Architectural designers and planning consultants

A successful project is not a product — it is a structured process.

If you are thinking about hiring someone for your house extension project, keep in mind that you are investing in independent judgment, strategic thinking, regulatory knowledge, and years of experience in designing buildings and navigating an increasingly complex planning system.

At Chiltern Planning Consultants, every project follows a clear and carefully managed pathway designed to reduce risk, improve planning outcomes, and support a well-coordinated build.

A Structured, Stage-Led Approach

While every project is different, our methodology typically moves through the following phases:

1. Strategic Definition
   We begin with feasibility. Before design work starts, we assess planning policy, constraints, site conditions and development potential. This ensures your brief is realistic, policy-aligned and financially considered from the outset.
2. Brief & Service Agreement
   Once feasibility is established, we define scope, level of involvement and agreed fees. Some clients require planning drawings only; others need full technical coordination through to construction. Our service adapts to your needs.
3. Concept Design & Planning Strategy
   Measured surveys, concept development and coordinated input from specialist consultants where required. We refine the scheme collaboratively before preparing a robust planning submission.
4. Planning Submission & Management
   Applications are prepared thoroughly to minimise risk and avoid unnecessary delays. Given current pressures within many Local Planning Authorities, getting it right first time is critical.
5. Technical Design & Compliance
   Following approval, we develop construction information aligned with Building Regulations, structural requirements and coordinated specifications — providing clarity for contractors and cost control.
6. Construction Support (As Required)
   Tender review, contractor coordination and liaison with Building Control can be included depending on your chosen level of service.
7. Completion & Sign-Off
   Final approvals, compliance confirmation and structured project close-out.

Why We Start With Feasibility

Planning permission is becoming increasingly complex. National policy, local development plans, Article 4 Directions, Green Belt, National Landscapes, conservation areas and site-specific constraints all influence what can realistically be achieved.

An early feasibility stage allows us to identify risk before design costs escalate. It ensures the project brief aligns with policy, budget and buildability — not just aspiration.

This upfront strategy is one of the key reasons our projects progress efficiently.

Our Approach to Fees

There is no one-size-fits-all design fee — just as there is no one-size-fits-all extension.

Fees are influenced by:

• Project scale and complexity
• Planning constraints and site conditions
• Level of design detail required
• Consultant coordination (structural, ecological, arboricultural etc.)
• Extent of involvement through planning, technical and construction stages

Rather than applying a rigid percentage model, we estimate time based on experience from comparable projects and formalise this within a clear Service Agreement. This provides transparency and cost certainty from the outset.

Collaboration, Not Over-Management

We do not operate as heavy project managers. Many of our clients prefer to remain actively involved in design decisions, finishes and contractor relationships. Our role is to provide strategic guidance, technical coordination and planning clarity — without unnecessary overhead.

However, deeper engagement can be provided where required.

Want to Understand the Process in Detail?

The above is a summary of how we structure projects.

If you would like a more detailed breakdown of our staged workflow, time allocations and service structure, we are happy to provide our full “How We Work” document as a PDF upon request.

Please contact us directly and we will forward a copy.

Below are estimates for hours.

Feasibility Studies 5-45 hours.
Survey and Design 16-70 hours.
Construction Drawings 14-90 hours.
Tendering Drawings & Specifications 8-40 hours.
Structural Fees £POA.
Householder Planning £528 + submission fees.
Lawful Development Certificate (Proposed) £264 + submission fees.
Boundary/Outbuilding Works £262 + submission fees.

Fees for Planning Applications in England

For a more detailed breakdown on planning fees the Planning Portal has a guidance sheet which can be found here