Architect stages for your loft conversion project
Please note that these stages are for guidance only. To get a clear, stage-by-stage cost breakdown of your project, simply post your loft conversion project and get up to 5 free quotes from specialists in your area.
Preparation, Briefing & Feasibility
Understanding your goals and exploring what's possible
Planning & Statutory Approvals
Securing permission and finalising your loft's external design
Technical Design & Specification
Turning your design into construction-ready detail
Construction & Handover
Overseeing the build and ensuring a high-quality finish
Loft Conversion Project – Roles & Responsibilities
(Architect • Structural Engineer • Builder)
A loft conversion is one of the most rewarding ways to add space and value to your home — but it requires careful coordination between design, structure, and construction. This guide explains how each professional contributes at every stage.
Preparation, Briefing & Feasibility
Confirm the loft is suitable for conversion and establish what's possible within your home, budget, and local planning rules.
Planning & Statutory Approval
Develop and submit the design for planning approval (or a lawful development certificate) and coordinate initial structural input.
Technical Design & Specification
Produce detailed technical drawings and structural designs that meet Building Regulations and allow accurate builder pricing.
Construction & Handover
Build and deliver the loft safely and accurately according to the approved design.
How They Work Together
Architect
Designs and coordinates the entire process — from concept to completion.
- •Manages planning, Building Control, and contract administration.
- •Oversees quality, safety, and compliance throughout.
Structural Engineer
Ensures the structure (beams, joists, dormer supports) is strong and safe.
- •Provides precise calculations and drawings for approval.
- •Supports architect and builder during construction with technical advice.
Builder
Delivers the physical build according to the approved plans.
- •Manages the day-to-day work, sequencing, and workmanship on site.
- •Keeps client informed and ensures timely delivery.
Together, they turn unused loft space into a comfortable, compliant, and beautiful new living area.
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Architect step-by-step cost guide for your loft conversion project
Please note: All figures provided are rough guides only. To receive a clear, stage-by-stage cost breakdown tailored to your project, simply post your project today and get up to 5 free quotes from local specialists.
(Helping you understand what you'll pay and when)
Architects' fees for loft conversions can vary depending on the project size, complexity, location, and the level of service you choose. This simple guide explains what your architect does at each stage — and what costs to expect.
Feasibility & Concept Design
(Exploring what's possible and shaping your vision)
Planning / Lawful Development Stage
(Securing approval for your design)
Building Regulations & Technical Design
(Turning plans into construction-ready detail)
Construction & Site Support (Optional)
(Overseeing the build and ensuring quality)
Summary – Typical Overall Architect Fees
| Level of Service | Estimated Cost Range | What's Included |
|---|---|---|
| Basic Design Service | £1,500 – £3,000 | Concept + Planning Drawings only |
| Design + Building Regs Package | £2,200 – £4,000 | Full planning and technical drawings |
| Full Architectural Service | 8% – 15% of total build cost | Design, planning, building regs, tender, and site support |
Basic Design Service
£1,500 – £3,000
Concept + Planning Drawings only
Design + Building Regs Package
£2,200 – £4,000
Full planning and technical drawings
Full Architectural Service
8% – 15% of total build cost
Design, planning, building regs, tender, and site support
Example: For a £50,000 loft conversion, full architectural fees typically range between £4,000 – £7,500, depending on complexity and location.
Key Factors That Affect Cost
- •Project complexity: Simple Velux conversions are cheaper than large dormers or mansards.
- •Location: Fees in London tend to be 10–20% higher.
- •Scope of service: Full project management adds cost but provides complete oversight.
- •Property type: Listed buildings or homes in conservation areas require extra documentation and expertise.
✅In summary:
A good architect not only designs your loft beautifully but also ensures it's structurally sound, fully compliant, and efficiently managed — helping you avoid costly mistakes and delays.
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