What's included in an interior design project: a stage-by-stage breakdown

What's included in a design project: a short list

An interior design project includes four mandatory blocks, and each is not an abstract stage but a specific document the client ends up holding.

The technical brief. The result of measuring the property, analysing the building services, functional zoning and a concept with references: a bound A3 document that the client signs off before further work begins.

The concept design. The layout, monochrome 3D sketches of the space's geometry, the selection of materials and equipment, and the final 3D visualisation with lighting design.

The technical documentation. A full set of drawings, diagrams, construction details and schedules: a document coordinated with the building services design, which the builders and contractors use to carry out the work without room for free interpretation.

The schedule (procurement). A table listing every item in the project: materials, furniture, equipment, prices and links to suppliers. It isn't tied to a single stage: it starts back at the technical brief and is closed about a week after the technical documentation is delivered.

What follows: what lies behind each block, and what the project does not include on principle.

The technical block: measurements and the technical brief

The first block isn't a formality, it's the foundation the whole project rests on. It starts with a meeting and a questionnaire: the designer finds out how the family will actually live in the space, what habits and priorities they have. Next comes getting to know the property, taking measurements and producing a measured survey, photographing the current condition, and analysing the building services: what's already in place, what can be relocated, where the constraints are.

This same stage is where the functional zoning takes shape and, importantly, where the concept and its style references are set. Unlike the simplified “layout first, style later” scheme, the concept is already laid down in the technical brief: the concept design that follows develops that same concept rather than inventing a style from scratch.

The result of this block is a bound A3 document that the client reviews and signs off. For a project of around 100 m², the technical brief takes an average of about two weeks; usually a single site visit is enough for measurements, with a repeat visit needed only for complex or large properties.

Layout and zoning

The layout is the first part of the concept design. The designer proposes zoning options, usually two or three to choose from, each with its own logic for furniture layout and scenario for using the space. The client compares the options and approves the final scheme, which becomes the basis for the visualisation that follows.

If the client's task is only zoning and layout, without visualisation and technical documentation, that's a separate, faster product: a space-planning project. A full design project goes further: it turns the approved layout into a three-dimensional solution with materials and working drawings.

3D visualisation: what the future interior looks like before work begins

Once the layout is approved, the geometric design begins, first as monochrome 3D sketches, which show the volume and proportions without colour or materials. At this stage it's easier to see and correct proportions than after materials and lighting have already been added to the model.

Next comes the selection of materials and equipment, a brief for the visualisation, and the final 3D visualisation with lighting design: lighting scenarios are worked out not separately, but together with the interior image. The client sees the space as it will look before any money has gone into construction. For a project of around 100 m², the whole concept design, layout and visualisation together, takes from 20 working days; more elaborate styles with a lot of decor and made-to-order furniture take longer.

Technical documentation: drawings for the building crew

The technical documentation is the block that sets a design project apart from a pretty picture. It's a full set of drawings, diagrams, construction details and schedules: floor plans, ceiling plans, socket and switch layouts, wall elevations, drawings for custom-made furniture, and details for the more complex solutions, from decorative surrounds to built-in lighting. The documentation is coordinated with the property's building services, so that the electrics, ventilation and plumbing don't clash with the design during installation.

For a project of around 100 m², the technical documentation takes around 20 working days. The overall benchmark for the whole cycle, from the technical brief to the delivery of the technical documentation, is about 2.5 months, given prompt approvals from the client; for other floor areas and styles the timeline shifts, and that's worth discussing in advance, not after the fact.

Technical documentation is the only language the designer, the site foreman and the subcontractors all read the same way. Projects where the renovation starts before this documentation is ready almost always end up needing rework: without drawings, the crew works from its own experience rather than from the decision the client approved.

Schedules and material specifications

The schedule is a table listing every item in the project: materials, furniture, equipment, decor, with prices and links to suppliers. It doesn't appear as a single file at the end: it starts back at the design-brief stage, grows alongside the concept design and the technical documentation, and is closed with a final version about a week after the technical documentation is delivered.

The schedule answers the question “exactly what needs to be bought and how much it will cost”, but not the question “who's going to buy it and bring it in”. The actual purchasing, logistics and delivery control are a furnishing and procurement service, which logically continues the design project, but is arranged separately.

What isn't included in a design project

Three items consistently aren't included in an interior design project, and they're worth discussing with the designer before work starts, so they don't come as an unpleasant surprise:

• Construction and installation work. A project is documentation and decisions, not a crew and not a cost estimate for the renovation.
• Purchasing materials and furniture. The schedule names the items and prices, but doesn't buy, deliver or track deliveries: that needs a separate furnishing and procurement service.
• Securing official approval for a reconfiguration. The layout is the basis for approval, but the studio doesn't include filing the paperwork and dealing with the authorities as part of the project.

Worth mentioning separately is design supervision: checking that construction matches the approved project is also not part of the design project, and it is arranged as a stand-alone service once the technical documentation has been delivered.

The split is honest and deliberate: a design project answers the question “how it should be”, rather than taking on the building work, the purchasing and the negotiations with the developer. None of these adjacent tasks is an add-on; each is a separate area of expertise with its own responsibility.

An example: what a design project looks like in practice

In the end, the client doesn't receive a single file but a set of different documents: a bound A3 document with measurements and the concept, a folder of monochrome 3D sketches and final visualisations, a package of working drawings with construction details and elevations, and a working version of the schedule that keeps being updated right up to delivery. These are different formats for different tasks: the concept document makes the case for the idea and gets it approved, the visualisation shows the result, the drawings talk to the builders, and the schedule keeps the budget under control.

For more on the stages and timelines that make up the whole journey, from getting to know the site to handing the project over for construction, see the article “Interior design project: a full breakdown”. And if it's this exact set of documents you need for your own project, the “Interior design project” service page describes the packages and terms of work.