Preparation and Brief: Setting the Foundation
Build your professional team, investigate your property thoroughly, and develop a detailed project brief. This stage transforms your vision into a workable project.
Professional Foundation
5 key areas to establish
💡 This stage typically takes 4-8 weeks to complete properly
What You Need to Do First
Four critical tasks to establish the professional foundation for your project.
Find 3 Architects to Interview
Get quotes and portfolios from experienced extension architects
Action:
Search RIBA Find an Architect, check local recommendations, review recent extension projects in your area.
💡 Look for architects with 5+ London extension projects in their portfolio
Commission a Measured Survey
Get accurate drawings of your existing property
Action:
Contact measured building surveyors. Budget £800-1,500 for typical London house.
💡 Do this early - architects need accurate drawings to start design work
Check Title Deeds and Covenants
Identify any legal restrictions on your property
Action:
Download title deeds from Land Registry (£3). Look for restrictive covenants.
💡 Some properties have covenants preventing extensions or requiring neighbor consent
Write a Detailed Project Brief
Document exactly what you want to achieve
Action:
Expand your Stage 0 notes. Include room sizes, budget, timeline, and preferences.
💡 The clearer your brief, the better your architect can design for you
Order Matters
Start with architect interviews first - they can guide you on surveys and help develop your brief. Don't commission surveys until you've appointed your architect, as they may have preferred surveyors.
Why Professional Preparation is Critical
Poor preparation in Stage 1 causes the majority of project failures. Here's why getting it right matters.
The Right Architect Saves You Money
A good architect prevents costly mistakes, maximizes your property value, and navigates planning efficiently.
Real impact: Wrong architect choice costs the average project £15,000-£30,000 in design changes and delays.
Measured Surveys Prevent Design Disasters
Accurate measurements are essential for proper design. Guesswork leads to expensive construction problems.
Real impact: Projects without proper surveys face 40% more on-site variations and cost overruns.
Legal Issues Kill Projects
Unknown covenants, party wall issues, or boundary disputes can stop your project completely.
Real impact: 1 in 8 extension projects discover legal issues that require major changes or cancellation.
Clear Briefs Get Better Results
Detailed briefs ensure your architect designs what you actually want, not what they think you want.
Real impact: Projects with detailed briefs require 60% fewer design revisions and finish on time.
The £20,000 Investment
Stage 1 typically costs £3,000-£5,000 for surveys and initial fees. Skipping or rushing this stage costs the average project £20,000+ in delays, design changes, and legal issues. It's the best investment you'll make.
How to Choose the Right Architect
Your architect is the most important decision you'll make. Here's how to choose wisely.
Portfolio Review
- Minimum 5 completed extensions in London
- Similar project types to yours (Victorian terrace, modern house, etc.)
- Evidence of planning permission successes
- Quality of design and attention to detail
Experience & Qualifications
- ARB registered architect (check ARB website)
- Experience with your borough's planning department
- Understanding of local building regulations
- Party wall experience for London properties
Fee Structure & Services
- Clear fee structure (usually 8-15% of construction cost)
- Services included at each RIBA stage
- Additional costs for planning applications, site visits
- Payment schedule aligned with project milestones
References & Communication
- Recent client references (within last 2 years)
- Response time to emails and calls
- Clarity in explaining design decisions
- Willingness to listen to your requirements
Interview Questions to Ask
Key questions: How many extensions have you done in my borough? Can you show me planning approvals? What's your typical timeline? How do you handle cost overruns? Can I speak to your last 3 clients?
Red flags: No local experience, vague about fees, can't provide recent references, promises unrealistic timelines, or seems uninterested in your specific requirements.
Essential Site Investigations
Professional surveys and investigations that inform your design and prevent costly surprises.
Measured Building Survey
£800-£1,500Professional survey of existing building
Includes:
- ✓Accurate floor plans of all levels
- ✓Elevations of all sides
- ✓Site plan showing boundaries
- ✓Level surveys and key dimensions
Structural Assessment
£500-£1,200Evaluate existing structure condition
Includes:
- ✓Foundation type and condition
- ✓Wall construction and load-bearing elements
- ✓Roof structure assessment
- ✓Identification of any existing issues
Services Investigation
£300-£800Map existing utilities and drainage
Includes:
- ✓Location of incoming services (gas, electric, water)
- ✓Drainage system mapping
- ✓Identification of any adoptable sewers
- ✓Assessment of capacity for extension
Soil Investigation
£800-£2,000Ground conditions for foundations (if needed)
Includes:
- ✓Soil bearing capacity
- ✓Groundwater levels
- ✓Contamination screening
- ✓Foundation design recommendations
Which Surveys Do You Need?
Essential: Measured building survey (every project needs this).Usually needed: Structural assessment (especially for older London properties).Sometimes needed: Soil investigation (large extensions, poor ground), Services investigation (complex projects).
London-Specific Considerations
Unique challenges and requirements for London extension projects that you need to plan for.
Party Wall Matters
Essential for terraced and semi-detached properties
💡 Start party wall discussions early - they can't begin until you have detailed plans
Action Items:
- Identify which neighbors are affected
- Understand the Party Wall Act process
- Budget £2,000-5,000 for party wall procedures
- Allow 2-3 months for the process
Thames Water Agreements
Required for work near public sewers
💡 Common in London - 30% of extensions require Thames Water approval
Action Items:
- Check Thames Water sewer maps for your property
- Identify if build-over agreement needed
- Submit application with detailed proposals
- Allow 6-8 weeks for approval
Access and Logistics
Construction access in dense London areas
💡 Some London properties have no rear access - affects construction costs significantly
Action Items:
- Assess vehicle access for deliveries
- Consider skip placement and permits
- Evaluate scaffolding requirements
- Plan for material storage limitations
Borough-Specific Requirements
Each London borough has unique policies
💡 Some boroughs require specific consultant reports (daylight/sunlight, heritage, etc.)
Action Items:
- Review borough residential design guide
- Check for pre-application advice services
- Understand local CIL charging policies
- Research recent appeal decisions in the area
Ready for Stage 2?
With your team assembled and property investigated, it's time to develop design concepts that bring your vision to life.
Next: Stage 2 - Concept Design