🔧 Architects, Meet Your New Favourite Desk Companion.

House Extension Details is packed with the technical knowledge and construction drawings you need to get the job done—accurately, efficiently, and without reinventing the wheel (again).

Created by architectural professionals for architectural professionals, this guide focuses on what matters most—technical clarity, real-world applicability, and time-saving resources you can trust. Whether you're a sole practitioner juggling multiple roles or part of a small studio delivering bespoke domestic extensions, this book equips you with the tools to work smarter and with greater confidence.

📐 What You’ll Get

• A comprehensive library of 200+ 2D construction details: walls, foundations, floors, roofs, thresholds, doors, windows, rooflights and more
• Multiple build-ups including timber frame, masonry cavity, solid wall retrofits, and structural glazing detailing strategies
• Clear annotation and practical context for how and when to apply each detail
• CAD and SketchUp files available in bundled formats for seamless integration into your workflows
• Example planning and technical drawing packs
• Real-life project guidance, including regulatory considerations, material selection, and detail design tips

🛠️ Designed For

• Sole traders and small practices needing reliable detailing references
• Architects looking to streamline technical design stages without compromising quality
• Young architects looking to broaden their construction detailing knowledge

This book isn’t just a collection of drawings—it’s a working reference designed to support the realities of architectural practice. Save time on every project, enhance design quality, and gain confidence in your detailing decisions.

See the Book for Yourself – Download a Free Sample

Curious about what's inside? We’re offering a free sample of House Extension Details: An Architectural Guide so you can experience the quality and depth of content first-hand.

Inside the sample, you’ll find practical examples, expert construction details, and a full index of the 200+ details inside.

Discover why architects will be calling this an essential reference for house extensions.

💥 Here’s What Makes It Awesome

This isn’t a dusty textbook or a vague “design inspiration” guide. It’s a real-world tool for real-world architects.

You’ll get clear drawings, smart commentary, and loads of guidance to help you create extensions that work—structurally, aesthetically, and thermally.

We’ve even included multiple insulation strategies, cavity options, and material pairings—so you’re covered whether you’re working on a dreamy garden studio or a challenging retrofit on a semi with five previous owners and no straight lines.

Choose the Right Bundle for You

👉 We’ve created three flexible bundles to suit the way you work — whether you want quick inspiration or a full set of resources to power your next project. Select your bundle and get started today. 

Digital copies not permitted for purchase by universities, libraries or institutions. Please click here to find out more.

🙌  Praise for the Book 

Encyclopaedic in its depth and completely unique and comprehensive. It should be an ally to any architectural designer - student or experienced professional. This is the best piece of architectural writing I've seen, if only I had this a decade ago throughout my university years - a lot of mistakes would've been avoided. Incredible work.

Liam Briggs - Chartered Architectural Technologist

A clear, beautifully presented technical resource and an invaluable reference for designers working in residential settings. It's accessible at all levels - starting from first principles and expanding into detailed design thinking through the chapters. A fantastic, comprehensive guide - truly an extension bible!

Sonia Brookes - Architect

The book's thoroughness is truly impressive. Each detail is carefully broken down with clear explanations, well-cited sources and visually compelling 3D illustrations. It succeeds in taking a complex subject and presenting it in a format that is both accessible and easy to understand.

Joe Hyett - Chartered Architectural Technologist

Wow, what a great book for the UK market! This is the best book for anyone struggling to understand extensions. Well done guys, you nailed it.

Sonda Mvula - Architectural Designer and Director

Meet the Authors

Emma Walshaw

Emma is the founder of First In Architecture and author of several construction detailing books. Emma has spent years helping architecture students and professionals deepen their understanding of construction detailing. Her work is driven by a desire to make complex information accessible and to support others in their learning journey.

In this collaboration with Aida, she continues her mission to provide architects with the tools they need to produce detailed, effective designs.

Aida Rodriguez Vega

Aida is an experienced architect with a strong background in technical detailing and high end residential projects. Drawing from her practical experience, Aida brings a comprehensive and meticulous approach to the content in this book.

She is passionate about bridging the gap between theoretical knowledge and real-world application, and has worked closely with Emma to develop a resource that is both informative and immediately useful for anyone working on house extensions.

Emma's Books Have Been Featured In

Frequently Asked Questions

*PLEASE NOTE: If you are a university, institution, or library, the digital books are not permitted for purchase. You can purchase hard copies by clicking the link above, or you can check out the other options available using this link. Alternatively, feel free to contact our team at hello@firstinarchitecture.co.uk to discuss available options in more detail.