House Extensions 101: Designing Your Extension, Designing Your Lifestyle

A successful extension is all about starting with a goal and working backwards.


That’s why our clients usually come to us with a problem to solve. We want to spend more time as a family. We want a house that’s suitable for entertaining. We love cooking but our kitchen isn’t big enough. Our kids are getting older and want their own space. I need a quiet part of the house so I can work in peace!


Sound familiar? Before you make any moves on your house extension plans, read this guide by Heronlake. We’re covering everything from design inspiration to whether you need to hire an architect or can go DIY.

How do I find an architect to design an extension?

Without a referral to go off, your first stop to find an architect near you for a house extension is the ARB directory. Only ARB-registered professionals can legally use the title ‘architect’ and to be accepted, they must have completed 7 years of training, 5 years of study and 2 years of practical experience.

Bonus points if you find a house extension architect who is a chartered member of the Royal Institute of British Architects (RIBA). This qualification is proof of their commitment to high-quality design. Chartered architects have taken steps to progress their skills and knowledge, so you can be pretty confident your extension design is in good hands.  

But that doesn’t mean it’s not worth doing any due diligence. Before signing on any dotted lines:

  • Ask to see the architect’s portfolio of work
  • Request references from previous clients
  • Check online reviews
  • Make sure they have a positive and proactive attitude
  • Ask for evidence of their insurance status

Can I draw my own plans for an extension?

You’re not legally obliged to hire a fully qualified architect. So if you have a vision and can think both strategically and creatively, you can try your hand at designing an extension on your house.

However, a word of warning from Heronlake: designing a house extension is an awful lot of work for the uninitiated and those without the programmes or knowledge of the workings of local authorities. DIY design almost always takes up more time than people are prepared for, too.

Keep in mind that if you’re not a qualified architect, there are limits to what you can design. And, since the cost of extensions is at a high, getting the design right is crucial to the success of your renovated space.

There are some occasions when we’d strongly recommend working with an experienced house extension architect:

  • Your ideal home extension is complex
  • You live in a listed building, so need someone who understands the intricacies involved with making changes to it
  • You want to create an interesting contrast between the new extension and the original building. This can be hard to get right but looks amazing when you do
  • You also want to reconfigure your existing space to improve the flow
  • You have some awkward space to work with. For example, you’re limited by footage or neighbours
  • You feel that obtaining planning permission will be a difficult or daunting process (architects can simplify this for you!)

How can I design my house extension?

Ready to go full-steam ahead and feeling confident about DIY-ing your house extension plans? Let’s get you off on the right foot.

If you can, get some original plans of the property – they will give you an excellent starting point. Estate agent drawings can be a useful backup but they’re not to scale. Get your hands on several copies of the plan or drawing and experiment with layouts. It’s surprising what you don’t see at the outset and what develops when you play with configuration.

To work out what your vision involves, it’s usually best to start with what you don’t want and finish with what you do want. Get as clear as possible but – and we can’t stress this enough – get the attention of an experienced builder early on. It will pay off. 

Below, we’ve gathered some starting points to help you design a home extension. They might be kick-starters you hadn’t thought of, so it’s worth working through them all.

1.Consider imbalances

A successful renovation usually addresses an imbalance in the home. Is your living room too small? Do you need an extra bedroom? More office space?

2. Creating flow

Consider how people will move through the house. This isn’t just about incorporating more corridors, but about getting seamlessly from A to B (often through open-plan living). Think about the flow of movement from the kitchen to the dining area, and from bedrooms to bathrooms, for example.


Decide which furniture you want to keep or incorporate. This can be influential to the design of your extension.

4. Think: Simplicity, productivity, happiness

Think about how your home can make your life easier and more enjoyable. What day-to-day tasks are draining and more difficult than they need to be? Does anything feel cluttered or in-the-way right now? Examine things like how you wash and dry clothes, store shoes, and where your pets eat and sleep.

5. Light it up

Prioritise light to dramatically enhance your space. Natural light is best (think bigger windows, bi-fold doors and skylights) but where sunlight isn’t possible, consider bringing more feature lighting to the home.

How can my home suit my hobbies, business or lifestyle?

It’s tough to answer that without visiting your home and getting to know you some more. With that in mind, you can book a free home visit to chat about your house extension plans.


Until then, why not take some inspiration from our previous clients? We work with homeowners and local house extension architects to design an extension that perfectly fits our clients’ lifestyle goals.


1. Zone out


A unique, effective way to achieve a multi-functional home is through a “zoning” technique. This involves partitioning sections for whatever matters to you – whether that’s studying, relaxing, or having a dedicated utility room. Maintain the open-plan feel by creating zones through banquette seating, half-height walls or even just sofas. Our client in Busbridge perfected the partition.


For homeowners that need more privacy than open-plan living can offer, consider a garage or loft conversion. Specified space for a home office, studio or workshop can be a game-changer for productivity. 


2. Functional features


Think about what matters most to you and make it a part of your everyday. If that’s working out, create space for a home gym. If you love cooking for friends and family, connect the kitchen with the dining room for a social-centered home. If you’re a big reader, in-built bookshelves make a beautiful feature.


A client of ours opted to glaze the corner of her home so she could watch her children playing in the garden. Out-of-the-box features go a long way to make your home a truly purpose-built building.


3. Bring the outdoors in


Outdoor living is a huge home design trend at the moment. Glazing and greenery keep us connected to nature, which can have positive effects on our mood and well-being. Take a leaf out of this client’s book: They incorporated an eye-catching nature wall that flowed from the inside out.

Bring in the experts to maximise your space

An extension is one of the most exciting upgrades you can make on your home, so it’s natural to want to go full steam ahead. Especially if you’re buzzing with ideas.


We recommend bringing in a house extension architect near you at some point during the design process, even if you want to have lots of input on the final result. A qualified architect can help you manage your budget in a better way, and guide you through the complexities of planning permission, building regulations and party wall issues. On top of that, a professional eye is invaluable to ensure you’re maximising your space and creating a liveable “flow”.


Wherever you’re at in your home extension plans, bring Heronlake into the equation. We can help solidify your vision and explore ways to make your goals achievable.

Contact Heronlake