TWELVE CONSTRUCTION LTD

At Twelve Design & Build, we specialize in transforming homes across London, Surrey, and Sussex with carefully managed extensions, loft conversions, and full refurbishments.

Whether you’re looking to create more space for a growing family, unlock the potential in your loft, or modernize your entire property, we bring precision, care, and creativity to every project.

Our Story

We’re not your typical building company.

Twelve was founded when two airline pilots partnered with a highly experienced builder to deliver property projects with a difference.

We combined aviation’s attention to detail, planning, and reliability with hands-on building expertise – creating a team that homeowners can trust.

That background has shaped the way we run projects today: structured, transparent, and always focused on safety, quality, and efficiency.

What We Do

We take on a wide range of residential building works, including:

• Home extensions – wraparound, rear, side return and single-storey extensions
• Loft conversions – dormer, hip-to-gable, mansard, rooflight conversions, with en-suites or home offices
• Full refurbishments – from kitchens and bathrooms to complete internal reconfigurations
• Structural works – wall removals, RSJs, propping and steels installed to engineer’s specifications
• Garden rooms and landscaping – creating outdoor spaces that flow with your home

We manage projects from start to finish, handling drawings, planning, building control, and the build itself.

How We Work

Building projects can feel daunting – but they don’t have to. Our approach makes the process straightforward and stress-free:

• Clear communication – we keep you updated at every stage
• Transparency – no hidden costs, fully itemised quotes, fixed prices once designs are finalised
• Project management – we coordinate trades, suppliers, and inspectors so you don’t have to
• Clean and considerate sites – we respect your home and your neighbours
• Local knowledge – we’ve completed projects across Wandsworth, South London, Surrey, and Brighton & Hove

Why Choose Us

• Experienced in delivering complex residential builds
• Fully insured, with work carried out to building regulations and structural engineer specifications
• Trusted team of trades and specialists we’ve worked with for years
• Strong track record of completing projects on time and within agreed budgets
• A personal, approachable service we treat every project as if it were our own home

Our Promise

We know choosing a builder is a big decision.

That’s why we promise to be transparent, reliable, and committed to quality from day one.

Our clients often tell us they appreciate the peace of mind that comes from knowing their project is in safe hands.

If you’re planning a loft conversion, extension, or refurbishment, we’d love to hear about your ideas.

Get in touch today to arrange a friendly consultation we’ll help you explore your options, get a clear understanding of costs, and make the most of your home.