Architect vs Interior Designer: Who to Hire for Your Project

Planning a new build, extension, or major renovation can feel confusing if you are unsure which professional to hire first. Many UK homeowners wonder whether they need an architect, an interior designer, or both. Each role brings distinct skills, training, and responsibilities. Understanding how architects and interior designers differ will help you create a home that is safe, practical, and visually appealing while keeping costs under control. This guide explains the qualifications, services, and project types best suited to each professional so you can make an informed choice and avoid unnecessary delays or expenses.

What Is an Architect?

An architect is a qualified design professional registered with the Architects Registration Board (ARB) in the UK. Most architects complete a minimum of seven years of university education and supervised training before earning this title. They focus on the structure and function of buildings, ensuring that every design meets planning permission requirements, building regulations, and safety standards. Architects also consider environmental impact, energy efficiency, and the long-term performance of materials. Whether you are planning a new house, a large extension, or a complex renovation, an architect provides the technical knowledge to bring your vision to life within legal and structural limits.

What Does an Architect Do Day to Day?

Architects handle every stage of a construction project. They create concept designs, prepare detailed technical drawings, and manage planning applications with the local council.

Their work includes spatial planning to make sure rooms flow well, coordinating with structural engineers and builders, and overseeing the build to ensure it matches the approved plans. They manage budgets and schedules, helping you avoid unexpected costs. From initial sketches to the final handover, an architect safeguards both design quality and structural integrity.

What Is an Interior Designer?

An interior designer focuses on how a space feels and functions once the building’s structure is in place. Interior designers often hold a university degree or diploma in interior design and may be members of professional bodies such as the British Institute of Interior Design (BIID).

Their expertise covers colour schemes, lighting plans, furniture selection, and the arrangement of interior elements to create a comfortable, visually balanced environment. They pay attention to textures, finishes, and how people will use each room in everyday life.

What Does an Interior Designer Do Day to Day?

Interior designers develop mood boards, source materials, and select furnishings that reflect a client’s taste and lifestyle. They plan lighting and furniture layouts, choose flooring and fabrics, and coordinate with suppliers and decorators to ensure everything fits seamlessly.

They also track budgets and timelines for decorating work. Interior designers excel at transforming interiors into spaces that are both practical and stylish, whether you are furnishing a new-build flat or updating an older property.

What Is an Interior Architect?

In the UK, the title interior architect is used for professionals who combine aspects of architecture and interior design. Unlike a registered architect, an interior architect is not legally required to register with the Architects Registration Board (ARB), but they usually have strong training in spatial planning and structural understanding, along with interior design skills.

This hybrid role focuses on adapting internal layouts moving walls, reconfiguring spaces, and improving circulation while also considering finishes and furnishings. An interior architect is valuable for projects where the building’s structure needs partial alteration alongside a fresh interior scheme, such as converting a warehouse into a loft-style home or reworking a large office into modern flats.

Architect vs Interior Designer: Key Differences Explained

Architects handle the building’s structure, from planning permission to safe construction. Interior designers concentrate on finishes, furniture, and how the space feels and functions. Understanding this split helps you decide who can best meet your project needs.

Education and Professional Credentials

An architect in the UK typically completes seven years of formal study and supervised practice, passing ARB or RIBA requirements. This makes them legally responsible for the safety and structural compliance of their designs.

An interior designer may hold a degree or diploma in interior design and can choose to join professional bodies such as the BIID, but they are not required to meet statutory regulations. This distinction means architects carry legal duties for structural safety, while interior designers focus on appearance and day-to-day usability.

Scope of Design and Authority

Architects have authority over structural changes, planning permission, and building regulations. They determine room dimensions, structural supports, and exterior appearance. Interior designers focus on interior finishes, furniture, lighting plans, and colour schemes, ensuring the completed structure feels comfortable and visually appealing. The architect’s remit includes the entire building shell and its engineering; the interior designer shapes how you experience that space once built.

Budget and Project Scale

Architect fees often range from a percentage of the total build cost to fixed-price contracts, reflecting their involvement from concept through construction. Interior designers typically charge hourly rates or a design fee, which can vary depending on the size and complexity of the project. For a new build or extension, hiring an architect provides long-term value through structural planning and regulatory compliance. For refurbishments or decorative updates, an interior designer can create a striking result without structural expenses.

Deciding Whom to Hire

When You Need an Architect

Hire an architect for new builds, loft conversions, house extensions, or any structural alteration that requires planning approval or must meet UK building regulations. Architects are essential for projects involving load-bearing walls, significant changes to plumbing or electrical systems, or detailed coordination with builders and engineers.

When an Interior Designer Is the Right Fit

Choose an interior designer for non-structural projects, such as refreshing a kitchen or living room, improving lighting plans, or selecting furniture and finishes. They excel at enhancing comfort and style when the building layout remains the same.

Can They Work Together?

Many successful projects combine both skill sets. An architect ensures the structure is sound and efficient, while an interior designer refines the final look and feel. For example, a large house renovation may need an architect to plan structural changes and an interior designer to create harmonious colour schemes and furnishings. Collaboration brings design harmony and often reduces costs by preventing changes late in the build.

Choosing the Right Professional for Your Project

Match the expert to your goals and budget. Hire an architect for structural work or planning approval, and an interior designer for decorative updates. For projects needing both, consider a team like HPW Architecture that blends these skills seamlessly

Assessing Your Goals and Budget

Start by writing a clear brief: list your must-have features, preferred style, and total budget. Review portfolios to see how each professional handles projects similar to yours. Check credentials ARB registration for architects and BIID membership for interior designers and agree on a written contract outlining services, fees, and timelines.

How HPW Architecture Combines Design and Interior Expertise

HPW Architecture offers an integrated service that blends architectural planning with interior design. Our team provides planning guidance, creative layouts, and technical precision, helping homeowners and developers achieve seamless results from structural concept to final decor. Whether you need a full build or a sophisticated interior plan, HPW can manage every stage under one roof.

Summary

Architects and interior designers serve different but complementary roles. Architects manage structural design, planning permission, and building regulations, while interior designers focus on aesthetic and functional interiors. Your choice depends on whether you need construction expertise, interior styling, or both. For projects that require integrated planning and design, contact HPW Architecture to discuss how our combined architectural and interior services can bring your vision to life with efficiency and style.