architects FROM LONDON Single-storey Extensions
Add Valuable Space Without Changing the Whole Character of Your Home
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Single-storey Extensions intro
Add Valuable Space Without Changing the Whole Character of Your Home
A single-storey extension can create the extra space your home needs without the scale or complexity of adding another floor.
It can be used to enlarge a kitchen, create a new dining area, add family living space, improve access to the garden or completely reorganise the ground-floor layout.
At Tholos Architects, we design single-storey extensions around the way the existing house works, not just the amount of extra space you want to add.
A well-designed single-storey extension can help you:
- Create a larger kitchen
- Add a kitchen-dining space
- Build a family room
- Improve natural light
- Create better garden access
- Add a utility room
- Improve storage
- Create a home office
- Reorganise the ground floor
- Improve circulation
- Make better use of existing rooms
The extension should feel like part of the home, not simply an extra room attached to it.
Single-storey Extensions explained
What Is a Single-storey Extension?
A single-storey extension adds additional accommodation at ground-floor level.
It may be built:
- To the rear of the property
- To the side
- Around the side and rear
- To the front
- Across part of the existing building
- As part of a wider renovation project
Single-storey extensions can range from relatively small additions to substantial changes that completely reshape the ground floor.
The most appropriate solution depends on:
- The existing property
- Available external space
- Planning restrictions
- Your budget
- The rooms you want to create
- How you want the home to function
Why Build a Single-storey Extension?
Many homes begin to feel restrictive because the ground-floor layout no longer suits the people living there.
You may need:
- A larger kitchen
- More dining space
- Better family living areas
- Additional storage
- A utility room
- A dedicated workspace
- Better garden access
- More natural light
A single-storey extension can provide this space while also creating the opportunity to improve the rest of the ground floor.
Rather than designing the new room in isolation, we look at how it can change the relationship between the existing spaces.
Single-storey Extensions
Rear Single-storey Extensions
Rear extensions are one of the most common forms of single-storey extension.
They extend the house into the rear garden and can be particularly effective for creating:
- Larger kitchens
- Kitchen-dining rooms
- Family spaces
- Garden rooms
- Utility areas
- Improved garden access
The depth of the extension needs to be carefully considered.
Adding more floor area is not always better if it significantly reduces the garden or makes the original rooms darker.
Good design balances:
- Internal space
- Garden space
- Natural light
- Privacy
- Planning requirements
Side Single-storey Extensions
Where there is unused space beside the property, a side extension can provide valuable additional floor area.
This may be used for:
- Kitchen expansion
- Utility rooms
- Home offices
- Additional living space
- Storage
- Ground-floor bedrooms
- Accessible accommodation
Side extensions need to respond carefully to the width of the plot, neighbouring properties and the appearance of the original house.
Single-storey Kitchen Extensions
A kitchen extension is one of the most common reasons for adding space at ground-floor level.
A new extension can allow you to create:
- A larger kitchen
- Kitchen island
- Dining area
- Family seating
- Better storage
- Utility space
- Larger doors to the garden
- More natural light
The kitchen layout should be considered alongside the architecture.
This means planning:
- Appliance locations
- Storage
- Island position
- Furniture
- Doors
- Windows
- Circulation
- Lighting
Single-storey Extensions
Create a Better Kitchen-dining Space
Many older properties have kitchens and dining rooms separated into individual spaces.
A single-storey extension can create the opportunity to combine them.
This may involve:
- Extending the kitchen
- Removing internal walls
- Widening openings
- Introducing a kitchen island
- Creating space for larger furniture
- Improving access to the garden
The result can be a more connected and practical ground floor.
However, not every home benefits from being completely open plan.
The right layout may include a mixture of connected and separate spaces.
Improving Natural Light
Adding a single-storey extension can change the way natural light reaches the existing house.
This needs to be considered from the beginning.
Natural light can be improved through:
- Rooflights
- Roof lanterns
- Large rear doors
- Glazed side panels
- High-level windows
- Internal glazing
- Wider internal openings
- Carefully positioned windows
The best solution depends on the orientation of the house and the depth of the new extension.
A deeper extension may need more roof glazing to prevent the original rooms behind it from becoming dark.
Single-storey Extensions
Roof Design for Single-storey Extensions
The roof shape affects both the appearance of the extension and the quality of the internal space.
Possible options include:
- Flat roofs
- Pitched roofs
- Mono-pitched roofs
- Hipped roofs
- Roof lanterns
- Rooflights
- Glazed roof sections
The design may be influenced by:
- Existing roof levels
- Window positions above
- Planning restrictions
- Neighbouring properties
- Ceiling height
- Drainage
- Desired architectural style
A simple roof form can often create a cleaner and more successful extension.
Flat Roof or Pitched Roof?
Both flat and pitched roofs can work well.
A flat roof may allow:
- Greater flexibility near first-floor windows
- Cleaner contemporary design
- Easier integration of rooflights
- Lower overall height
A pitched roof may offer:
- Greater internal ceiling height
- A more traditional appearance
- Stronger visual connection to the existing building
The right choice depends on the property rather than one roof type being universally better.
Single-storey Extensions
Connecting the Extension to the Garden
A single-storey extension often changes the relationship between the house and garden.
This can be one of the biggest benefits of the project.
Possible openings include:
- Sliding doors
- Bifold doors
- French doors
- Large picture windows
- Fixed glazing
- Single doors with adjacent glazing
The amount of glazing needs to be considered alongside:
- Heat loss
- Solar gain
- Privacy
- Furniture placement
- Cost
- Orientation
Large glazed openings are not automatically the best solution for every home.
Single-storey Extensions
Connecting the Extension to the Garden
A single-storey extension often changes the relationship between the house and garden.
This can be one of the biggest benefits of the project.
Possible openings include:
- Sliding doors
- Bifold doors
- French doors
- Large picture windows
- Fixed glazing
- Single doors with adjacent glazing
The amount of glazing needs to be considered alongside:
- Heat loss
- Solar gain
- Privacy
- Furniture placement
- Cost
- Orientation
Large glazed openings are not automatically the best solution for every home.
Single-storey Extensions
Structural Changes
Single-storey extensions often involve altering the existing structure.
This may include:
- Removing external walls
- Enlarging existing openings
- Removing internal walls
- Installing beams
- Supporting upper floors
- Creating new foundations
- Supporting new roof structures
Where the new extension opens directly into the existing house, structural calculations are often required.
Foundations for Single-storey Extensions
The foundation design depends on:
- Ground conditions
- Existing foundations
- Nearby trees
- Drainage
- Extension size
- Structural design
Possible foundation solutions may include:
- Traditional strip foundations
- Trench-fill foundations
- Raft foundations
- Engineered foundation systems
The appropriate solution is determined by the site conditions and technical requirements.
Drainage and Services
Extensions can affect existing drainage routes.
Before the design is finalised, it may be necessary to identify:
- Drain locations
- Inspection chambers
- Shared drainage
- Sewer routes
- Water supplies
- tility connections
Drainage can influence where walls and foundations are positioned.
Single-storey Extensions
Do Single-storey Extensions Need Planning Permission?
Not always.
Some single-storey extensions can be built under permitted development rights, provided they remain within the relevant limits and conditions.
Planning permission may be required depending on:
- Extension size
- Depth
- Height
- Position
- Previous additions
- Property type
- Location
- Conservation status
The planning route should be established early.
Planning Permission for Larger Extensions
Where the proposed extension falls outside permitted development rights, a planning application may be required.
Planning authorities may consider:
- Size
- Scale
- Design
- Materials
- Relationship to the original house
- Impact on neighbours
- Overlooking
- Daylight
- Garden space
- Local planning policy
A well-prepared design should respond to these considerations from the beginning.
Single-storey Extensions in Conservation Areas
Additional planning considerations may apply where the property is within a conservation area.
The local authority may pay particular attention to:
- Extension scale
- Materials
- Roof form
- Visibility
- Original building character
- Relationship with neighbouring properties
A contemporary design may still be possible where it responds appropriately to the context.
Building Regulations for Single-storey Extensions
Single-storey extensions need to comply with Building Regulations.
Requirements may include:
- Foundations
- Structural safety
- Insulation
- Ventilation
- Fire safety
- Drainage
- Roof construction
- Glazing
- Electrical work
- Thermal performance
Building Regulations apply separately from planning permission.
A project may not need planning permission but may still require Building Regulations approval.
Single-storey Extensions
Single-storey vs Double-storey Extension
A single-storey extension adds space only at ground-floor level.
A double-storey extension can provide additional accommodation on both the ground and first floors.
A single-storey extension may be more suitable when you need:
- A larger kitchen
- More living space
- A utility room
- Better garden access
- Ground-floor workspace
- As part of a wider renovation project
A double-storey extension may make more sense where you also need:
- Additional bedrooms
- Extra bathrooms
- First-floor storage
- More substantial overall accommodation
Single-storey vs Wraparound Extension
A single-storey extension describes the number of floors rather than a specific footprint.
It can therefore include rear, side or wraparound designs.
A wraparound extension usually combines rear and side additions to create a larger L-shaped footprint.
If the property has both a side return and sufficient garden space, a wraparound extension may offer more flexibility.
Single-storey Extensions
Materials for Single-storey Extensions
The extension can either blend with the existing property or create a deliberate contrast.
Possible materials include:
- Matching brickwork
- Contrasting brick
- Render
- Timber cladding
- Metal cladding
- Stone
- Large areas of glazing
The material choice should consider:
- Existing architecture
- Planning context
- Maintenance
- Budget
- Desired appearance
A simple material palette often produces the strongest result.
Single-storey Extensions
Single-storey Extension Process
1. Understand What You Need
We begin by discussing:
- The existing house
- The problems with the current layout
- The space you need
- Your priorities
- Your budget
- Your long-term plans
2. Explore the Options
We consider:
- Extension position
- Size
- Layout
- Internal wall changes
- Garden relationship
- Natural light
3. Develop the Design
The preferred option is then developed in greater detail.
This includes:
- Roof form
- Windows
- Doors
- Materials
- Internal layout
4. Obtain Approvals
Where required, this may include:
- Planning permission
- Permitted development confirmation
- Building Regulations
- Structural calculations
5. Prepare for Construction
Technical drawings can then be prepared for pricing and construction.
Client experience
"
Lorem ipsum dolor sit amet, consectetur adipiscing elit. We had a vision for our home but no idea how to realise it. Tholos Interiors took complete ownership of the project — every detail was considered, every decision explained. The result exceeded everything we had imagined.
– Lawrence Ipsum, Homeowner · London –
Frequently Asked Questions
How big can a single-storey extension be?
The possible size depends on the property, available land, planning rules and whether the extension falls under permitted development or requires planning permission.
Can a single-storey extension include a kitchen and dining area?
Yes.
Kitchen-dining spaces are one of the most common uses for single-storey extensions.
Will an extension make the existing house darker?
It can if daylight is not planned carefully.
Rooflights, larger openings and well-positioned glazing can help bring light into both the extension and the existing property.
Do I need Building Regulations approval?
Usually, yes.
A new extension will generally need to comply with Building Regulations even where planning permission is not required.
Do I need Building Regulations approval?
Usually, yes.
A new extension will generally need to comply with Building Regulations even where planning permission is not required.
Create Space That Improves the Whole Home
A single-storey extension can provide much-needed additional space, but its biggest value often comes from what it allows you to do with the existing house.
A carefully designed extension can improve the kitchen, circulation, natural light, garden connection and overall ground-floor layout at the same time.
At Tholos Architects, we can help you develop the design and prepare the drawings required to take the project forward.
Disclaimer
This article is part of a series created by our dynamic marketing team for informational purposes only. While we strive to review all content thoroughly, occasional oversights may occur, even after publication. Therefore, we cannot accept liability for any interpretations or use of the information provided. For the most up-to-date information or to report any discrepancies, please contact us at hello@tholos-architects.com.
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