Column-Free Spans in a Salt Lake Home and What They Cost

Column-Free Spans in a Salt Lake Home and What They Cost

If you are building on a plot in one of the Salt Lake sectors and somebody has shown you a plan where the drawing room runs clear from one side wall to the other with nothing standing in the middle of it, you already know why the idea is attractive, and you have probably also noticed that nobody will tell you plainly what it adds to the bill. A column-free span costs you in three separate currencies, money in the frame, height in the ceiling, and flexibility in the floors above, and those three do not move together, so a span that looks cheap in one of them is quietly expensive in another.

This page is written for the stage you are probably at right now, which is after the plot is yours and before the structural scheme is frozen, because that is the only window where this decision is still free. Once the columns are cast you are living with that grid for the life of the building, and the open hall you wanted stops being a design choice and becomes an expensive retrofit. So what follows is how we work the question on an actual Salt Lake plot, where the span wants to go, where the column wants to go, what each route does to the number, and what we would tell you to spend the money on instead if the span is not earning it.

We are Studio Contour, an architecture and interior design studio working from New Town across the Salt Lake, New Town and Rajarhat belt, founded in 2014, with 330+ buildings delivered. Sumana Kumar is the principal architect, and she stays with the drawing through sanction and through site, which matters more on this question than on almost any other, because a long span is decided during structural coordination and then has to be defended every week on site once the bar bending starts.

What a column-free span actually is, and what the building pays for it

Basically a span is the distance a beam or a slab has to cross between two supports, and when you ask for a room with no column in it you are asking that distance to grow. The load does not disappear when the column does, it simply has to travel further before it finds something to stand on. In a reinforced concrete frame, which is how almost every house in these blocks is built, a longer span means a deeper beam or a thicker slab, more steel in the bottom of that beam, larger columns carrying the heavier beam down, and larger footings under those columns, right down into the soil. The catch here is that none of this shows up as a single line you can argue about in an estimate, it is distributed through the whole frame, which is precisely why a contractor quoting you a rate per square foot has no reason to separate it out and show you what the open room is costing.

The ceiling height you give up, which is the cost nobody quotes

That deeper beam has to sit somewhere, and in a conventional frame it hangs below the slab, so the underside of the beam becomes the real ceiling line at the edges of your open room. Then you run the air conditioning piping and the wiring under it, you add a false ceiling to hide all of that, and the generous hall on the plan ends up with a much heavier edge than you imagined when you looked at the drawing. You can answer that by raising the floor-to-floor height, but that spends your overall height allowance, which varies by plot and sector and has to be confirmed for your specific plot before anybody promises you another floor on top. If you have already lived with the result of this somewhere, our piece on Sitting Room Design When the Ceiling Is Low and the Window Is Single is the same problem seen from the inside of a finished room.

Why a Salt Lake plot makes this a sharper question than it looks

Salt Lake is a planned grid of blocks and sectors with a lot of building stock from the sixties through the nineties, and the plots are regular, which sounds helpful until you notice how tight they are. Your neighbours on both sides have very often already built right up to the boundary, so every bit of light and air your house gets has to come off your own plot, through your own front, rear and whatever side strip you have left. That puts the column grid in direct competition with your openings, because the places where a column is structurally convenient are frequently the same places where you wanted a window, a light well or an open corner. Newer G+3 and G+4 rebuilds now sit beside much older houses on the same stretch, so the house next door is no guide at all to what your frame should do, and the staircase makes it worse again, as we set out in Staircase Design in a Salt Lake House: The Decision That Eats Width.

Parking usually decides the grid before the drawing room does

On most of these plots the ground floor is carrying parking, and cars are unforgiving about column positions in a way that furniture is not. A column that lands a little way into the front bay can cost you a car, and once you have moved it to clear the parking, that position wants to repeat on every floor above, because a column that jumps around between floors needs a transfer beam and that is a far more expensive conversation. So the honest sequence on a Salt Lake plot is that parking sets the grid, the grid then offers you a set of possible open rooms upstairs, and the column-free span you actually get is the one that survives both.

The three ways to buy the span, and what each one does to your budget

There is more than one way to buy the same open room, and the choice is really a decision about where you want the cost to land, in the concrete, in the ceiling line, or in the coordination between trades on site.

Monsoon, humidity and the second bill a long span can send you

A long span deflects more than a short one, and that is not a defect, it is arithmetic, but it has consequences you meet later rather than at handover. Partition walls sitting under or beside a long span are the first place you see it, usually as a hairline running along the junction of the wall and the ceiling, and a long stretch of humid weather followed by a serious monsoon is very good at finding that line and making it visible. On the roof the same span carries the terrace, so the fall, the drainage outlets and the waterproofing detail all have to be worked out for a plate that moves slightly, right where it is widest. None of this argues against the open room, it argues for the span being designed rather than assumed, with the partition layout and the terrace drainage settled at the same time as the beam sizes.

How we put a number against each option instead of an adjective

For instance, on a typical G+2 or G+3 here we will show you the frame two or three ways, the open hall with the heavier beam, the slightly shorter hall with a flat ceiling, and the version where a column stays and the room is planned around it, each one with its cost consequence attached, so your budget moves as you decide rather than after you have decided. Seeing it helps more than reading it, which is why we take the chosen option into 3D visualisation of the building before it is built, and the reasoning behind doing that at this stage is set out in 3D Elevation Visualisation Before You Build in Salt Lake. The reason the beam position matters so much is that it governs the furniture and the lighting that follow, so our residential interior design work is coordinated against the same structural drawing instead of discovering the beam after the slab is up, and that single-team approach runs through our interior design across Salt Lake projects as well. Frond House project in Salt Lake is an example of that category of work.

Drawings, structure and the Bidhannagar sanction route

The structural question and the sanction question are the same question on these plots, because the grid you settle has to be consistent with the plan you submit, and amending a sanctioned drawing later costs you time you did not budget. We prepare the drawing set and run it through the Bidhannagar Municipal Corporation sanction process ourselves, so the column grid, the parking layout and the plan the authority sees are one document rather than three. The statutory numbers that shape all of this, the coverage, the setbacks and the height you are allowed, vary by plot and must be confirmed for your specific plot rather than taken from a neighbour's house, and the two guides worth reading alongside this one are Bidhannagar Municipal Corporation Building Plan Sanction for a Duplex on an Individual Plot in Salt Lake for the submission itself and Occupancy Certificate Under Bidhannagar Municipal Corporation in Salt Lake: A Plot Owner's Guide for what happens at the far end of the project.

What to ask before you pay for the span

Whoever you end up appointing for the work, these are the four answers that tell you whether the span in front of you has actually been designed, or simply assumed and absorbed into a rate.

When a different kind of provider suits you better

If you are not touching the structure at all, if the slab and the columns are staying exactly where they are and the work is cabinetry, finishes and loose furniture in a flat you already own, then a good fit-out contractor or a furniture brand with a design desk will get you there for less than we will, and you should use one. If your plot is regular, your brief is a conventional G+2 with ordinary room sizes and no open span worth arguing about, and your constraint is the lowest possible fee, a competent drafting service with a structural consultant attached will produce a sanctionable set. We are the right call when the plot is awkward, when the span, the parking and the light are fighting each other, or when you want one party answerable for the whole thing from the grid to the switch plates.

Where to take this next

If you are weighing an open hall against a column and you want the two versions costed rather than described, bring us the plot papers and whatever you have of the survey, and we will test the grid before anything is committed. Our Salt Lake area page covers the rest of what we do in these sectors, Cypress House project in New Town is another example of this category of work, and you can get in touch to put your plot in front of the drawing board.