What an Architect Actually Does During the Construction Phase

A plot owner in New Town usually calls us at a very specific moment, which is somewhere just after the sanction has come through and the contractor has handed over a quotation, and the question is almost always some version of whether an architect is still needed now that the drawings are finished. It is a fair question and it deserves a straight answer, so here it is: the drawings were the cheaper half of the work, because a sanctioned plan is a description of a building and not the building itself, and almost everything that decides whether the house you end up with matches the house you paid for happens in the eighteen to thirty months that follow.

We have been running an architecture and interior design practice out of New Town since 2014 and have delivered 330 plus buildings across New Town, Salt Lake, Rajarhat and greater Kolkata, and the pattern we see most often is not a bad design, it is a good design that quietly drifted on site because nobody senior was standing between the drawing and the mason. A column gets shifted nine inches because a bar bender found it convenient, a sunk slab in the toilet does not get sunk because that instruction lived in a detail nobody printed, a window head drops by four inches to match a shutter the fabricator already had, and none of these are dramatic on the day they happen, but stack twenty of them across a G+3 and the house stops being the house you approved.

So this piece is a plain walkthrough of what an architect actually does once construction starts, written the way we run it, because if you are about to sign a fee agreement you should know exactly what you are buying in that second phase and what it costs you to skip it.

The construction phase starts before a single brick is laid

The first thing that happens after sanction is not digging, it is translation, because the drawings that satisfy an approval authority are not the drawings a contractor can build from. A sanction set establishes coverage, setbacks, heights and the legal footprint, and it is deliberately economical, whereas a working set has to answer questions the sanction never asked, like where every plug point sits, how deep the toilet sunk is, what the beam bottom level is in the living room so the false ceiling clears the window, and which wall carries the concealed plumbing shaft. On our residential architecture projects this working set typically runs several times the page count of the sanction set, and it is the single biggest determinant of how few arguments you have on site later.

Alongside that, we mark out the building on the actual plot with the contractor and the structural consultant present, and this is the visit we never let anyone skip, because paper north and site north disagree more often than people expect, boundary walls are rarely where the deed says they are, and the setback you were granted has to physically exist on the ground and not just in a PDF. We have caught plots in Action Area II where the neighbour's compound had crept in by roughly a foot and a half, and finding that on day one costs a conversation, whereas finding it after the plinth is cast costs a demolition.

The other pre construction job is sequencing, so we set out what has to be decided by when, and this matters because the expensive decisions in a Kolkata build are not the ones people worry about. Tile selection can wait, but the electrical layout cannot wait past brickwork, the kitchen platform height and appliance plan has to be frozen before plumbing goes into the wall, and if you are planning a modular kitchen or a serious false ceiling and lighting scheme later, those decisions have to be pulled forward into the structural phase or you will be chasing walls with a chisel afterwards.

What the site visit is actually for

A site visit is not an inspection in the ceremonial sense, it is a checkpoint tied to a stage, and the stages that matter are the ones where a mistake becomes permanent. Before a slab is cast we check reinforcement against the structural drawing, cover blocks, the position of every sleeve and cutout, the electrical conduits laid in the deck, and the sunk portions, because once that reinforced concrete is poured you are living with whatever is inside it for the life of the building. Before plaster we check that openings match the schedule, that the plumbing lines have been pressure tested, and that the concealed boxes sit where the furniture layout expects them rather than where the electrician found it easy.

The catch here is that a lot of what an architect looks for on site is invisible in a photograph, so the WhatsApp update culture that has taken over Kolkata construction genuinely does not substitute for it. You cannot see cover depth in a photo, you cannot judge whether a wall is plumb from a phone camera, and you certainly cannot tell from a picture whether the waterproofing treatment in the terrace and toilet sunk was done in the right sequence with the right slope, which in a city that takes the volume of rain Kolkata takes is not a detail you get a second attempt at.

There is also a running design job through all of this, because no build survives contact with reality unchanged. A neighbour's construction changes the light on your east face, a client's parents move in and a ground floor bedroom becomes necessary, the market runs out of a stone you specified, and each of these needs a decision that holds the design together instead of patching it. That is the part that is hard to write into a scope document and is exactly what you are paying a principal architect for.

Coordinating the people who are not you

On an average independent house in New Town or Salt Lake there are somewhere between eight and fifteen agencies involved across the build, counting the civil contractor, the structural consultant, plumbing, electrical, the aluminium or uPVC fabricator, the grill and railing fabricator, waterproofing, tiles and stone, painting, the lift vendor on taller plots, and later the interiors and furniture teams. None of them read each other's drawings and none of them are incentivised to, so the coordination is real work.

The classic Kolkata collision is the lift shaft versus the staircase headroom, closely followed by the AC copper line routing versus the beam layout, and then the shaft that the plumber sized for his pipes without knowing the electrical riser was meant to share it. Our job is to see these on paper months before they happen on site, and where a client wants to be certain about how a space will feel before it is built, we run 3D visualisation and rendering at the same time so the decision is made looking at the room rather than at a plan.

The money side, which is where most disputes actually start

Somebody has to check that what is being billed is what was built, and if that somebody is you, the arithmetic will beat you eventually, because running bills in construction are measurement documents and not invoices. We verify quantities against measured work, we check that the item rates match what was tendered, we watch for the same square footage appearing under two heads, and we certify only what has been executed to specification, and that certification is what protects the payment schedule from becoming a negotiation every month.

Material substitution is the quieter version of the same problem, so a specification that says a particular cement grade, a particular steel brand, a particular tile thickness and a particular hardware series exists precisely so that a substitution has to be asked for rather than assumed. When a client asks us why the fee structure looks the way it does, this is usually the part of the answer that lands, and we have written about it in more depth in our note on architect fees in Kolkata, alongside the realistic budgeting picture in the cost to build a house in New Town guide.

Sanction is not the last time you deal with the authority

A lot of owners assume the approval story ends when the plan is sanctioned, and then discover at the end of the build that the completion and occupancy stage has its own set of requirements, its own drawings and its own site verification, and that any drift between the sanctioned plan and the built structure surfaces right there. Sumana Kumar, our principal architect, routinely takes residential and commercial projects through the NKDA, KMC and Bidhannagar Municipal Corporation building plan sanction processes and has deep working familiarity with how each of those bodies reads a file, and the practical consequence of that familiarity is that we build to the sanctioned drawing rather than building freely and hoping the paperwork catches up.

If you want the specifics of that back end, the NKDA building plan sanction process guide covers the front half and the completion and occupancy certificate guide covers what the end of the build demands, and we have a separate breakdown of what architects actually handle during NKDA plan approval for owners who want the division of responsibility spelled out before they sign anything. For projects in a Bidhannagar jurisdiction the rules differ in ways that matter, particularly around coverage and open space, so the same discipline applies with a different rulebook.

Handover is a process, not a day

The last stretch of a build is where fatigue does the most damage, because by then everyone wants to be finished, and that is exactly when snags get waved through. We run a written snag list room by room, we hold back the final certification until it is closed, we collect the warranties and the as built drawings for concealed services so that the next person who opens a wall knows what is behind it, and we walk the house with the owner rather than handing over a set of keys and a smile.

If interiors are part of the scope, the transition matters too, because a house that has been built with the interior design already resolved needs far less breaking and rebuilding than one where the two phases were run by strangers, and the same logic is why we treat renovation and remodelling of older Salt Lake and Kolkata houses as a structural exercise first and a finishes exercise second. You can see how this plays out over a full project in our DE Block residence in New Town, where the construction stage decisions are what made the finished spaces work.

At the end of the day, the construction phase is where an architect either earns the fee or does not, and the difference shows up years later in the way a slab behaves through a monsoon, in whether the toilets stay dry, in whether the doors still shut cleanly, and in whether the building on your plot is recognisably the one you approved. If you are holding a sanctioned plan and about to start construction in New Town, Salt Lake, Rajarhat or anywhere in greater Kolkata, talk to us before the first pour rather than after it, because that is the point where we can still change the outcome instead of only explaining it.