That’s why we place planning strategy at the heart of our design process. With years of experience working across London and the UK on homes of all types and ages—from terraced Victorian houses to detached post-war properties and listed buildings—we know how to navigate the system, anticipate obstacles, and craft proposals that are not only beautifully designed but also planning-compliant.

This guide focuses specifically on the planning process: what it involves, the challenges it presents, and how Material Works helps you move through it with clarity and confidence.

Do I Always Need Planning Permission for a House Extension?

Not always. Many common types of small house extensions fall under Permitted Development (PD) rights - rules set by the government that allow homeowners to carry out specific works without planning consent. We will advise at the earliest stage wether we believe your proposed project falls within PD rights or if a full application is required.

When permitted development rights do apply, we advise client to confirm this by applying for a Lawful Development Certificate (LDC) from the local authority. This is a standard procedure that prevents any uncertainty and is often required to confirm building works when a property is sold. Material Works will prepare and submit all information for the LDC. See our guide to Permitted development rights.

When Is Planning Permission Required for an Extension?

You’ll need full planning permission if your proposed extension:

Will extend more than 6 metres from the rear wall of a semi-detached or terraced house (or more than 8 metres for a detached house)
Is over 4 metres high on the rear wall
Is a two-storey extension within 7 metres of a rear boundary
Covers more than half the garden area
Is located on the front or side, facing a highway
Uses materials not in keeping with the existing house
Includes a balcony, veranda, or raised platform
Is in a conservation area, national park, AONB, or World Heritage Site
Is to a listed property
Is to a flat or maisonette
If PD rights have been removed in the area via an Article 4 Direction

Early assessment is essential—and that’s where we begin.

How Material Works Helps You Succeed

The planning process isn’t just a tick-box exercise. It’s a negotiation between your aspirations and local authority policies, design guidance, heritage concerns, and neighbour impact. A successful application depends on design quality, planning insight, and strategic thinking.

At Material Works, we:

Undertake in-depth local policy and precedent research for your site
Analyse site history, previous applications, and potential constraints
Engage with planning officers when appropriate
Craft well-reasoned, clearly presented proposals with strong design rationale
Prepare and manage all application materials to professional standards

Our goal is to help you avoid common pitfalls, reduce the likelihood of refusal, and secure permission with minimal delay.

The Stages of the Planning Process

1. Feasibility and Planning Review

Before any design work begins, we review your site’s planning context. We check:

Whether Permitted Development Rights apply
Conservation area or listed status
Planning history of the property and surrounding homes
Local and national planning policies
Recent approvals and refusals nearby

This research allows us to identify risks early and advise you on what is likely to be supported—and what’s not.

2. Concept Design with Planning in Mind

We develop initial concept designs that align with both your brief and the planning context. These designs are not only about function and beauty—they are crafted with a clear understanding of what’s likely to gain approval.

Where appropriate, we shape the design in ways that reduce planning risk, such as:

Setting back or stepping down volumes to reduce visual impact
Selecting materials that respond to local character
Improving privacy relationships with neighbouring homes
Minimising massing in sensitive views

We treat design and planning strategy as one and the same—never an afterthought.

3. Pre-Application Engagement (Optional but Strategic)

For more complex or sensitive proposals—particularly in conservation areas or where local policies are restrictive—we may recommend a Pre-Application Submission.

This informal process allows us to present a proposal to the planning officer and receive feedback before submitting a full application. While not legally binding, it can highlight concerns, allow us to address them in advance, and demonstrate a collaborative approach.

Material Works has developed positive working relationships with planners across multiple boroughs, and we know how to frame discussions constructively.

4. Preparing the Planning Application

We manage every aspect of the application submission, including:

Measured surveys and accurate drawings of existing conditions
Proposed design drawings, including plans, elevations, and sections
A detailed Design and Access Statement, articulating the design rationale and policy compliance
Heritage or sustainability statements where relevant

We ensure every application is professionally presented, visually clear, and carefully worded—critical factors in helping planning officers assess the scheme fairly.

5. Managing the Determination Period

Once submitted, the council has 8 weeks (for householder applications) to make a decision. During this time:

Neighbours are consulted
The case officer reviews the submission against policy
Site visits may occur

We remain available to address any follow-up requests from officers, provide clarifications, and keep you updated throughout.

6. Decision and Next Steps

If permission is granted, we move the project into the technical design phase. If changes are requested during the application process we can quickly facilitate these to prevent the application slowing.

While we pride ourselves on success rates, refusals can occur when we are pushing at the boundaries of policy requirement or working in unusual contexts. In these instances we would have clearly explained the risks prior to submitting and advised on a secondary route - for instance reducing the scale or scope of works, or reverting to a more conventional detail. We can then assist you with a re-submission that addresses reasons for refusal.

In other instances, if we feel that the local authority have acted unreasonably in refusing the scheme, we can prepare and submit an appeal. This can be a slower process, but we have had success following this routes to ensure the optimal outcome for our clients.

Our success rate is high because we don’t leave planning to chance. We guide the design to work with the system, not against it.

Planning With Purpose: Our Ethos

At Material Works, we believe that gaining planning permission should not come at the expense of quality, sustainability, or creativity. We specialise in:

Natural materials that age gracefully and reduce environmental impact
Healthy living environments, filled with natural light, clean air, and calm spatial flow
Low-carbon strategies that make homes more efficient and future-ready
Contextual but contemporary design, rooted in place, proportion, and craft

Because planning authorities increasingly value sustainability and design integrity, our approach often strengthens your application—not just aesthetically, but strategically.

Talk to Us Early

If you’re considering extending or adapting your home, involving us early in the process will give you the best chance of planning success. Our experience, professionalism, and design-led strategy help make a complex process straightforward—and ultimately rewarding.

Contact Material Works to arrange an initial conversation. Let’s work together to secure a smart, sustainable future for your home.