How to keep your extension costs down

Johannes van Graan Johannes van Graan
Zinc Extension, Urban Creatures : Architects Urban Creatures : Architects Modern houses
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In need of some extra space? In these cramped times, who isn’t? Fortunately help is possible in the form of an extension like a conservatory or possibly even a greenhouse. Not only are these wonderful additions to homes that extend one’s living spaces, but can also make a positive impact on a house’s design and resale value.

But what can you do to keep the costs down? Let’s find out…  

1. Match the architecture to your current house

Private House - Holland Park , New Images Architects New Images Architects Modern balcony, veranda & terrace
New Images Architects

Private House—Holland Park

New Images Architects

By that we don’t mean that your add-on needs to match your existing house’s design, material and colour 100%. For instance, a wooden extension can still match a traditional-style home, even if the colours and materials don’t link up visually.

However, when viewing the finished result from afar, the one structure has to complement the other in terms of design. This will definitely impact your home’s resale value down the road. 

We recommend speaking to a professional, like an architect, who has a clearer eye for this type of detail. 

2. Know what you can do… and what you can’t

We understand that a lot of DIYers relish the chance of carrying out projects themselves to keep the costs down, but bear in mind that adding an extension is one major task! 

The facts are these: if you’re not experienced enough to handle this type of project, you’re going to be wasting materials, time, and money. And it won’t take long before you (or others) realise that what you’re trying to accomplish isn’t viable – or safe!

Thus, to help keep costs down, get an experienced professional in right from the very start. You can always cut expenses at the end stages of the project, like taking care of the painting and décor yourself. 

3. Go for glass

Project: No.10, IQ Glass UK IQ Glass UK Modern windows & doors Sliding Glass Doors,Glass Extension,Structural Glass
IQ Glass UK

Project: No.10

IQ Glass UK

In terms of low-cost extensions, conservatories with glazing can come in much cheaper than opaque walls made of concrete, wood, etc. This, obviously, depends on various factors like size, your contractors, location, etc.

However, glazing also presents a heap of other benefits like more natural lighting, better views (if your garden is up to scratch), and a roomier feeling for your interiors. 

4. Keep space in mind

Single Storey Extension, Roxborough Rd II, London Building Renovation London Building Renovation Modern houses
London Building Renovation

Single Storey Extension, Roxborough Rd II

London Building Renovation

If you’re going to be spending money on an extension, you may as well ensure that you get what you need.

Ask yourself which scenario will work out the most expensive:

A) Spending money on a tiny extension now and then spending more costs a few years later to make said extension bigger;


B) Spending a bit more now for a bigger add-on that has all the space you require.

5. Be careful with your materials

Single Storey Extension Reginald Road - Northwood, London Building Renovation London Building Renovation Modern windows & doors Aluminium/Zinc Grey bi-folding
London Building Renovation

Single Storey Extension Reginald Road—Northwood

London Building Renovation

Obviously your choice of materials will also influence your expenses. Wood, for example, is available in numerous styles, colours and textures, and can greatly differ in pricing depending on which type of timber you opt for – again, here is another discussion to be had with your architect or designer.

Other factors that can also help keep costs down is the style / shape of your extension – straight walls and flat ceilings don’t require special constructions, for instance. 

6. What about permits?

It’s your property, of course, but that doesn’t mean you can make and break as you like. Things like permits, building rights and Planning Permission all come into play, which is why it’s crucial to speak to your local council to find out what’s allowed.

Your architect can also help you with these rules.

Keep in mind that continuing with a build that hasn’t been approved will result in a tear-down and, you guessed it, extra costs on your part!

7. Opting for a wooden structure

As already said, wood is one of the cheapest alternatives in terms of building materials (depending on the type, of course). But as wood is also very versatile (it can be painted and styled however you want), it’s definitely recommended to keep it as an option if you’re looking to keep costs down. 

8. Inspiring designs to look at

Rear Extension Phi Architects
Phi  Architects

Rear Extension

Phi Architects

To further inspire you for your extension, have a look at these top-class designs that differ in size, style, colour, layout, etc. But do you want to know what they all have in common? They all came in for much cheaper thanks to creative tweaking and out-of-the-box thinking!

Dukes Avenue Coupdeville

Dukes Avenue


Extension to a Grade II Listed Building WHITTAKER DESIGN

Extension to a Grade II Listed Building


In terms of abiding by the law with your extension, best have a look at Planning permission: Do you need it? 

What other tips and tricks do you know to help keep costs down when building an extension?

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