Whether you're adding space for a growing family or increasing the value of your home, this free guide walks you through everything you need to know about designing and building a house extension, without the stress. Get the expert-written PDF, plus access to our step-by-step video series delivered to your inbox over the coming weeks!
We’ve worked with thousands of homeowners across the UK, and we know the biggest stress isn’t always the build, it’s not knowing what comes next.
This guide is designed to remove that uncertainty. It’s the advice we give every new client, pulled into one easy-to-follow resource.
We know this might be your first extension. That’s why, alongside the guide, we’re releasing a step-by-step video series designed to help you navigate the process with confidence.
Each video builds on the last, breaking down key stages and offering practical tips to support your project from start to finish.
At the back of the guide, you’ll find details of free tools and services we offer to help you move forward, like Q Spec (our quantity surveying service) and Design Spec Connect (our builder-matching service).
You’re under no obligation to use them, but they’re here if you need them.
Get a look behind the scenes of a real Design Spec project, from first sketch to final sign-off. See how Sophie and Matt went from cramped kitchen to open-plan living space, all within budget.
“We had £100k to spend. Their team designed to £95k. The builder’s quote came in at £97k. Couldn’t have asked for better.”
— Sophie & Matt, Romford
We’ll send your free home extension guide straight to your inbox, packed with clear, practical advice to help you plan with confidence. You’ll also get access to our exclusive weekly video series, created to walk you through the key steps of extending your home, from planning permission to managing budgets and avoiding common pitfalls.
Just fill out the form to get instant access. Whether you’re just starting to explore your options or ready to take the next step, our expert guidance will help you understand everything you need to know about home extensions in the UK.
Once you download the guide, you’ll be better equipped to make decisions, ask the right questions, and avoid the most common mistakes that cost UK homeowners time and money during home extension projects.
We offer a free 30-minute consultation call. It's a chance to talk to an experienced member of our team about your ideas and what might be possible. Whether you're weighing up your options or ready to start, we'll help you take those first steps with confidence.
And once you've downloaded the guide, we'll also send you a weekly video, short, practical, and focused on different stages of the home extension journey. Together, we will help you move forward without the guesswork.
No. This home extension guide is designed to help homeowners at every stage of the process. Whether you’re just beginning to explore ideas or already speaking to designers or builders, the guide provides practical, jargon-free advice to help you move forward with clarity.
It’s ideal if you’re planning a house extension in the UK but aren’t sure what to expect, what’s possible within your budget, or what steps come first.
Yes. A key feature of the guide is a comprehensive breakdown of house extension costs in the UK, with typical price ranges per square metre for different types of extensions, including single-storey rear extensions, loft conversions, and full renovations.
It also explains where your budget actually goes, from structural work to finishes, and includes advice on setting a realistic contingency. If you’re budgeting for a house extension, this guide will help you plan with much greater accuracy.
Absolutely. One of the most valuable parts of the guide is the section that explains planning permission for house extensions in the UK.
It covers the difference between planning approval and building control, what drawings are required at each stage, and how to avoid common reasons for rejection. If you’re unsure whether your extension needs permission, or want to boost your chances of approval, this guide is essential reading.
Yes. The guide outlines the pros and cons of different types of house extensions, from rear and side extensions to loft conversions and two-storey builds.
It also includes advice on which type suits which kind of home and lifestyle. Whether you're looking to open up your kitchen, create a home office or add an extra bedroom, this guide helps you assess your goals and choose the right kind of house extension for your needs.
We ask for your email so we can send you the guide instantly, and follow up with a short series of helpful, non-salesy emails over the next 2–3 months.
These emails are designed to support you through the early planning stages, with extra tips, reminders, and advice that build on the content of the guide. You can unsubscribe at any time, and we will never share your data.