Single Storey Extension – Winstanley

#HomeExtension #BuildingRegulations #WiganArchitecture #MelroseDesigns #SideExtension #SmartLiving #HomeUpgrade

At Melrose Designs, we take pride in helping homeowners transform their living spaces into something more practical, stylish, and energy-efficient. One of our latest projects in Wigan is a great example of how a well-designed single-storey side extension can add both form and function to a family home.

In this blog post, we’ll walk you through what we delivered on this exciting project — from compliance with building regulations to sustainable insulation choices — all while keeping our client’s lifestyle and budget in mind.

The Brief

Our client, approached us looking to add more usable living space to his property without altering the character of the existing home. The goal was to create a practical and attractive side extension that would provide room for a new office and a more open family area, while maintaining access, privacy, and efficient drainage.

We were happy to take on the job, offering a full Building Regulations drawing package tailored to suit the needs of the property — and the local authority’s requirements in Greater Manchester.

Functional Design That Blends In

When adding to an existing property, especially in a suburban setting like Wigan, it’s essential to design something that doesn’t just function well, but also looks like it’s always belonged there. We designed a side extension that seamlessly integrates with the original home’s aesthetics by using matching reclaimed brickwork and white UPVC windows to maintain visual consistency.

To complement the rear of the house, we included French doors and a generous glazed window, allowing plenty of natural light to flow into the newly formed internal spaces.

Built to Last – Structure and Materials

For the structure, we specified 100mm blockwork internal walls, full cavity insulation, and C24 timber rafters, all to modern structural standards. With a 15° pitched roof, we used Marley Mendip interlocking concrete tiles to blend with the existing roofscape.

To ensure longevity and minimal maintenance, we included high-quality cavity closures, stainless steel wall ties, birdsmouth cut rafters, and UPVC fascia, soffits, and gutters. The roof build-up achieved excellent thermal performance with Celotex XR4000 and Kingspan Thermapitch insulation, providing year-round comfort and energy efficiency.

Meeting and Exceeding Building Regulations

Our Building Regulations drawings ensured compliance with Part A (structure), Part L (conservation of fuel and power), and Part C (resistance to contaminants and moisture), among others. Key features included:

- 130mm PIR insulation between rafters for optimal thermal performance

- Fire-rated elements offering a minimum 30-minute resistance

- Safety glazing below 800mm in accordance with BS 6206

- Background and trickle ventilation to all habitable rooms

- Roof and wall U-values that beat the latest energy efficiency targets

We also made sure all new cavities were continuous, cold bridging was minimised, and cavity trays with weep holes were positioned correctly above all external openings.

Efficient Drainage and Heating

As with all projects, (Single Storey Extension – Winstanley)

ensuring effective drainage is a priority. We assumed a separate existing system and proposed new 100mm UPVC pipework laid to a 1:40 fall, encased in concrete, and connected via new back-inlet gullies.

Heating-wise, we coordinated with the client’s Gas Safe installer to ensure the extended space could be seamlessly integrated with the existing central heating system, with radiators on TRVs for room-by-room control.

A Great Result for a Growing Home

The completed design added a practical and light-filled extension that gave our client more flexibility in how they use their home — whether as a workspace, playroom, or future guest room. The new layout supports modern family living while ensuring full compliance with local regulations and sustainable building practices.

Thinking of Extending Your Home?

Whether you’re planning a rear kitchen extension, a side office room, or a full wraparound design, Melrose Designs can help bring your vision to life. We offer a friendly, professional service backed by years of experience across Wigan, St Helens, and the wider North West.

If you’d like to talk about your project, get in touch with us today. We’re happy to offer a free consultation to explore what’s possible with your home.