Interior Designer vs. Architect vs. Project Manager: Who Do You Actually Need for a Renovation?
Interior Designer vs. Architect vs. Project Manager: Who Do You Actually Need for a Renovation?
Quick answer: If your renovation stays within your existing footprint or extends outward at ground level, an interior designer can usually manage the design and consent process. If you're building upward (adding a second storey), you'll need an architect. A project manager comes in after the design is locked in, to get competitive quotes and run the build. Going straight to a builder before the design is finalised is the most common, and most costly, renovation mistake homeowners make.
Renovating a home involves more decisions about who to hire than most people expect. The default assumption is often "I need an architect," but for a huge number of renovation projects, that's not actually true, and it can mean paying for expertise you don't need. Here's how the three roles actually differ, and how to work out which one (or which combination) your project calls for.
| Interior Designer | Architect | Project Manager | |
|---|---|---|---|
| Best for | Interior renovations, ground-floor extensions, kitchens, bathrooms, layout changes | New builds, second-storey additions, architecturally designed homes | Managing the build phase once design is finalised |
| Handles consent | Yes, for straightforward renovation consents | Yes, including complex resource and building consents | No, works from an already-consented design |
| When to bring in | Early, at the start of planning | Early, before any design work begins, if extending upward | After design and consent, before construction |
| Structural or watertightness issues | Refers out to a draftsman or engineer | Handles directly, or works with an engineer | Coordinates trades but doesn't design solutions |
| Where they sit in the process | First | First (if extending up) | Middle, after design, before building |
Interior Designer: The Overlooked Option for Renovations
This is the one homeowners most often skip past, usually because they assume "renovation" automatically means "architect." In practice, an interior designer is frequently the right first call, especially when:
The renovation is internal (kitchens, bathrooms, layout reconfiguration, flow)
The extension goes outward at ground level, rather than up
You need someone to manage straightforward renovation consent documentation
A good interior designer can take a renovation from concept through to a consentable design without an architect ever needing to be involved. Where it gets more complex, anything touching on watertightness or structural work, the right move isn't to escalate to an architect by default, but to bring in a draftsman (or structural engineer, depending on the issue) for that specific piece, while the interior designer continues to manage the overall design.
Architect: For Going Up, or Going Bespoke
An architect becomes the right call in two main scenarios:
You're extending upward. Adding a second storey (or any vertical addition) introduces structural and consent complexity that sits squarely in architect territory.
You want an architecturally designed home. If the goal is a fully bespoke design, not a renovation of an existing layout but a from-the-ground-up architectural vision, that's an architect-led project from day one.
Architects are essential for these projects. The issue isn't that architects are overused, it's that they're often engaged by default for renovation work that doesn't actually need that level of service, when the budget could be better spent elsewhere, like a more detailed interior fit-out, or the build itself.
Interior Designer and Architect, Working Together
These two roles aren't mutually exclusive. On architect-led projects, an interior designer often comes on board to handle the finishes and fittings: cabinetry, benchtops, tapware, lighting, flooring, paint colours and the overall feel of each room. The architect shapes the structure and the shell of the home, while the interior designer makes sure everything inside it works together and reflects how you actually want to live. Bringing an interior designer in alongside your architect, rather than leaving those decisions until the end, usually means a more considered result and fewer costly changes of mind mid-build.
Project Manager: Brought In After the Design, Not Before
This is where the sequencing of a renovation trips people up most. A project manager's real value shows up once the design is complete: they can go to the market with a finished plan and get multiple builders to quote against the same brief, which is how you get comparable, competitive pricing.
The mistake many homeowners make is going to a builder first, before design work has even started. It feels efficient, get a number, get moving, but it usually means:
Pricing a moving target, since the design isn't locked in yet
Losing the ability to compare quotes properly, since there's nothing fixed to compare them against
Design decisions being shaped by construction convenience rather than what actually works for the home
The builder should be one of the last people you bring in, not the first. Design, then documentation, then quotes, then build, in that order.
The Right Order for a Renovation
Interior designer (or architect, if extending up or going fully bespoke), design and consent
Draftsman or structural engineer, only if watertightness or structural issues come up
Project manager, once design is finalised, to secure and compare quotes
Builder, brought in last, once there's a clear, priced, consented plan to build to
FAQ
Do I need an architect for a renovation? Not necessarily. If your renovation is internal or extends outward at ground level, an interior designer can typically manage the design and consent process. Architects are generally needed when a renovation extends upward or when the project is a fully architecturally designed build.
Can an interior designer get building consent? Yes, for straightforward renovation projects. More complex consent issues involving structural work or watertightness are usually referred to a draftsman or engineer.
Can an interior designer work alongside an architect? Yes. It's common for an interior designer to handle finishes and fittings, cabinetry, tapware, lighting, flooring and colour, on a project the architect is leading, so the interior feels as considered as the architecture itself.
When should I bring in a project manager? After your design is finalised, not before. A project manager's main value is running the quoting process against a completed design and managing the build.
Should I talk to a builder before I have a design? It's best not to. Getting a design finalised first means you can get comparable quotes from multiple builders, rather than pricing a project that's still changing shape.
What's the difference between a draftsman and an architect? A draftsman typically handles technical drawings and consent documentation for specific issues like structural or watertightness details, working alongside an interior designer. An architect leads the design itself, particularly for upward extensions or architecturally designed homes.
Not sure which path fits your renovation? We can talk through your project and let you know honestly whether you need an interior designer, an architect, or a bit of both.
-Laura Heynike
