

This is the stage that separates an interior design service from an interior design idea, and it is a procurement operation rather than a design one.

We issue purchase orders, arrange vendor cheques and payments, track the production cycle and carry out quality control before goods ship. In practice that means:

• Purchase orders as the control document — item, specification, finish, quantity, price, lead time, delivery address and delivery window, all in writing against the specification.
• Payment control — deposits and staged payments released against progress, not in advance of it.
• Production tracking — knowing where each order is in the factory, because a lead time quoted at order is a forecast, not a fact.
• Quality control — inspection against the approved sample before the goods leave the supplier. A defect found in the factory is a remake. The same defect found on site is a hole in the programme.
• Delivery sequencing and storage — goods arriving in installation order, into a place that is dry, secure and accessible.

Where it goes wrong: long-lead items ordered late. On a hospitality project the critical path frequently runs through a single upholstered item or a single bespoke light fitting. If the ordering schedule is not built backwards from the opening date, the programme is fiction.

Stage 5 — Project Administration

Design intent survives contact with a building site only if somebody is administering it.

At this stage we inspect the works against the drawings and specifications, answer the queries that come in from the contractor and the installers, review substitutions properly rather than reflexively, oversee installation and set-out, and run the snagging and handover.

Site queries are constant, and most of them are legitimate: something does not fit, something has been discontinued, a wall is not where the survey said it was. The value of this stage is that each of those gets an answer that has been thought about against the whole design, quickly, so the site does not stop and does not improvise.

Where it goes wrong: an interior designer who withdraws at the end of stage three. The gap between a beautiful drawing set and a delivered room is entirely made of decisions taken during construction.

How this sits alongside the architectural stages

Where we are doing both, the interiors run in parallel with the six RIBA design stages of the architectural work rather than after them.

The practical consequence is that the interior designer should be appointed early, not at first fix. Socket positions, ceiling voids, structural openings, drainage runs and window positions are all interior decisions being made on an architectural drawing. If nobody is representing the finished room while those are set, the room is compromised before anyone has chosen a colour.

This is the single most expensive misunderstanding in the field. Interior design is routinely treated as the last thing. It is more accurately the earliest thing that gets delivered last.

Where you can stop

We price a fixed fee for each stage. That is deliberate, and it means you can stop at the end of any stage with something usable in your hands.

• Stop after stage one and you have a tested concept and a realistic budget conversation.
• Stop after stage two and you have a coordinated design you could hand to someone else.
• Stop after stage three and you have a full documentation and specification package to build and buy from.
• Stages four and five are the delivery service, and they are where the design either happens or does not.

The same process, different pressures

The stages do not change between a private house and a hotel. What changes is the weight on each one.

On a private residential interior — our Luxury Bespoke Villa Interior in Beirut or the Stylish Living Area at Colton, South Norfolk — stages one and two carry the most weight, because the brief is personal and the decisions are individual.

On a commercial interior — our Contemporary Offices and Reception in Beirut — stages three and four carry it, because the space has to perform, comply, take heavy use, and open on a date.

Our interior design is directed by Joyce Baraké Chebli, who heads our Beirut office and oversees interior design across the Middle East, with over seventeen years in interior design internationally.

Start with a conversation

Our free initial consultation covers the site constraints, what you want the space to do, the planning or technical challenges, and next steps with indicative timelines. It costs nothing and it usually changes the brief.

See our interior design service, our hotel interiors work, or our fee structure. Book a free initial consultation, call +44 (0) 1508 830 310 or email info@archidite.com.