If you run an interior or architecture studio in India, one question shows up on every proposal, and it never really goes away: how do I actually charge for this?
Flat fee. Per square foot. Percentage of project cost. You've probably tried all three at some point, maybe on the same client, and felt that little knot in your stomach when you hit "send" on the number. Am I leaving money on the table? Am I too expensive? Will they compare me to the guy down the road quoting half of this?
I've watched a lot of studios wrestle with this. So let me lay out the three models plainly, with real rupee examples, and tell you what I'd actually use for which kind of project. No theory. Just what holds up on site and at month-end.
The three ways Indian studios charge
1. Flat design fee (lump sum)
You quote one number for the whole design scope. "₹3,50,000 for the full 3BHK, including concept, drawings, 3D views, and site coordination." Clean. The client knows exactly what they're paying.
This is the model most residential clients understand instantly. They're not builders. They don't want a running meter. They want a price, a scope, and a signature.
The problem is scope creep. You quoted for a 3BHK design. Now they want the terrace, the pooja room redone, three revisions on the master bedroom, and "just one small thing" for the mother-in-law's room. Your flat fee doesn't move. Your hours do. And your margin quietly bleeds out.
Flat fee works beautifully when your scope is tight and written down. It falls apart when it's vague.
2. Per square foot
You charge a rate per built-up or carpet area. "₹150 per sq ft for design." A 1,200 sq ft flat becomes ₹1,80,000. Simple maths the client can verify.
Rates in India vary wildly by city and positioning. I've seen ₹50 per sq ft from someone hungry for work, and ₹400+ per sq ft from an established studio in a metro doing high-end residential. The number itself tells the client a lot about where you sit.
Per sq ft is honest and easy to compare, which is exactly its weakness. It invites price shopping. And it doesn't reflect effort. A 1,500 sq ft minimalist apartment might be far less work than a 900 sq ft home where the client wants five moodboards, custom joinery in every room, and a heritage-look bathroom. Same area, wildly different effort, same fee. That's a margin trap.
Per sq ft also breaks down on commercial, retail, and F&B, where the design intensity per foot is completely different from a home.
3. Percentage of project cost
You charge a percentage of the total execution budget, usually somewhere between 8% and 15% for interiors, sometimes lower for large-value architecture projects. If the fit-out costs ₹40 lakh and you charge 10%, your fee is ₹4 lakh.
This is the model architects have used forever, and it has real logic: bigger, costlier projects genuinely need more of your time, more drawings, more coordination, more site visits. Your fee scales with the complexity.
But percentage-of-cost has a dirty little conflict baked in, and clients know it. If your fee goes up when the project costs more, why would you ever push the client toward cheaper materials or a tighter budget? A sharp client will ask you this to your face. You need a clean answer, and ideally a structure that removes the doubt (percentage fixed at the sanctioned budget, not the final bill; or a capped fee).
Percentage also means you often don't know your own fee until the BOQ is close to final. Awkward when the client wants a number today.
So which one should you use?
Here's how I'd actually decide, and most good studios end up doing a mix.
- Small, well-defined residential (single room, a kitchen, a quick refresh): flat fee. Nobody wants a percentage calculation on a ₹2 lakh job.
- Full-home residential where scope is clear: flat fee, with revisions and add-ons priced separately and stated up front.
- Full-home where the client is still figuring out how big they'll go: per sq ft, or percentage, so your fee scales as their ambition grows.
- Larger residential, villas, and premium projects: percentage of cost, capped, so you're paid for genuine complexity.
- Commercial, retail, F&B, offices: usually percentage or a custom lump sum, because per sq ft undersells design-heavy commercial work.
- Architecture and turnkey: percentage of construction cost is still the norm and the client expects it.
The real answer isn't "pick one." It's "know your cost per project first, then pick the model that protects it." If you haven't nailed down what a project actually costs you to deliver, no pricing model will save you. I wrote a full breakdown of that in How to Price Interior Projects in ₹ (Fees, Markups, Margin), start there if your fees feel like guesswork.
The hybrid most Indian studios settle on
After enough projects, most studios I've seen land on some version of this:
A fixed design fee for the core scope (so the client gets a clear number), plus a percentage or per-item markup on execution and procurement (so you're paid for running the actual site). This gives you a predictable design fee AND upside on the money that flows through your hands during execution.
The execution markup is where the real money often is, and where the leaks are worst. You buy the plywood, the veneer, the hardware, the lights, the sanitaryware, and if you're not tracking every PO against every quote, margin walks out the door in ones and twos. This is exactly the gap I keep hammering on in How to Protect Your Margin on Every Design Project. Your pricing model can be perfect on paper and still lose money if procurement is a WhatsApp mess.
GST, and the part everyone forgets
Whatever model you pick, quote clearly. Interior design services in India attract GST (18% on design services at the time of writing, confirm current rates with your CA, they do change). Your ₹3,50,000 design fee is ₹4,13,000 to the client with GST. If you don't say "+ GST" on your proposal, you'll either eat it or have an ugly conversation later.
A few practical habits that save headaches:
- Always write "+ GST" next to the fee. Never quote a fluffy round number that hides it.
- Split design fee and execution clearly on paper, the tax treatment and the client's expectations differ.
- Take milestone advances (typically 40-50% to start), and raise a proper GST invoice against each. Don't run a lakhs-worth project on verbal promises and screenshots.
- Reconcile what you invoiced against what you actually collected. Every month. This is where studios quietly lose track of who owes them what.
Collecting cleanly matters as much as pricing cleanly. A great fee you never fully collect is just a story you tell yourself.
The number is a positioning decision, not just a calculation
Here's the thing nobody tells you early on: your pricing model signals what kind of studio you are. Per sq ft at a low rate says "affordable, high volume." A confident flat fee or a healthy percentage says "premium, selective, worth it." Clients read this instantly.
If you're stuck competing on per sq ft against people who'll always go lower, the fix usually isn't a cleverer formula, it's moving up. Better clients, better projects, and the confidence to charge for the value you actually deliver. That's a whole shift in how you sell, and I got into it in How to Win Premium Interior Clients (and Charge More) and How to Raise Your Design Prices Without Losing Clients. Worth reading if your rates have been frozen for two years while your rent and your team's salaries haven't.
And if you want your revenue to stop being a rollercoaster of one-off projects, look at layering in retainers and recurring revenue, maintenance contracts, ongoing consultation, staged rollouts for commercial clients. A predictable base under your project income changes how you sleep at night.
Where Designa fits
None of this works if your quotes, invoices, and procurement live in six different places. That's the actual problem, not the pricing model, but the mess around it.
Designa is built for exactly this. You spec a project room by room, turn that into a quote the client approves online, and convert the approved quote straight into a GST invoice, no re-typing, no version-mismatch between what you quoted and what you billed. Whether you charge flat, per sq ft, or percentage, the number flows cleanly from proposal to invoice to Razorpay collection, and syncs to Tally or Zoho Books so your accountant isn't chasing you. Your purchase orders and deliveries sit in the same place, so execution margin stops leaking. One workspace for the whole studio, up to 10 members, unlimited free client logins.
Pick the pricing model that fits the project. Just make sure the tool underneath keeps every rupee of it accounted for.
See the founding offer at https://go.designa.work, ₹2,299 + GST per year for the whole studio, 7-day money-back, and done-for-you onboarding so your existing projects come across without you lifting a finger. Or poke around the live demo first at https://demo.designa.work and see how a quote becomes a GST invoice in two clicks.