Conservatories have always been one of the most popular ways to maximise a property’s space. Nonetheless, getting the green light to build one isn’t always as straightforward as it seems. Single-storey extensions are usually permitted without planning permission, provided they meet certain conditions. However, when construction plans breach these conditions, homeowners have to jump several hurdles before they can begin building their dream conservatory. In this article, we’ll dive into conservatory specifics and outline when planning permission is required.

With over 20 years of experience building conservatories in Harpenden and surrounding areas, the CS Windows team are expertly placed to guide you through the details of conservatory construction.

Do You Need Planning Permission For A Conservatory: Complete Guide

With so many rules and regulations, it can be difficult to understand when you need planning permission and when you don’t. This extensive guide aims to clear up your construction queries and help you start building your dream conservatory.

cs windows modern conservatory

What Is Planning Permission?

Planning permission is the approval of local authorities to allow the building of, or changes to, a building. Sometimes referred to as planning consent, each local authority has a different approach to the rules. It’s important to know who your local authority is so you can understand how they approach planning permission – this can be done here. Each local authority has a different set of planning permission rules dependent on the context of the area. For example, authorities in Areas of Natural Beauty are far more strict when granting planning permission as they want to preserve the landscape.

The planning permission rules vary depending on the type and scale of construction. Going ahead with a project that requires planning permission before gaining consent can have serious consequences. Often, you will be forced to demolish the building work or put it right later, which will be very costly. It’s also important to understand that properties that have undergone illegal work are unmortgageable, meaning they’re almost impossible to sell. Regardless of the project you intend to undertake, it’s always best to contact your local planning department before you proceed.

planning permission document

What Is Permitted Development?

Often, construction projects will fall under permitted development. These rules allow homeowners to build on a smaller scale without applying for planning permission. Conservatories and single-storey extensions usually fall under permitted development, meaning homeowners are free to build them without approval from their local authority.

If you live in a designated area, you may find that your permitted development rights are restricted. Designated areas have extra scrutiny attached to any renovation or extension work, often because the local authorities are trying to preserve the area’s current state. Designated areas include Conservation Areas, Areas of Outstanding Natural Beauty or National Parks.

Permitted development rights fall into five categories:

Class A: Extensions

  • A single-storey side extension up to half the width of the existing property.
  • A single-storey rear extension up to 8m in length for a detached property and 6m long for a semi or a terraced house.
  • In some instances, 3m two-storey rear extensions.

Class B: The Roof
Rear dormers and hip-to-gable extensions can be created if the additional volume does not exceed 50m3 (or 40m3 in the case of semis or terraced homes).

Class C: Other Roof Altercations

Class D: Porches

Class E: Outbuildings
Outbuildings can be built within residential grounds, provided they sit behind the property and do not cover more than 50% of the grounds. They can’t be any more than 3m in height (4m for dual-pitched roods or 2.5m if within 2m of the property’s boundary.

building regulation papers

Do I Need Planning Permission For A Conservatory?

Conservatories fall under class A of the permitted development rights. That means you can build a conservatory without planning permission if it is a maximum height of 4m (3m if it’s within 2m of a boundary). It’s also essential that your planned conservatory does not cover more than half of your garden.

You will need planning permission to build your conservatory at the front of your house. This refers to the front of the ‘original house’ as it stood on 1st July 1948.

If you’re still unsure whether you’ll need planning permission for your new conservatory, check out the guides provided by Planning Portal. Their interactive 3D tool helps you plan home improvement projects, allowing you to take the first steps in constructing your conservatory.

open conservatory in Harpenden

Do You Need Planning Permission To Change A Conservatory Roof?

Simply put, you no longer need planning permission to change a conservatory roof. Previously, specific percentages of the roof had to be translucent to be exempt from planning permissions. However, the new rules allow homeowners to change their conservatory roof without further planning permission applications.

Despite this, roof reconstructions must continue to follow the limitations that all single-storey extensions adhere to. This means the conservatory cannot extend past the property’s rear wall, and the roof cannot exceed the height of the main property.

Homeowners should also consider the structural integrity of their current conservatory and whether a roof replacement will negatively impact these foundations. At CS Windows, all of our conservatories come with a ten-year warranty, so it’s also important to understand how a roof renovation might impact this guarantee.

conservatory roof

How Do I Apply For Planning Permission For A Conservatory?

If your planned conservatory does require planning permission, you’ll need to file a planning application with your local authority. Each authority has its own system for filing an application, which can usually be found online. Most authorities now use the Planning Portal application system to accept requests for planning permission. This usually involves an application fee, and the total cost can be calculated using the fee calculator provided.

Along with an application form, you will need to include the following information:

  • Location plan.
  • Site plan.
  • Elevations of both the existing and the proposed designs.
  • An ownership certificate.
  • A design and access statement.
  • An ‘Agricultural Holdings Certificate’. This confirms whether any land relating to the application is part of an agricultural holding and is necessary even for non-agricultural use applications.
  • The correct fee. This depends on your location. The typical price for an extension in the UK is £206.

A decision on your planning application should arrive within 8 weeks of submission. A successful planning permission application lasts three years from the date full consent is given. You must begin working within this time, but once you do, the planning permission lasts forever.

handing papers over

Do You Need Building Regulations For A Conservatory?

Building regulations ensure new buildings, conversions, renovations, and extensions are safe. To increase compliance levels, the Government has produced approved documents that offer guidance on how to meet these standards.

These regulations will apply if you’re adding an extension to your home. However, a conservatory is not usually subject to building regulations, provided it meets specific requirements:

  • It’s built at ground level with a floor area of no more than 30 square metres.
  • At least 50% of the new wall and 75% of the roof are glazed or use translucent material.
  • Elevations of both the existing and the proposed designs.
  • The external walls or windows separate the conservatory from the house.
  • Any fixed electrical installations meet the requirements of the applicable building regulations.
  • The heating system is independent of your home, with separate temperature and on/off controls.

In June 2022, new rules were enacted to reduce emissions released by property extensions. These regulations aim to mitigate overheating in homes by limiting solar gains. New conservatories must now be able to demonstrate they will not generate unwanted solar gains in summer if they are to avoid building regulations. Homeowners can achieve this by installing energy-efficient solar control glazing and ventilation systems like roof vents.

If you need clarification on whether your conservatory requires building regulations approval, contact us at CS Windows. With 20 years of experience building conservatories in St Albans, our team are building regulations experts.

open modern conservatory

Construction With Confidence

As with any construction project, in-depth planning is crucial before starting the build. Homeowners intending to build their own conservatory should spend considerable time understanding their development rights before the work begins. These rights can vary massively between properties, so finding those specific to your home is key.

That said, permitted development rights offer plenty of flexibility when constructing conservatories and single-storey extensions. Provided the conservatory follows the class A regulations, homeowners can usually build their desired extension without expressed consent from local authorities. Not only that, but most standard conservatories aren’t subject to building regulations. This means conservatory construction is typically far more straightforward than most development projects.

Navigating the world of planning permissions and building regulations can be very difficult without seeking expert advice. That’s why our expert team at CS Windows is just a phone call away. We’ve built a reputation for constructing high-quality conservatories in line with your property’s regulations. Get in touch for a free design consultation for complete transparency before moving forward with the build.