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What is a design brief?
Lahav Meiri, licensed renovation contractor · Published 3 August 2026
A design brief is the document that tells your architect what the house has to do - who lives there, how they live, what it has to solve, what it can cost, and what the site allows. It comes before any drawing. And on most residential projects, the person expected to produce it is you.
Most of what's written about design briefs is written for architects and architecture students. This is written for the person who has to hand one over.
One thing worth knowing before you start: the last section isn't about the document at all. It's the part of it that nobody else can write.
What a design brief actually is
It's the answer to one question: what does this building need to be and do?
Not what it should look like. Not how many rooms. What it has to achieve, for the people who will live in it, within the money and the ground available.
A brief is not a floor plan, and it's not a wish list. A floor plan is a solution; the brief is the problem it's solving. A wish list is a set of wants with no order; a brief separates what's fixed from what's flexible, and says why.
It exists so that every decision later has something to answer to. When someone suggests something in month four and it feels wrong, the brief is what tells you whether it actually is.
A floor plan is a solution. The brief is the problem it's solving
Design brief, client brief, project brief, program
Four words for overlapping things, used inconsistently even within the profession. Here's the practical version.
Program is the American term, and the most precise. It's the functional content: what spaces are needed, what happens in them, how they relate to each other.
Project brief is the wider container - goals, budget, timeline, constraints, who decides what.
Design brief usually means the same document with the design intent included: how it should feel, how you want to live in it, what matters.
Client brief is the same thing named by who produces it.
For a house, you need one document. Call it whatever your architect calls it. What matters is that it answers what the house must do, what it can cost, what the site allows, and how you want to live in it.
Who writes it
The answers you'll find online contradict each other. Some say the client writes it. Some say the architect does. Some say it's collaborative. All three happen in practice, which is why the question stays confusing.
The contract is clearer than the internet.
Under the AIA's standard owner-architect agreement, the owner's responsibilities include bringing the program - what the building needs to be and do. If the architect develops it for you, that's an additional service, charged separately.
So the honest answer: you write it, and your architect refines it. They will help - a good one asks the questions that pull it out of you. But the raw material is yours, and if you arrive without it, either the first meetings go into producing it, or you pay for it as a separate service.
This is worth knowing before you're in the room, because most people discover it there.
What goes into one, for a house
Length is not the measure. A brief for a house can be two pages if the two pages are right.
Who lives here, and how
Names, ages, routines. Where people actually spend time, and what a normal week looks like.
What's wrong with where you live now
The single most useful section, and the easiest to write. Specific failures are more reliable than stated wants.
What the house has to do
Spaces, and what happens in them. Which ones need to be near each other, and which need to be far apart.
Must-have and nice-to-have, separated
Not one list. Two, with the boundary drawn deliberately.
The budget, as a project cost
Land, site work, fees, connections, finishes, contingency. Not just the build.
The site
What's known, what's assumed, what hasn't been checked.
What changes in the next ten years
Children, parents, work. The house outlasts the situation you're in now.
What you don't want
Often clearer than what you do, and it saves everyone time.
The part nobody can write for you
Everything in the last section can be gathered. Room counts, budgets, site data - a professional can help you assemble all of it.
One part can't be gathered, because it isn't information. It's what you'd only say if someone asked you the right question and then waited.
Why you want what you want.
"A bigger kitchen" is a request. "We both cook and keep colliding" is a brief. The second one can be designed from; the first one can only be guessed at.
'A bigger kitchen' is a request. 'We both cook and keep colliding' is a brief
What you've never put into words.
Most people have a clear sense of how they want to live and no practice describing it. That's not a failure - nobody rehearses this.
Where the two of you don't agree.
Not the arguments. The things that haven't come up yet, and will, usually at the worst moment.
What you'd be genuinely upset to lose.
Every project reaches a point where something goes. The brief that survives that moment is the one that ranked things in advance.
That's the part of the brief only you can write. Nestbrief works through it with you.
See how it works →The brief is yours to bring
You can hire someone to draw the house. You can hire someone to build it. The one thing you can't hand off is knowing what it's for - and that turns out to be the part that decides whether the rest goes well.
Nestbrief asks you those questions one at a time, at home, at your own pace. When you say you want a bigger kitchen, it asks what for. When you're not sure, it helps you think it through instead of moving on. Nothing to prepare, nothing to fill in - you just talk.
This is what comes out of it:
One conversation, and you arrive with the document you were meant to bring.
Common questions
- How long should a design brief be?
- For a house, two to five pages is normal. Usefulness matters, not length - a tight two pages beats twenty that nobody reads.
- Do I need a brief for a renovation, or only a new build?
- Both, and arguably more for a renovation. An existing building has constraints and a history, and the brief is where you record what stays, what goes, and why.
- Can my architect write it for me?
- Yes, and many will. Under standard agreements it's an additional service, charged separately - so ask what's included before you assume.
- What if my brief changes during the project?
- It will, and that's normal. A brief is a living document. What matters is that changes are deliberate and recorded, rather than drifting.