How Much Does an Architecture Firm Cost? 6 Powerful Facts

When planning a home extension, renovation, or new build, one of the first questions homeowners ask is: how much does an architecture firm cost? The cost of an architecture firm depends on the level of service provided, project complexity, and whether the architect or Technician is involved during construction.

The answer varies depending on your project’s complexity, the architect’s pricing model, and the level of service you need. In this 2025 guide, we break down architect fees in the UK, explain pricing structures, and reveal how regulations now impact your costs.

1. How much does an architecture firm cost?(UK 2025 Guide Based on RIBA Guidelines)

Architects in the UK typically use one of three pricing methods:

Percentage of Construction Costs

According to RIBA guidelines, architects charge 5% to 15% of your total construction cost:

• Basic design only (concept + planning): 5% – 8%
• Full architectural service (design, planning, technical working drawings, site oversight): 10% – 15%

Example: A £150,000 extension could attract architect fees of £7,500 – £22,500, depending on the level of service.

Fixed Fees

For specific tasks, architects may offer fixed prices:

• Planning drawings: £2,500 – £4,000
• Building Regulations drawings: £3,000 – £6,000

Hourly Rates

For smaller projects or consultations, fees typically range £75 – £200 per hour.

• Example: A two-hour consultation could cost £150 – £400.

Source: RIBA Guide to Architect Fees

2. Carter Designs’ Fair Time-Based Pricing Model (No Percentage Mark-Ups)

How much does an architecture firm cost? Unlike many firms, Carter Designs uses a transparent, time-based pricing model — so you only pay for the work done.

Our Rates:

£70 – £85 per hour (depending on project complexity)

No inflated percentage mark-ups
Tailored to your specific project needs
Full breakdown of time spent

Typical House Extension:
50 – 80 hours → £3,250 – £5,200 (realistic for a standard project)

See our House extension cost calculator for further guidance

Contact us for a free no obligation quotation

3. Architecture Costs for typical House Extensions in 2025 (UK)

The below are typical costs you may pay depending on which service level you require:

Important: Partial services may look cheaper upfront, but the 2023 Building Safety Act now makes on-site professional involvement essential.

Why working drawings are essential

4. How Much Does an Architecture Firm Cost? – for a New Build Home

How Much Does an Architecture Firm Cost? Designing a new home is complex — it’s about far more than producing drawings or pretty visuals. A common misconception is that architectural work focuses solely on creating plans or images. In reality, the drawing stage accounts for only 30-40% of the total work involved.

The majority of an architect’s time is spent co-ordinating with other consultants, researching materials and products, and ensuring full compliance with Building Regulations. Every detail, from structural design to fire safety and energy performance, must be carefully considered and integrated — often requiring dozens of hours behind the scenes to get right.

Typical Architect Fees (RIBA 2025 Guide):

• 7% – 15% of the total build cost depending on design complexity and level of involvement.

Example: For a £300,000 new build → Fees range from £21,000 – £45,000.

Carter Designs Time-Based New Build Costs:

How Much Does an Architecture Firm Cost? At Carter Designs our approach gives you full control and transparency:

3-4 bedroom new build: Expect £8,500 – £18,000 (depending on site conditions and complexity)

What’s Included:

• Concept design & feasibility studies
• Planning applications
• Detailed technical drawings for Building Regulations
• Site inspections & contract administration
• Principal Designer role (mandatory under the 2023 Building Safety Act)

Why It’s Worth It:

Ensures full compliance & avoids costly mistakes
Protects your build quality and budget
Adds long-term value and energy efficiency

5. 2023 Regulation Update – How the Building Safety Act Impacts Architect Fees

Since October 2023, the Building Safety Act now applies to all residential projects — not just high-rise.

Key Points for Homeowners:

You must appoint a qualified Principal Designer (often your architect or architectural technologist).
The role requires site inspections, not just paper drawings.
No Completion Certificate = non-compliant and potentially unsellable.

How Does This Impact Costs?

Expect fees to include:

• Professional site inspections
• Compliance checks
• Additional liability & responsibility

Tip: Combining Contract Administration and Principal Designer roles with your architect is the most cost-effective solution — protecting your build and budget.

6. How Hiring an Architecture Firm or Architectural Technologist Saves You Money

Beyond design, professional oversight adds value, prevents costly mistakes, and keeps your project on track.

Here’s how:

Budget Control: Design within your budget — avoid over-specification
Avoid Builders’ Guesswork: Builders need detailed drawings for accurate quotes
Competitive Tendering: Multiple quotes based on the same design — real market value
Variation Control: Manage changes properly — stop costs creeping up
Defect Management: Spot poor workmanship early and hold back payments if needed

Are builders overcharging?

Bottom Line: Professional fees often save you more than they cost — through better quality, budget control, and regulatory compliance.

Final Thoughts – Are Architecture Fees Worth It?

Knowing how much architecture firms charge in 2025 helps you plan and protect your investment.

RIBA Chartered architects and technologists ensure compliance
Principal Designer is now legally required
Full service prevents costly rework and poor construction quality

Frequently Asked Questions (FAQs)