What is Class G of the GPDO?

Class G of the General Permitted Development Order (GPDO) is one of the most underutilised yet commercially powerful planning tools available to property owners in England.

While other permitted development rights—particularly Class MA—have received widespread attention, Class G remains a highly targeted and often more straightforward route to unlocking residential value from existing commercial buildings.

This article provides a comprehensive, guide to Class G, explaining not just what the legislation allows, but how it is applied in practice, where schemes succeed or fail, and how it can be strategically deployed alongside other permitted development rights.

What is Class G of the GPDO?

Class G permits the change of use of part of a building from:

• Class E (commercial, business and service uses); or

• Sui generis uses such as betting offices or payday loan shops

to a mixed-use building, comprising:

• A continued commercial use at ground floor level; and

• Up to two self-contained flats on the upper floors

In simple terms, Class G allows you to retain an active commercial frontage while introducing residential accommodation above—a traditional and policy-supported form of development that aligns with high street regeneration objectives.

Why Class G Matters

From a development and investment perspective, Class G offers several distinct advantages:

• No requirement for full planning permission (subject to Prior Approval)

• No minimum vacancy period or use test

• No explicit floorspace cap on the residential element

• Applies in a wide range of locations, including conservation areas

• Retains commercial income while introducing residential value

For property owners and investors, this creates an opportunity to:

• Enhance asset value

• Diversify income streams

• Optimise underutilised upper floors

Key Class G Planning Framework

Class G sits within Schedule 2, Part 3 of the GPDO and is subject to a series of conditions and limitations. Understanding these is critical to determining whether a scheme is lawful.

1. Mixed-Use Configuration

The development must result in a genuine mixed-use building, meaning:

• The commercial use must be retained at ground floor level

• Residential use must be located above the commercial unit

• You cannot convert the ground floor into residential under Class G

This reflects long-standing national and local policy support for active ground floor frontages, particularly within town centres.

2. Maximum Number of Flats

Class G allows for a maximum of two flats per planning unit.

However, a key strategic opportunity arises where a building can be subdivided into separate planning units vertically.

In such cases, each unit may benefit from its own Class G allowance—subject to careful consideration of planning unit definition and lawful use.

3. The “Ancillary Use” Requirement

A critical—and often misunderstood—requirement is that the upper floors must form part of the same planning unit as the commercial use below.

In practice, this means the upper floors should be ancillary to the primary commercial use. Typical examples include:

• Storage space

• Staff offices

• Break rooms or administrative areas

If the upper floors have been separately let, independently accessed, or used as a distinct planning unit, they may fall outside the scope of Class G.

This is one of the most common reasons for refusal or lawful development challenges.

The Prior Approval Process

Class G development requires submission of a Prior Approval application to the local planning authority.

Key Parameters:

• Fee: £240 per dwelling

• Determination period: 56 days. If a council fails to determine any prior approval application within this statutory period, the developer can proceed with development which is Permitted Deleopment, but caution is required - development which is not in fact permitted by the GPDO cannot proceed. A secondary Certificate of Lawfulness may be required under that scenario.

Matters for Prior Approval Assessment

The scope of assessment is deliberately narrow and limited to the following:

1. Contamination risks

2. Flood risk

3. Noise impacts from commercial premises

4. Provision of adequate natural light in all habitable rooms

5. Waste storage and management arrangements

Importantly, the authority cannot consider wider planning merits, such as:

• Design and appearance

• Loss of commercial floorspace

• Housing mix

• Transport and parking impacts

This constrained assessment framework is what makes Class G a powerful and predictable route to development.

Key Technical Considerations

Contamination Risk

Contamination is usually a low-risk issue for Class G, particularly as residential use is on upper floors.

• Main concern: Whether historic uses (e.g. garages, dry cleaners, fuel storage) could pose a risk to occupants

• Typical requirement, where necessary: A Phase 1 Desk Study reviewing site history

Flood Risk

Flood risk can be more material, depending on location.

• Flood Zone 1: Typically straightforward

• Flood Zones 2–3: Likely to require a Flood Risk Assessment (FRA)

• Key advantage: Flats are above ground level, reducing risk to occupants

The main test is whether the development is safe and accessible during a flood event.

Noise

Noise is often the most technically challenging aspect of a Class G scheme.

• The assessment relates specifically to noise from the commercial use within the building, not external sources such as traffic

• Uses such as restaurants, gyms, or late-night premises may require acoustic mitigation measures

• A Noise Impact Assessment may be necessary

Natural Light

Each habitable room must benefit from adequate natural light.

• Poorly configured layouts or deep-plan buildings may struggle to comply

• This has become a significant refusal reason in recent years

Waste Storage

Waste provision is a practical but critical issue. Adequate on-site storage must be identifie. Collection arrangements must be workable and policy-compliant

In constrained urban sites, this can be a determinative constraint

Location and Heritage Considerations

Unlike many other permitted development rights, Class G:

• Applies in conservation areas

• Applies in National Parks and AONBs

• Can apply to listed buildings (subject to separate Listed Building Consent)

This makes it particularly valuable in historic town centres, where traditional shop-top housing is both characteristic and policy-supported.

Common Pitfalls and Reasons for Refusal

Despite its advantages, Class G is not without risk. Common issues include:

• Failure to demonstrate ancillary use

• Inadequate natural light provision

• Poor waste storage arrangements

• Unresolved noise impacts

• Incorrect interpretation of the planning unit

These risks highlight the importance of early-stage due diligence and professional input.

Practical Example

A typical successful Class G scheme might involve:

• A high street retail unit with underutilised storage above

• Internal reconfiguration to create two one-bedroom flats

• Retention of the retail unit at ground floor

• Submission of a Prior Approval application supported by appropraite techncial reports.

Such schemes are often low-cost, high-return interventions, particularly in secondary retail locations.

Planning Strategy and Professional Advice

While Class G appears straightforward, its successful implementation depends on the correct interpretation of the GPDO.

Professional planning advice can confirm whether a property qualifies and structure applications to minimise risk

Class G Final Thoughts

Class G represents a precise and effective mechanism for delivering residential development in sustainable locations while maintaining active commercial uses.

In an era of high street transition and housing need, it offers a low-risk route to intensification—particularly where upper floors are vacant or underutilised.

However, its success relies on a clear understanding of the legal framework, particularly the ancillary use requirement and the technical aspects of Prior Approval.

Contact Me About Your Class G Project

If you are considering a Class G development, I can provide:

• Initial feasibility advice

• Planning strategy and risk appraisal

• Preparation and submission of Prior Approval applications

About me

Andrew Ransome is the planning director at ADP and is a chartered member of the RTPI, with over 22 years of town planning experience.

Andrew has extensive experience offering strategic planning solutions to challenging projects in both rural and urban settings. Follow him on Linkedin.

Get in touch