If you own, or are thinking about buying, a listed building, one of the first things you will notice is that it has a “grade” attached to it. Grade I, Grade II* or Grade II. For many people, those labels feel vague and slightly intimidating, especially when you start thinking about making changes.
What do these grades actually mean? Do they affect what you can and cannot do? And how much difference is there in practice between them?
This guide explains the different grades of listed buildings, what they signify, and how they influence the planning and consent process.
What does it mean for a building to be listed?
A listed building is protected because it has special architectural or historic interest. Listing is not about freezing a building in time, but about managing change in a way that protects what makes it important.
The protection applies to:
The whole building, inside and out
Original features such as staircases, fireplaces and windows
Later additions that have become part of its history
Outbuildings and structures within the curtilage
That means work which would normally be straightforward in a modern house, such as changing layouts or replacing windows, can become much more sensitive in a listed one.
The grade of listing gives an indication of how important the building is in national terms, and that affects how strictly change is assessed.
The three grades of listed buildings
In England and Wales, listed buildings fall into three categories. These are not quality ratings, but levels of heritage significance.
Grade I – Buildings of exceptional interest
Grade I buildings are the most important and make up a very small percentage of all listed buildings. These are buildings of outstanding national importance, often with very high levels of originality and historic value.
Typical examples include:
Cathedrals and churches
Major manor houses
Medieval halls and castles
Important civic buildings
Changes to Grade I buildings are possible, but they are examined very carefully. Proposals must be extremely well justified and designed with great sensitivity. Even small alterations can have a significant impact on how an application is assessed.
Grade II* – Particularly important buildings
Grade II* buildings sit between Grade I and Grade II. They are particularly important buildings of more than special interest and often retain high levels of original fabric.
These might include:
Large historic houses
Important townhouses
Buildings with rare features
Well-preserved examples of a particular period
While there may be slightly more flexibility than with Grade I, proposals still need to be handled with care. Alterations are judged against how they affect the most significant parts of the building, such as main rooms, staircases, or original structural elements.
Grade II – Buildings of special interest
Grade II buildings make up the majority of listed buildings. They are still considered nationally important, but there is often more scope for change, depending on the building’s condition and history.
Examples include:
Period cottages
Farmhouses
Georgian and Victorian townhouses
Converted historic buildings
Although there can be more flexibility, consent is still required for works that affect the character of the building. Original features such as windows, fireplaces, floor structures and roof forms remain protected.
Grade II does not mean “light touch”. It still requires:
Careful design
Clear justification
Appropriate materials
Thoughtful handling of historic elements
Does the grade control what you can do?
In simple terms, yes, but not in a fixed or formulaic way.
The grade gives an indication of how sensitive the building is likely to be, but the real test is how important the part you are changing is to the building’s character.
For example:
Altering a later rear extension may be acceptable on any grade
Changing a principal staircase may be difficult even on a Grade II building
Removing original windows is sensitive regardless of grade
Internal layout changes may be acceptable if they avoid key features
What matters most is:
Which part of the building is affected
How important that part is
Whether the change is necessary
Whether harm can be avoided or reduced
This is why a building’s grade should be seen as a starting point, not a final answer.
How grades affect the consent process
The higher the grade, the more detailed and careful the application usually needs to be.
This can mean:
More detailed heritage assessment
Greater focus on original fabric
Stronger justification for change
More scrutiny from conservation officers
Longer discussions about materials and detailing
For homeowners, this does not mean change is impossible. It simply means the process needs to be approached with care and structure.
A well-prepared application for a Grade I or II* building can succeed, just as a poorly prepared application for a Grade II building can fail.
Common misunderstandings
“Grade II means I can do what I want.”
Consent is still required for works that affect character.
“Grade I buildings cannot be altered.”
They can be, but proposals must be extremely well justified and carefully designed.
“The grade only affects the outside.”
Listing applies to the whole building, including the interior.
“If it’s not in the listing description, it’s not protected.”
The description is a guide, not a limit.
Understanding these points early avoids expensive mistakes later.
How professional support helps
GRK Architecture helps clients understand what the grade of their listed building means in practical terms, so decisions are based on clarity rather than guesswork.
Support includes:
Interpreting how the grade affects what can be changed
Designing proposals that respect the building’s character
Preparing clear heritage justification
Submitting well-prepared applications
Managing discussions with conservation officers
This reduces risk, improves design quality, and increases the likelihood of consent, while making the process far less stressful for homeowners.
Final thoughts
The grade of a listed building is not a barrier, it is a way of understanding how important that building is and how carefully it should be treated.
Whether a building is Grade I, Grade II* or Grade II, the same principle applies. Change is possible, but it needs to be justified, proportionate and sensitive to what already exists.
With the right approach, it becomes possible to improve how a historic building works as a home while protecting what makes it worth preserving.
As heritage and listed building architects we support out clients through this process, helping turn complex heritage controls into clear, manageable steps towards approval.
