Working Drawings and GFC Sets for a Salt Lake Build

Working Drawings and GFC Sets for a Salt Lake Build

If you have a sanctioned plan for a plot in Salt Lake and you are now trying to work out what the mason, the bar bender and the plumber will actually build from, the honest answer is that the sanctioned plan is not that document, and the set you need next is the working drawing set, usually called the GFC set because every sheet in it is stamped good for construction. The sanction drawing exists to show Bidhannagar Municipal Corporation that what you are proposing sits inside what is permitted on that plot, so it carries the plan, the sections, the elevation and the area statement, and there its job ends. The GFC set exists for a different reason, which is to take decisions away from the site, so it carries dimensions to the face of masonry, beam and column positions with a structural consultant's numbers behind them, slab and sunk levels, pipe routes, switch heights, door swings and the shutter sizes a carpenter will cut to.

Salt Lake makes all of this more consequential than it would be on an open site at the edge of the city. The sectors were laid out as a planned grid, so the plots are regular and the roads are generous, but the plots themselves are tight, and many of them sit beside neighbours who built up to the boundary decades ago, which means the light and the air your building gets has to come from inside your own plot rather than from a gap next door. The stock around you is mixed, with houses from the sixties through the nineties standing next to newer G+3 and G+4 rebuilds, so the party condition on one side may be a single storey wall and on the other a four storey one, and those two facts move your foundation drawing and your waterproofing details before anybody has drawn a line of the facade.

So this page sets out what a working drawing set contains, the order we prepare it in, how it gets coordinated, and what it costs you when it is thin. Studio Contour has worked on this belt since 2014, with 330+ buildings delivered, and the drawings are prepared in house by the same team that runs the sanction, so what follows is the set we issue rather than a general description of good practice.

What a GFC set actually contains

A working drawing set is basically the complete instruction manual for a building, organised so that whoever is holding a single sheet on site does not have to interpret anything. The architectural sheets open with a setting out plan that locates the building on the plot from fixed references on the ground, which matters a great deal here, because a building set out even a few inches off on a tight plot can eat the side open space you were depending on for a bathroom window. After that come the floor plans dimensioned to masonry faces rather than to centre lines, the door and window schedule with lintel levels, the staircase drawing worked out against the actual floor to floor height instead of a nominal one, the toilet and kitchen layouts with fixture centres fixed, the chajja and terrace slope drawing, and the facade details that tell a mason where a projection starts and where it stops. The structural sheets carry the footing layout, the column schedule, the beam layout floor by floor and the slab reinforcement, all in reinforced concrete terms a bar bender can read with a tape and a bending schedule. The services sheets carry the plumbing riser, the drainage layout out to the municipal connection, tank positions, the electrical point layout set against furniture rather than against bare walls, and the air conditioning routes that have to be chased before plaster goes on.

Why a sanctioned plan is not a buildable plan

The sanction drawing is an abstraction on purpose, so wall thicknesses are nominal, services are absent, levels are mostly implied, and the layout is tuned to demonstrate compliance rather than to be built. The catch here is that a lot of people treat the sanctioned plan as the finished design, hand it to a contractor, and then discover on site that a beam sits where the wardrobe was going, that the toilet needs a sunk slab nobody allowed for, and that the staircase headroom is short by the thickness of a landing. None of that is the contractor's invention, it is simply the gap between a drawing meant for approval and a drawing meant for construction. We run the two as one process rather than two, so the submission is made from a design already resolved far enough to be built, and the GFC set then develops out of the same drawings instead of being reverse engineered from a stamped print. The sanction route itself we have written up separately, in one guide on Bidhannagar Municipal Corporation Building Plan Sanction for a G+2 Residential Building in Salt Lake and another on Bidhannagar Municipal Corporation Building Plan Sanction for a Rental-Income Apartment Block in Salt Lake, and both describe the sequence and the documents rather than promising an outcome, because the outcome depends on your plot.

The plot gets read before the sheets get drawn

Before any sheet is issued, somebody has to stand on the plot with a tape and a level. What we are looking for is the set of conditions that will quietly govern the drawings, so that means the actual plot dimensions against the deed, the height and condition of the walls next door and whether they are load bearing, the invert level of the municipal drain the house will discharge into, the turning space a transit mixer will need, the position of the existing electrical pole and water connection, and the levels across the plot, because plinth height against road level is not a thing you want to settle by eye on reclaimed ground. Those readings then go into the drawings as fixed constraints. A plot with a four storey neighbour on the south, for instance, will get its openings arranged so that cross ventilation comes off the free side and the light shaft, and the structural grid will be set to make that arrangement possible rather than fighting it. Frond House project in Salt Lake is an example of that category of work, a Salt Lake house where plan and structure were resolved together on a constrained plot.

Structure, services and finishes have to agree on paper

Coordination is where a working drawing set either earns its money or does not. The structural layout and the architectural layout have to be checked against each other sheet by sheet, so that beams land on walls rather than across rooms, columns do not appear in the middle of a door, and the depth of a beam over a window is reconciled with the curtain track and the false ceiling before anything is cast. Plumbing has to be reconciled with structure as well, because a sunk slab for a toilet, a trap position, a shaft for a riser and a slope for a terrace outlet are all structural decisions as much as plumbing ones. Electrical points have to be reconciled with the furniture layout, since a socket behind a fixed sideboard is a socket you have paid for and cannot use. Waterproofing at the terrace, the chajjas, the parapet junction and the external wall base has to be drawn and not described, because a Kolkata monsoon finds every junction that was left to the site to figure out, and the long humid stretch either side of it finds the rest.

The order we work in, and where the set is frozen

The sequence matters more than the number of sheets, because a set issued before the design decisions are closed will be revised on site, and site revisions are the expensive kind.

We freeze the architectural set before excavation begins, the structural set before steel is ordered, and the services set before the first slab is cast, since each of those is the last cheap moment at which a change can be absorbed. Finishes and joinery are deliberately allowed to stay open longer, because a tile selection or a shutter finish can be settled during shell work without costing anything, which is how you keep flexibility where it is free rather than where it is expensive. The whole set is checked by the principal architect before release, and Sumana Kumar stays on the project through sanction and through site rather than handing it to somebody else once the agreement is signed, which is the only reason a frozen set stays meaningful when the site calls with a question at eight in the morning.

Every option arrives with its cost attached

Budgets on a build rarely drift because of one large error, they drift because of a long sequence of small upgrades that were each agreed in isolation and never added up. So every option we put in front of you carries its cost consequence next to it, whether that is a change in the slab arrangement, a shift from a brick parapet to a railing, an extra toilet on the first floor, or a wider window that needs a deeper lintel. When you change your mind the budget moves with the decision in the same conversation, which is the only way a client actually steers the cost of a building instead of being told at the end what it became.

Interior working drawings sit on the same set

Architecture and interiors are usually split between two vendors, and the split is where information gets lost, because the carpenter's drawing and the structural drawing were never checked against each other. We keep residential architecture and residential interior design with one team for exactly that reason. In practice it means the electrical layout is drawn against the wardrobe internals rather than against an empty wall, the false ceiling is drawn against the beam depths that already exist, the kitchen services are set out before the slab is cast rather than chased into it afterwards, and the joinery sheets carry the same dimensions the shell was actually built to. We have written separately about Open-Plan Living and Dining Design for Salt Lake Flats, about Crockery Unit Design for Salt Lake Dining and Kitchen Spaces and about Walk-In Wardrobe Design for Salt Lake Homes, and all three assume the shell drawings and the joinery drawings came out of the same set. Residential Building Project in Salt Lake is an example of that category of work, and the same approach runs through our interior design across Salt Lake.

When a different kind of provider suits you better

There are cases where a full working drawing set is not the right spend. If you are doing a cosmetic refresh of a flat, repainting, swapping a few shutters and changing light fittings, a good contractor and a furniture brand will finish it faster and cheaper than a design process will, and there is very little to coordinate. If the shell is already built and all you need is sheets drawn up from measurements you already have, a drafting service will do that at a fraction of what a studio charges, and that is a reasonable choice. If your decision criterion is the lowest quote, you will not be happy with us, because our drawings add cost at the start in order to remove cost later, and that trade only pays if you value the later part.

Whoever you end up hiring, these four are worth settling in writing before any money moves.

Where to start on your own plot

If you are buying or have just bought a plot, the useful first step is a plot study and a brief, because that is what tells you whether the building you have in mind fits what the plot allows, and it costs very little next to discovering the answer after excavation. Anything to do with title, the tax treatment of the construction or your loan structure should go to your own lawyer, chartered accountant or lender, since those are their decisions to advise on and not ours. For the building work itself you can see the range of what we do on our Salt Lake area page, and when you are ready to talk about your plot, get in touch.