How Do an Interior Architect and a Contractor Divide the Work?

What is the division of work between an interior architect and a contractor?

In the usual arrangement the interior architect draws the project and the contractor builds it on site; one decides how it looks, the other how it gets built. But this is not the only arrangement: drawing and execution can also sit in one team, and the division of work is then set up differently from the start.

The interior architect prepares the materials, dimensions, colours and detail drawings, and holds the whole space together under one language. The contractor carries the drawing to the site, managing the labour, the material orders and the site schedule. When the two roles sit with different parties, there is a handover between them; the drawing ends on one side and the execution begins on the other.

That handover has a cost. The same drawing can be read differently by each side; a measurement difference found on site needs correspondence or a meeting between the two parties to settle; and when something goes wrong, the question "was the drawing incomplete or the execution wrong?" stays open. Good interior architect and contractor pairs manage this with regular meetings; it is still a coordination load, and it gets lighter the more clearly the interior architect-contractor division of work is drawn.

The word "contractor" can mean two different jobs here. In a new building, the contractor who builds the shell does one job; the contracting that completes the finishing works (drywall, paint, floor finishes, electrical and mechanical) after the shell is done is another. Fit-out contracting for finishing works is the second one, and it is the one we take on.

We do not have to separate these two roles: on a job where we draw the interior project, we can also take on the contracting of the finishing works. We described the scope of this interior architect design and execution combination on our General Contracting page; it runs from site setup and occupational health and safety to the final tests before handover.

Who makes the decision when drawing and execution are separate, or in one hand?

Design decisions (material, colour, dimensions, lighting points) come from the interior architecture side in both arrangements; the difference is who holds the execution decisions. The table below shows how responsibility is shared in the two setups of the same job.

The second setup in the table applies only to the finishing works within our contracting scope. If the shell is with another contractor, coordination with them is still needed on shared matters such as services and floor levels; being in one hand does not remove that coordination, it only removes the handover between the drawing and the execution.

When do the interior architect and contractor sit at the same table?

When the work is run separately, the interior architect and the contractor meet at least once before the shell is finished, settling plumbing, ducting and floor finish decisions together.

These decisions are taken together rather than one after another because they affect each other. The duct route determines the ceiling height, the thickness of the floor finish determines the level under the door, and the position of the lighting points determines the route of the electrical installation. If one is decided in the drawing and the other is only learned later on site, a finished surface may have to be opened again.

The meeting usually covers which wall and which ceiling level the ducts will pass through, what thickness the floor finish will be laid at and how that affects the levels under the doors and in neighbouring rooms, and in what order the lighting points will be wired. The decision is written into the minutes or the drawing, so the same subject is not argued a second time on site.

We also explained why this meeting happens before the shell construction stage in our Underfloor Heating, Air Conditioning and Ventilation in a Villa article; that one explains the mechanical side, this one explains the division of work.

When the drawing and the finishing works are in one hand, this meeting stops being a separate event: the duct route and the floor thickness are both drawn at the design stage, with the knowledge of the team that will execute them. If the shell is with another contractor, shared decision points with them remain; only the number of parties at the table gets smaller. The decisions in the drawing are then not reinterpreted on site, and if a change is needed, the decision does not have to wait.

When does it make sense to separate drawing and execution, and when to combine them?

Separating drawing and execution suits new buildings with the shell still going up; combining them suits finishing works that should end with a single point of contact. Separating also suits a client who already has a team they trust.

The gain of separating is independence: you can choose the executor through different offers and keep the interior architect as a separate pair of eyes supervising the execution. Separating means that the party doing the work and the party checking it are different, and some clients want exactly that balance. The cost is the handover and coordination load described in the previous sections.

The gain of combining is the arrangement that turnkey interior architecture promises: the price and the date are written before the work starts, and the work arrives finished and with a single point of contact. The cost is that comparing offers becomes harder and that the scope has to be written down; if the scope grows, the price is discussed again. We explained this model in more detail in What Is Turnkey Interior Architecture?.

In Bilkent we combined the two: on the Bilkent Konut Projesi we carried out both the drawing and the on-site execution. Which one you choose depends on the scale of the job, on who holds the shell, and on how much of a single point of contact you want; both give a good result when run well. It helps to ask these questions before deciding: who holds the shell, is the scope written down, and were the delivery date and the price settled before the work started?

Umut GÜRLER is an interior architect and a graduate of Çankaya University Interior Architecture; he has worked since 2009 (more than 17 years) on villa, office and clinic interiors in Ankara, and his office is in Cepa Ofis Kule. The example in this article comes from a villa project whose drawing and execution he carried out himself.