Two‑Storey Side Extension Belfast – A Gorgeous Transformation in Gilnahirk

A Project Close to Home in Gilnahirk

Some projects feel special from the very beginning — and this one certainly did. Gilnahirk is where I grew up, went to school, and first discovered my interest in architectural design. Returning years later to deliver a two‑storey side extension Belfast project in the very streets I know so well was a genuine pleasure.

My clients, Mr and Mrs C, wanted to remove their old attached garage and replace it with a modern, spacious two‑storey extension that blended seamlessly with their beautiful detached home. They needed more space, better flow, and a layout that supported everyday family life. This project delivered all of that and more.

The new two‑storey side extension in Gilnahirk blends perfectly with the original home — matching brickwork, roof tiles, and window proportions for a seamless finish.

Before & After – A True Home Transformation

Before the extension, the home had a traditional layout: smaller rooms, limited natural light, and a garage that no longer served a useful purpose. The kitchen was enclosed, the dining room felt separate, and the upstairs bedrooms needed more breathing room.

After the extension, the difference is remarkable. The new open‑plan kitchen, dining, and family room has become the heart of the home — bright, sociable, and perfect for everyday living. Upstairs, the enlarged bedrooms and redesigned bathroom have completely changed how the home feels. It’s now a modern, spacious family home with a layout that works beautifully.

The existing entrance showing new extension to the right with floor to ceiling window in the kitchen area

⭐⭐⭐⭐⭐ Client Feedback – 5 Stars on Google

“Glenn provided us with a fantastic service, thanks to his expertise and efficiency we had planning permission granted within a matter of weeks after submitting plans for our two story side extension & renovation. It was a pleasure to work with Glenn and we would strongly recommend GT Building Design. Thank you very much, Charles.”

The new open‑plan sitting room connects effortlessly to the garden, flooding the space with natural light and creating a calm, modern atmosphere — a hallmark of this Gilnahirk two‑storey side extension

Two‑Storey Side Extension Belfast – Designed to Match the Existing Home

The approved planning drawings set out a clear and carefully considered design. The proposed finishes were selected to ensure the extension looked like it had always been part of the original home:

“Walls: Red clay facing brick… Windows & External Doors: White upvc frames… Roof Tiles: Profiled concrete.”

This attention to detail meant the new structure complemented the existing architecture perfectly — a key requirement for any successful two‑storey side extension Belfast project.

Both Planning Permission and Building Control Approval were secured smoothly, allowing the build to progress without delay.

The open‑plan living area showcases the seamless flow between kitchen, lounge, and garden — a bright, modern space created through the Gilnahirk two‑storey side extension

What I Delivered

This project included a full package of design, planning, and technical improvements:

• Planning Permission secured

• Building Control approval achieved

• Full two‑storey side extension

• Open‑plan kitchen, dining, and family room

• Enlarged first‑floor bedrooms

• Modernised bathroom layout

• Improved circulation and natural light

• Matching external finishes for seamless integration

The new kitchen and dining area combines clean lines, modern materials, and natural light — a stylish, functional space at the heart of this Gilnahirk two‑storey side extension

Client Wish List – Practical, Modern, and Family‑Focused

Ground Floor Improvements

• Convert the cloakroom under the stairs into a WC

• Block up the existing back door and internal kitchen door

• Enlarge the hallway opening into the dining room

• Demolish the existing garage

• Build a full two‑storey side extension to create a bright open‑plan kitchen, dining, and family room

First Floor Enhancements

• Extend two existing bedrooms into the new structure

• Remove the partition wall to create one large bathroom with a separate shower

• Relocate the gas boiler into the attic

The open‑plan kitchen and living area is flooded with natural daylight, offering effortless access to the garden — a bright, welcoming space at the heart of this home.

Professional Insight – Designing Extensions That Truly Belong

Two‑storey side extensions often require careful attention to matching brickwork, roof pitches, and window proportions. Getting these details right ensures the extension blends seamlessly with the existing home — and helps Planning approval progress smoothly.

In this case, the elevations in the approved drawing highlight how carefully the extension was integrated:

• Matching brickwork

• Matching roof tiles

• Matching rainwater goods

• Matching White uPVC windows

• Matching Black uPVC fascias and rainwater goods

These details ensured the extension felt natural and cohesive — a hallmark of a well‑executed two‑storey side extension Belfast project.

The superb new kitchen combines sleek white cabinetry, grey worktops, and a minimalist layout — a bright, functional space that completes this extension beautifully

Is a Two‑Storey Side Extension Right for Your Home?

For many homeowners, a two‑storey side extension is one of the most cost‑effective ways to add significant space without moving house. It can provide:

• A larger kitchen or open‑plan living area

• Additional bedroom space

• A more modern bathroom layout

• Better natural light

• Improved flow and functionality

  
  

If your home feels tight, dated, or no longer suits your lifestyle, a well‑designed extension can completely transform how you live.

The open‑plan kitchen and dining area connects beautifully to the garden, combining modern design with bright natural light — a standout feature of this side extension

Local Expertise Matters

Having grown up in Gilnahirk, I understand the character of Belfast homes — and how to design extensions that respect the area’s architectural style. This local knowledge helps ensure your project blends beautifully with the neighbourhood and progresses smoothly through Planning.

The redesigned family bathroom combines a freestanding bath, walk‑in shower, and contemporary finishes — a spacious, elegant retreat created.

The new family bathroom feels spacious and luxurious — the old separate WC was removed to create one elegant, open space with walk‑in shower and freestanding bath

The new double bedroom feels bright and spacious — the opening through the existing wall connects seamlessly into the extension, creating a calm, modern retreat with garden views.

A True Gilnahirk Success Story

This project combined thoughtful design, efficient planning, and a strong client relationship. The finished home is brighter, more spacious, and perfectly suited to modern family living. It’s a transformation I’m proud of — especially in a place that means so much to me personally.

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Why Choose GT Building Design

With over 40 years’ experience in residential design, I help homeowners plan extensions, conversions and internal alterations with clear drawings, practical guidance and a smooth, well‑managed process from first ideas through to approval.

I work with homeowners across North Down, Greater Belfast and the surrounding towns, supporting a wide range of projects — from small internal changes to full house extensions and larger home improvements.

You can explore my services below:

• House Extensions  

• Loft Conversions  

• Garage Conversions  

• Internal Alterations

  
  

If you’re planning a home extension or thinking about improving your layout, you’re welcome to get in touch and talk through your ideas. A calm, practical chat at the start can often make the whole process much easier.

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Frequently Asked Questions – Two‑Storey Side Extension Belfast

1. How long does it take to get Planning Permission for a two‑storey side extension in Belfast?

Most two‑storey side extensions in Belfast take 12 weeks for Planning Permission, depending on the complexity of the design and the council’s workload. In this Gilnahirk project, approval was granted within a matter of weeks, thanks to a well‑prepared application and a design that respected the existing home and streetscape.

2. Will a two‑storey side extension blend in with my existing home?

Yes — when designed correctly. Matching brickwork, roof pitches, window proportions, and external finishes ensures the extension looks like it has always been part of the house. In this project, we used red clay facing brick, white uPVC windows, and profiled concrete roof tiles to achieve a seamless finish.

3. What rooms can I add with a two‑storey side extension Belfast?

A two‑storey side extension typically allows you to add:

• A large open‑plan kitchen/dining/family room

• A utility or WC on the ground floor

• Bigger bedrooms upstairs

• A modern bathroom layout

  
  

  This Gilnahirk home gained all of these improvements, transforming how the family uses their space every day.

4. Do I need Building Control approval as well as Planning Permission?

Yes — both are required. Planning Permission deals with the appearance and impact of the extension, while Building Control ensures the structure is safe, insulated, fire‑compliant, and built correctly. This project secured both approvals, allowing construction to proceed smoothly.

5. Is a two‑storey side extension better value than moving house?

For many families, absolutely. A two‑storey side extension can add significant space at a lower cost than buying a larger home — especially in areas like Belfast where demand is high. It also lets you stay in the neighbourhood you love while upgrading your home to suit modern living.

6. How do I know if my home is suitable for a two‑storey side extension?

Many detached and semi‑detached homes in Belfast can accommodate a side extension, provided there is enough space at the side and the design respects the existing architecture. A quick site assessment will confirm feasibility. In this case, removing the old garage created the perfect footprint for a spacious two‑storey extension.