Extension & Loft Conversion Specialists – Free Architectural Plans Included

Maximise your space. Enhance your home. One seamless, all-inclusive service.

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At ASG, we’re experts in transforming homes with high-quality extensions and loft conversions. Whether you're looking to expand your living area, add an extra bedroom, or create a stunning open-plan kitchen, we handle every detail from start to finish — including professional architectural plans at no extra cost. With us, there are no hidden fees — just beautifully designed, expertly built spaces delivered on time and within budget.

About Us

Your Trusted Partner for Home Transformation

With over 15 years of experience in residential construction, ASG has earned a reputation for delivering high-standard loft conversions and home extensions across Hertfordshire. Our team of skilled builders, project managers, and in-house designers work closely with you to turn unused space into beautiful, functional living areas.

We simplify the process with a full design & build service — and we include architectural drawings completely free as part of your package, saving you time and money from the start.

Our Services

Loft Conversions

Unlock the potential in your attic. Our loft conversions add value, light, and space to your home, with options including:

Dormer Conversions

Mansard Conversions

Hip-to-Gable Conversions

Velux (Rooflight) Conversions

En-suite Additions

Home Extensions

Need more room? We create bespoke home extensions tailored to your lifestyle:

Single-Storey Extensions

Rear & Side Return Extensions

Double-Storey Extensions

Open-Plan Kitchen/Diner Extensions

Garage Conversions

What’s Included in Every Package:

FREE Architectural Drawings & Floor Plans

Planning Permission Support (if required)

Full Project Management

Building Control Compliance

High-Quality Materials & Workmanship

Fixed Price Quote – No Surprises

Why Choose Us

  • All-Inclusive Packages: Free architectural plans, construction, and management — all under one roof
  • Tailored Solutions: Every project is custom-designed to suit your home, needs, and budget
  • End-to-End Service: We manage everything from initial survey to final sign-off
  • Qualified & Experienced Team: Fully insured, accredited, and passionate about quality
  • Transparent Pricing: Fixed quotes with no hidden extras
  • Local Experts: Trusted by homeowners across Hertfordshire.

Our Process

Free Site Visit & Consultation

We assess your space and discuss your ideas.

Free Architectural Plans

Our in-house designers create detailed drawings to bring your vision to life.

Planning & Permissions

We handle planning applications and liaise with building control if required.

Construction & Project Management

Our skilled builders get to work, with a dedicated manager keeping you updated.

Completion & Handover

We walk you through your new space

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