ARB vs RIBA — What Is the Difference?
These two acronyms appear constantly in architect profiles and often confuse homeowners. They are not the same thing, and understanding the difference helps you evaluate credentials properly.
ARB — Architects Registration Board
ARB is the statutory regulator of architects in the UK, established by the Architects Act 1997. Only individuals on the ARB register can legally call themselves an “architect.” Using the title without registration is a criminal offence.
ARB registration requires a degree, a year of practical experience, and the ARB Part 3 professional practice examination. It is the minimum qualification to call yourself an architect in the UK.
RIBA — Royal Institute of British Architects
RIBA is a voluntary professional membership body. Membership (RIBA Chartered Member) indicates that a practice or individual meets RIBA's standards of professional practice, has professional indemnity insurance, and undertakes continuing professional development.
RIBA membership is a positive signal but not a guarantee of quality. There are excellent ARB-only architects and mediocre RIBA-chartered practices. Use it as one data point, not the deciding factor.
Practical tip
Verify ARB registration at arb.org.uk/arb-register-of-architects. If someone uses the title “architect” and is not on the register, that is a serious concern. RIBA membership can be verified at architecture.com/find-an-architect.
Planning Drawings vs Construction Drawings
One of the most expensive mistakes in construction: a homeowner pays for planning drawings, gets planning approval, then discovers their contractor cannot build from those drawings because they lack the technical detail. Understanding what each drawing type covers — and what it does not — prevents this.
Feasibility Drawings
Rough design options to test whether your idea is achievable within your budget and plot. Usually produced at early design stage. Not suitable for planning or building control.
Planning Drawings
The drawings submitted to the Local Planning Authority (LPA). They show the proposed design to a level sufficient for the council to assess impact on neighbours, streetscene and heritage. They are not sufficient for a contractor to build from.
Building Regulations / Technical Drawings
Detailed drawings showing how the building will be constructed, including structural details, insulation specifications, drainage, ventilation, fire separation and compliance with building regulations. These are what a contractor prices and builds from.
Construction Issue / Tender Drawings
The full package issued to contractors for pricing and construction. Typically includes building regulations drawings, schedules of works, specification documents and sometimes a Bill of Quantities. This is the most comprehensive package — and the most expensive to produce.
Common and costly mistake
Many online and low-cost architectural services deliver only planning drawings. The homeowner gets planning approval, starts getting contractor quotes, and discovers no one can give a firm price because the technical detail does not exist yet. Always clarify exactly which drawing stages your fee includes before signing.
Architect Fee Structures — What to Expect
Architects charge in several different ways. None is inherently better or worse — but you need to understand what you are agreeing to and what the fee covers before you sign an appointment letter.
Percentage of construction cost
5–15% of build costPros: Fee scales with project complexity. Architect is incentivised to add value.
Cons: If costs increase, so do fees. Less predictable for budgeting.
Fixed lump sum
Agreed per stage or in totalPros: Cost certainty. Clear scope for each stage.
Cons: May not cover changes to brief or abortive work. Re-scoping can be contentious.
Hourly rate
£60–£200/hr depending on seniority and practice sizePros: You pay for what you use. Works well for small or undefined scopes.
Cons: Costs can escalate without clear oversight. Ask for an estimate of total hours.
Per-stage fee
Fixed price per RIBA stagePros: Combines predictability with flexibility. Easy to pause between stages.
Cons: Requires clear definition of what each stage includes and excludes.
For a standard loft conversion in Greater London, a realistic architectural fee covering planning and building regulations stages typically ranges from £3,500 to £8,000 depending on complexity and practice size. Be wary of services priced below £1,500 — at that level, something is almost always excluded.
Questions to Ask Before Hiring
A competent architect will answer these questions clearly and without defensiveness. Vague or evasive responses — particularly around what is and is not included in the fee — are informative in themselves.
Are you ARB-registered? Are you also RIBA-chartered?
Have you worked on projects similar to mine in type, scale and planning context?
Will you be working on my project personally or will it be passed to a junior?
What do your fees cover and what stages are included?
Do your drawings go to a level of detail sufficient for a contractor to build from?
Who manages the planning application — you or me?
Do you have experience working with principal contractors like RCB?
What happens if the planning application is refused?
Can you provide references from completed projects of similar scope?
What structural engineering, party wall or specialist consultants do I also need?
Warning Signs to Watch For
These are patterns worth treating as genuine red flags — not just minor style differences.
How Your Architect and Contractor Need to Work Together
The single biggest cause of construction project problems is a gap between what the architect drew and what the contractor expected to build. This usually happens when the drawings are not detailed enough for accurate contractor pricing, or when the architect and contractor have never worked together and use different assumptions.
The best outcome is when an architect produces a genuinely construction-ready package — detailed technical drawings, a full specification, a schedule of materials — and the contractor prices it with no ambiguity. Anything short of this creates room for contract disputes, variation orders and cost overruns.
- Ask your architect to produce a specification document alongside the drawings, not just drawings alone
- Involve your contractor early in the process so they can flag constructability issues before the package is finalised
- Ensure your architect is willing to respond to RFIs (requests for information) from the contractor during build
- Clarify who manages building control inspections — architect, contractor, or building owner
- Confirm whether the architect will carry out any site visits during construction, and if so, at what frequency and at whose cost