Yes, I can take a hand sketch to a 3D render, and I do it several times a year. But a sketch carries maybe a third of the information a render needs. The rest gets guessed, and the only real question is who does the guessing: you, in a ten-minute reply to my questions, or me, silently, in the model.
The second way is how people end up paying for the wrong room.
What a sketch tells me, and it's more than you'd think
A decent sketch is good at intent. I can see where the sofa faces, that the island runs parallel to the window wall, that you want a low pendant over the table and tall storage on the left. I can usually read the mood too, because people draw the things they care about with more lines. The kitchen someone has thought about for six months has handles and a tap on it. The corner they haven't decided has a plant.
That's all useful. Composition, layout logic, what the hero of the image is: a sketch often says those more clearly than a Revit export does.
What it doesn't hold is size.
The five things that get guessed
Every sketch-only brief leaves the same gaps. In rough order of how much trouble they cause:
- Room dimensions. A sketch has proportions, not metres. Whether the room is 3.4 m or 4.6 m wide changes whether that island fits at all.
- Ceiling height. If nobody says, I assume 2.6 to 2.7 m for a new-build flat. An old town apartment at 3.2 m is a different picture entirely.
- Openings. Window width, sill height, head height, door positions. Sketched windows are nearly always drawn bigger than the real ones.
- Furniture sizes. I fall back on standards: 600 mm deep worktops at 900 mm high, a 2.2 m three-seat sofa, 750 mm table height. Your custom piece may not be standard.
- Materials and light. "Wood floor" covers everything from pale ash to smoked oak, and a sketch never says which way the room faces.
None of these is hard to answer. They're just invisible on paper, so nobody thinks to mention them.
Sketch perspective lies, and a camera can't
This one catches people out, so it gets its own section. When you draw a room by hand you unconsciously show three walls, the whole floor, the ceiling detail and the view through the window, all at a comfortable size. A real camera standing in that room can't do that. To see as much as the sketch shows I'd need something like a 12 mm lens, and at 12 mm the near furniture stretches, verticals lean and the room looks twice its length. I normally shoot interiors between 18 and 24 mm for exactly that reason.
So the render will never match the sketch line for line. It can match the idea: same viewpoint, same hero, same balance. But something drops out of frame, usually part of a side wall or the ceiling, and it's better you hear that from me before the first preview than discover it in the image. If the sketch really does need everything in it, the honest answer is two camera angles, not one distorted one. I went through how I pick them in the piece on camera angles.
A kitchen island that didn't fit
Last winter an interior designer sent me a biro sketch on the back of a supplier quote. Open kitchen, island with three stools, dining table beyond. Lovely drawing. No dimensions, but she mentioned the flat was about 60 m², so I blocked the room out at what the proportions suggested and placed the island as drawn.
It looked right. Then her answer to my standard questions came back with one number on it: the kitchen zone was 3.4 m wide, wall to wall. The island as sketched would have left 550 mm of walkway on each side, which nobody can cook in. We shortened the island, lost a stool, turned the table 90 degrees, and the final image was a room that could be built.
Total cost of that correction: about twenty minutes, because it happened in grey blocks before any materials existed. Had I guessed and gone straight to a finished render, it would've been a rebuild.
The seven answers that replace a drawing set
I don't need CAD. What I need with a sketch is short enough to type on a phone:
- One overall room dimension, length or width, in metres. A single real number lets me scale everything else.
- Ceiling height.
- Window and door sizes, or a phone photo of the wall with them in it.
- Which way the main window faces, or simply "morning sun" or "evening sun".
- Three reference photos for materials: floor, main joinery, one for overall mood.
- Any piece that's fixed (the sofa you already own, a specific pendant, a product link).
- What the image is for: client approval, a sales listing, a planning chat with a builder.
Photograph the sketch flat, square on, in daylight. A scan is better (most phone scanner apps flatten the page for you). A photo taken at an angle across a desk bends the proportions I'm trying to read, and those proportions are the one thing the sketch is giving me.
If there's an existing room, six phone photos from the corners beat any description. If there's an estate agent's floor plan, send that as well, even a rough one, because a floor plan plus a sketch covers most of what a proper drawing set would.
Grey first, colour later
With a sketch brief I always send an untextured block-out of the room before anything pretty happens. Plain grey walls, boxes for furniture, the camera roughly placed. It takes me a couple of hours and it's ugly on purpose.
Why bother? Because that's the moment every guess becomes visible. You look at it and say the window's too wide, the ceiling's too low, the wardrobe should stop short of the door. Moving a wall at this stage takes minutes. Moving it after materials, lighting and a 4000 px final is most of a day, and it eats one of the two consolidated revision rounds that come with every render. I'd rather those rounds went on things you can only judge in the finished image, like the tone of the oak or how warm the evening light is.
Does a sketch brief cost more?
Not automatically. The published rate is the same whatever the input: an interior render starts from EUR 250 per camera angle, exteriors from EUR 450, with a EUR 200 minimum order and 10% off the render subtotal once three renders are combined. Three views of one apartment come to EUR 675 on that basis. The full table is on the architectural rendering prices page.
Where a sketch can move the number is modelling. A room with custom joinery that exists only as pencil lines takes longer to build than the same room exported from SketchUp, and if that's the case I say so in the quote, in writing, before any work starts. Timing shifts in the same way. The target of a first preview within 3 business days counts from a complete brief, and for a sketch, complete means the seven answers above have arrived.
Is it still cheaper than commissioning measured drawings just to get a render? Almost always.
What I'd actually do with a sketch and a deadline
Send the sketch today, as it is. Don't redraw it neatly, don't wait until the dimensions are perfect. Add the one room measurement and the ceiling height, and three reference photos. That's enough for me to give a fixed quote and start the grey block-out.
The mistake I see most is the opposite: people hold the sketch back for two weeks while they try to turn it into a "proper" plan, and what arrives is a tidier drawing with the same missing numbers.
A second point, and it's one people don't expect. Tell me which parts of the sketch are decided and which are open. If the kitchen is fixed and the living area is still up in the air, I'll put the modelling hours into the kitchen and keep the rest calm and neutral. A sketch treats every line as equally certain. You know better.
You can see finished rooms that began as rough input in the portfolio, and what's included for interiors on the interior rendering services page. When you're ready, upload the sketch through the quote form and I'll reply with a non-binding quote and my list of guesses for you to correct.