Extension drawings
Extending your home can be a transformative way to add space, functionality, and value—without the upheaval of moving. Whether it’s a growing family, a need for a home office, or a desire for more open-plan living, a home extension offers a tailored solution. But with multiple options, legal considerations, and design choices, it’s important to understand what’s involved before starting.
Benefits of Extending Your Home
• Increased living space
• Enhanced property value
• More functional layout
• Avoids the cost and hassle of moving
• Customised to your needs and lifestyle
Types of Home Extensions in the UK
1. Rear Extension
Description: Built at the back of a property, rear extensions are ideal for expanding kitchen-diners, creating family rooms, or adding utility spaces.
Best For:
• Open-plan living
• Properties with large gardens
• Semi-detached or detached homes
Typical Size:
• Up to 3–6 metres under permitted development, depending on property type and location.
Planning Note:
• Often falls under permitted development (PD) if within size limits and not in a conservation area.
2. Side Return Extension
Description: Utilises the narrow alley or “dead space” at the side of a property, commonly found in Victorian or Edwardian terraces.
Best For:
• Enlarging a kitchen or dining area
• Creating a more spacious, light-filled rear layout
Design Tips:
• Incorporate roof glazing to avoid dark interiors
• Combine with a rear extension for a wraparound design
Planning Note:
• May be allowed under PD if within certain size and height limits.
3. Wraparound Extension
Description: A combination of rear and side return extensions that form an “L” shape. These maximise footprint and often enable complete ground floor reconfiguration.
Best For:
• Large open-plan living, kitchen, and dining areas
• Homes needing layout transformation
Planning Note:
• Usually requires full planning permission due to increased size and impact on neighbours.
4. Double-Storey Extension
Description: Adds extra space both on the ground and first floor, significantly increasing square footage and functionality.
Best For:
• Adding bedrooms and bathrooms
• Larger families or home-based businesses
Planning Note:
• Not permitted under PD if it extends more than 3m from the rear wall.
• Requires careful consideration of neighbour impact and aesthetics.
5. Loft Conversion
Description: Converts the existing attic space into habitable rooms—often a bedroom, office, or bathroom.
Types:
• Dormer (adds vertical walls and flat roof)
• Hip-to-Gable (extends sloping roof to create vertical gable)
• Mansard (steeper rear slope for maximum space)
Planning Note:
• Many loft conversions are permitted developments, but mansards usually require full planning.
6. Garage Conversion
Description: Turns an integral or detached garage into a habitable room—often used as an office, playroom, or spare bedroom.
Benefits:
• Cost-effective
• Minimal disruption to main structure
Planning Note:
• Often allowed under permitted development, but check if planning permission was originally required to build the garage.
7. Basement or Cellar Conversion
Description: Converts or creates an underground level. Offers significant extra space but is more complex.
Best For:
• Urban properties with limited external space
• High-value areas like London
Considerations:
• Structural complexity
• Waterproofing
• Light and ventilation
• High cost
Planning Note:
• Almost always requires planning permission and Building Regulations approval.
Planning Permission vs. Permitted Development
Permitted Development (PD) Rights
PD rights allow certain types of extensions without formal planning permission, provided they meet strict criteria on:
• Size and height
• Distance from boundaries
• Materials used
• Roof design
• No adverse impact on neighbours
PD rules differ for:
• Flats, maisonettes, and listed buildings (not eligible)
• Conservation areas or AONBs (stricter limits)
When Planning Permission is Required
• Exceeding PD limits
• Wraparound or double-storey extensions
• Design changes affecting streetscape
• Listed buildings or conservation areas
Tip: Always apply for a Lawful Development Certificate (LDC) even if using PD to avoid disputes later.
Building Regulations
Regardless of whether planning permission is needed, all extensions must comply with Building Regulations, covering:
• Structural integrity (foundations, walls, roofs)
• Fire safety and escape routes
• Thermal efficiency (insulation and glazing)
• Sound insulation
• Drainage and ventilation
• Electrical and plumbing safety
You can apply via:
• Full Plans Application (recommended for complex works)
• Building Notice (quicker for simple domestic works)
An approved inspector or your local authority’s Building Control team will inspect the work at key stages.
Cost of Home Extensions in the UK (2025 Estimates)
Rear Extension (Single): £1,800 - £2,500 per sqm
Side Return Extension: £2,000 - £2,700 per sqm
Wraparound Extension: £2,200 - £3,200 per sqm
Double-Storey Extension: £2,200 - £2,800 per sqm (lower floor higher)
Loft Conversion (Dormer): £40,000 - £60,000+
Garage Conversion: £10,000 - £25,000
Basement Conversion: £3,000 - £4,500 per m
Factors Affecting Cost:
• Location (London premiums)
• Access and site conditions
• Structural alterations
• Finish level (basic vs high-end)
• Professional fees (architects, engineers, planners)
Professional Services You May Need
• Architectural Designer – Design and planning drawings
• Structural Engineer – Load-bearing assessments and calculations
• Planning Consultant – Help with complex or contentious applications
• Quantity Surveyor – Cost planning and budget control
• Builder / Main Contractor – Construction and site management
• Party Wall Surveyor – If works impact shared walls
Key Considerations for a Successful Home Extension
1. Define Your Needs Clearly
• What space do you need and why? How will you use it?
2. Understand Legal Constraints
• Are you in a conservation area? Do you need planning permission?
3. Set a Realistic Budget
• Include contingency (10–15%) and professional fees.
4. Choose the Right Team
• Go with experienced professionals with local knowledge.
5. Think About the Future
• Will your extension add value? Meet future lifestyle changes?
6. Minimise Disruption
• Plan for temporary living arrangements or phased works.
Conclusion
Home extensions in the offer an excellent way to increase space, tailor your living environment, and add long-term value to your property. Whether it’s a modest side return or a full-scale double-storey extension, success lies in careful planning, compliance with regulations, and working with Draw and Plan. With the right approach, your dream extension can become a seamless, rewarding investment in your home and lifestyle.