Common House Extension Mistakes (Part 1)

An extension can be a fantastic way to add room, boost property value, and create a space that better suits your family or lifestyle. However, getting it wrong can be expensive, stressful, and sometimes irreversible.

Obtaining advice from an architect is invaluable. With many an extension under our belt, we have solved some of the most complicated challenges, often where others have failed. In part 1 of a 2-part series, we let you in on the most common house extension mistakes – and give you advice on how to avoid them. 

Not Having a Clear Purpose

The Problem:

Perhaps your family has grown since you moved into your dream home, or you’ve purchased an inner-city property that needs some work - it’s tempting to throw yourself into a project with only a vague idea of ‘wanting more space.’  

Without a clear brief or a detailed plan, you risk facing delays, overspending, and design issues.

After such a significant investment of your time and money, the last thing you want is a space that doesn’t function in the way you want it to.

The Solution:

Define exactly what you want from your extension – is there a particular problem that you want the extension to solve? For example, do you need an extra bedroom, a bigger kitchen, or a home office? Perhaps you want to create a stronger connection to the outdoors or a space to entertain. Understanding how you want the space to function will enable you to clarify your brief.

Consulting with an architect will help you understand how your goals can be achieved in addition to identifying any issues you haven’t yet considered, such as how your proposed extension will impact the flow and function of your existing home or whether planning permission will be required.

It’s also important to think about how you want to feel in your extension. Do you want the space to feel cosy and intimate or spacious and open plan? A good architect or designer will help you to think through these decisions in the early stages, ensuring that the end result meets your needs and expectations.

At OVS we ensure your extension is seamlessly integrated into your existing home, maximising space and natural light while adhering to the highest standards of craftsmanship

Ignoring Planning Permission and Building Regulations

The Problem:

Planning permission involves obtaining official approval from your local authority for certain types of building work. It is tempting to assume that because similar extensions exist in your area, you won’t need planning permission. This assumption can backfire, resulting in enforcement action that halts construction, or worse, the demolition of unauthorised work. In some cases, extensions do fall under ‘Permitted Development Rights,’ meaning your project does not require planning permission - but not always.

The Solution:

Always check with your local planning authority. Even if permission isn’t required, your project must still comply with building regulations, such as covering structural integrity, fire safety, insulation, and more. Failing to get the necessary approvals can result in fines, orders to undo the work, or problems when you try to sell.

Consulting with an experienced architect is key to avoiding planning permission pitfalls. At OVS, this is one of our key services - we have a 97% success rate in securing planning permission. We work closely with you every step of the way to maximise your chances of success within a very complex system.

Take a look at our journal for recent posts on planning permission and permitted development guidelines.

Underestimating the Budget

The Problem:

Budgeting for a house extension can feel daunting. It can be easy to focus on the cost of construction and neglect the significance of other costs such as planning permission fees, structural engineering fees, party wall agreement costs, utility connection fees, VAT, materials, finishes, and contingency funds. Many homeowners also fail to account for unexpected issues like structural surprises or utility relocation.

The Solution:

We recommend obtaining a detailed quote and building in a contingency of at least 10-15% for unexpected costs. Factor in fees for architects, engineers, planning applications, inspections, and possibly temporary accommodation. It’s better to be pleasantly surprised than financially blindsided.

A key to unlocking value and minimising costs is hiring an experienced architect. OVS can help reduce the cost of your home extension by designing efficient spaces, selecting cost-effective materials, and navigating complex planning regulations. Sustainable, locally sourced materials go a long way to lowering energy costs and boosting long-term property value. Our team also identifies potential structural issues early and engages only trusted contractors, thereby avoiding costly surprises during construction.

Hiring the Wrong Builder

The Problem:

Choosing the wrong builder can be a costly mistake that results in badly completed work or even an abandoned project. Poor workmanship, communication issues, budget overruns, insurance issues, lack of accountability, or a contractor disappearing halfway through a job are, unfortunately, common issues. Don’t be tempted to rely solely on recommendations or word of mouth, and it goes without saying that cheaper does not equal better.

The Solution:

This is where research is key. Obtain at least three quotes, check references, and review portfolios. Ask about experience with similar projects. A reputable builder should be happy to provide credentials, testimonials, and put everything in writing.

A skilled and experienced architect will you help you find the perfect builder for your project. After working with an impressive roster of contractors over many years and across myriad projects, we understand firsthand the vital importance of a trusted tradesperson. This experience led us to write a handy guide, Top 7 Tips for Picking Your Builder. We work with only trusted and reliable contractors that ensure the construction process is seamless.

Here to help

A successful home extension enhances both the functionality and value of your property. But to get there, it’s crucial to avoid shortcuts, plan thoroughly, and surround yourself with the right professionals. It is never too early in the process to get professional advice. Contact OVS today to discuss how we can help you on your journey to designing your dream extension.