A well-designed extension can be life-changing—and if you’re searching for single storey extension ideas for semi detached house, you’re in the right place. At KT5 Construction, we’ve helped homeowners across London and Surrey unlock their home’s potential with smart, cost-effective designs that blend style, function, and value. Whether you’re looking to expand your kitchen, create a family hub, or open up your garden view, here are some inspirational ideas backed by expert guidance.

Why Choose a Single Storey Extension for a Semi-Detached House?

Single storey extensions are ideal for semi-detached homes thanks to their flexibility and affordability. You can build outwards without drastically altering the home’s structure—perfect if you want more space without the cost of moving.

Key Benefits

• • Adds up to 20% property valueSemi-detached house ext…

  • Typically more affordable than double-storey builds

  • Quick turnaround times

  • Minimal disruption to existing living areas

  • Great for open-plan kitchen-diner layouts

10 Single Storey Extension Ideas For Semi-detached House

1. Rear Kitchen-Diner Extension

A full-width rear extension can turn a cramped kitchen into a stunning, light-filled family space. Incorporate bi-fold doors and a roof lantern to create a seamless indoor-outdoor flow.

2. Side Return Expansion

Use the narrow alley along the side of your property to extend the kitchen or dining area. This “side return” design is especially effective in older Victorian or Edwardian semis.

💡 Top Tip: Opt for skylights or Velux windows to keep light levels high.

3. L-Shaped Wraparound

Combine a rear and side return extension to create an L-shaped layout. This adds serious square footage and creates space for a larger kitchen, utility room, or even a home office.

4. Glass Box Extension

Let natural light flood your space with a contemporary glazed extension. Popular in London builds, glass boxes blur the boundary between your home and garden.

🔨 KT5 Construction uses energy-efficient glazing for sustainability and comfort.

5. Open Plan Family Room

Transform your ground floor with a large multi-purpose space for cooking, lounging, and entertaining. Add sliding doors for garden access and zoned lighting for evening ambience.

6. Small But Smart

On a tight budget or short on space? Even a 2-3 metre extension can make a big difference. Prioritise layout and storage to make every square metre count10 Semi Detached Extens….

7. Utility and Boot Room Add-On

Use a modest extension to add a practical space for laundry, pet care or muddy boots. This can declutter your main living space and boost resale appeal.

8. Home Office Nook

As hybrid work becomes the norm, a rear or side extension makes the perfect quiet zone for productivity. Built-in desks and natural light are a must.

9. Modern Flat Roof Design

A flat roof keeps the build discreet and often reduces planning hassle. KT5’s design team can incorporate hidden drainage and insulation for year-round comfort.

10. Feature Rooflines and Skylights

Create architectural interest with pitched or asymmetric roof shapes. This not only boosts visual appeal but enhances ceiling height and natural light.

Planning and Permission Essentials

Under Permitted Development, most single storey extensions up to 3m (or 6m with prior approval) don’t require full planning permission. However, KT5 always helps homeowners confirm:

• • Whether your design meets local planning regulations

  • If Party Wall agreements are required

  • Whether building control sign-off is needed

📌 Note: Rules may vary by borough—especially in conservation areasSemi-detached house ext….

Materials That Match Your Home

KT5 Construction offers a range of materials to suit your style and budget:

• • Brickwork: Seamlessly blend with your original home

  • Timber cladding: A rustic or Scandi-style look

  • Glass and steel: Sleek, modern finishes for bold extensions

  • Green roofs: Eco-conscious and great for insulation

Cost Considerations

Single storey extensions typically cost between £1,500 and £3,500 per m², depending on materials and locationSemi-detached house ext…. As your trusted London builder, KT5 offers:

• • Transparent pricing

  • Cost-saving design tweaks

  • Optional phased works to suit your budget

📌 Prices may differ based on location and type of project.

Why Homeowners Choose KT5 Construction

KT5 is the go-to builder in London and Surrey for high-quality, stress-free extensions. We offer:

• • Planning support
  • Structural engineering advice
  • Fixed-fee architectural design
  • Project management from start to finish

We help you avoid costly mistakes and get the most value from your investment—whether that’s boosting floor space, increasing home value or improving day-to-day living.

Ready to Expand Your Home?

Take the first step towards your dream extension. At KT5 Construction, we’ll help you bring your vision to life—on time and on budget.

📩 Email Us Your Requirements Now or
📅 Book a Consultation with Our Experts