Double-Storey Extension: The Essential Home Extension Guide

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Double-storey extensions are considered one of the best ways a person can improve their home, making it larger and creating a home layout that works for them. Bespoke Construction Group are double-storey house extension experts and we’ve seen first-hand the difference this home improvement method can make to a property. 

It’s true that there are multiple ways homeowners can make their homes larger. However, for this blog, we will be focusing specifically on the double-storey extension. Join us as we highlight some important factors to consider if you’re thinking of taking on an extension project such as this. 

What is a Double-Storey Extension?

A double-storey (or two-storey) extension is a structure that consists of two floors and is built onto the side, front or rear of an existing property. The purpose of this is to make the original home larger. 

As an alternative to a single-storey extension, a double-storey extension can provide a lot more extra space for a home, often allowing the homeowner to create additional living spaces as well as enlarge original rooms in the household. 

Interior of a double-storey extension by construction company Norfolk.

The difference in added space achieved is just one varying factor between a single- and double-storey extension. If you want to enlarge your home with an extension but aren’t sure how many floors you need, read our previous article: Should I Build a Single or Double Storey Extension?

Home Extension Project: Double-Storey Extension Before and After

At this property in Dereham, our construction company aided our clients by building a two-storey extension onto their cottage property. 

Exterior of double-storey extension from Bespoke Norfolk Group.

To stay in the home they love, our clients knew they needed to create more space for their home and after meeting with our management team, it was decided that the best way to achieve this was with a double-storey extension. 

As a result of this home extension, this property has been able to:

  • Create extra room for a new dining space on the ground floor 
  • Add an extra bathroom on the first floor 
  • And finally, enlarge the size of their child’s bedroom 

To complete this extension project, we added modern exterior cladding which created a lovely twist to this older property. To create your dream home with a new house extension, speak to our team of local construction experts today. Get in touch now!

The Cost of a Double-Storey Extension UK

The price of a double-storey extension can range from £65,000 to £100,000 in the UK, and in some cases can fetch a price tag of £150,000 or more.

Coastal home's balcony area that over looks the Norfolk coastline.

Keep in mind that the cost of a double-storey extension varies depending on several factors including:

  • The size of the extension – the larger the extension, the more money 
  • The quality of the build
  • Architectural services and fees 
  • The level of foundations and groundworks needed 
  • The location
  • Purpose of rooms being created – rooms like kitchens and bathrooms require more work and money to install 
Hallway of home that leads to a bright and light living space with seating areas.

There are even more factors to consider that aren’t listed above. This is one of the reasons it may be a good idea to work with a design and build construction company when working on a two-storey extension. This means you can work with one contractor to take your project from start to finish. 

Two-Storey Extension Planning Permission 

You may be wondering if you need planning permission for a double-storey house extension (which can add to the cost). Through permitted development rights, it is possible to build an extension with two floors without planning permission.

Bespoke Norfolk Group builder working on a construction site.

However, this is not as common as single-storey extensions as many view the guidelines/restrictions as too limiting to build a double-storey extension under permitted development rights. Such restrictions include:

  • You use similar materials to the existing dwelling 
  • Your extension takes up less than 50% of the land around the existing dwelling 
  • Your extension must take up less than 50% of the width of the existing dwelling 
  • Its eaves and ridges are not taller than the existing dwelling
  • The existing dwelling is not a single-storey home 
  • Terraces must be no more than 3.5m higher than the next tallest terrace

While planning permission can be a challenge for some, Bespoke Construction Group have a 100% success rate in getting home extension projects through planning permission. Speak to us about planning permission

*Keep in mind that some properties cannot access PDR, such as homes situated on the Norfolk and Suffolk Broads.

How Long Does a Double-Storey Extension Take to Build? 

A double-storey extension will take, on average, around 9-11 months to complete. Like the pricing of an extension, the timeframe for a project like this is variable and depends massively on different factors, such as size, materials, location, etc. No two home extension projects are ever the same. 

Clean and tidy kitchen and dining area with wooden table, countertop and floors.

While this can be a huge commitment for a household to undertake, you must weigh the pros and cons. Indeed your home may resemble more of a construction site for just under a year, but that could result in your home being transformed into something incredible. If a smaller build time is what you’re after, then you may be better off building a single-storey extension. These take around 2-4 months.

Will This Type of Home Extension Add Value?

When someone decides to renovate or extend their home, there is always the very real possibility of adding value to that property. What do we mean by adding value? Through home improvements, a homeowner can increase the monetary value of their property, potentially allowing them to sell the house for a higher price than what it was bought for.  

A double-storey extension can add value to a home, and oftentimes this is around 10-20% of the cost of the home’s original price. 

Double-storey extensions that add an extra bedroom and bathroom to a property will normally lead to the higher end of added value, as the home is being made much more desirable with added rooms. 

It’s important to remember that only high-quality extensions have the ability to add value to a property. Poorly built extensions can have the opposite effect and bring down the price of a home. 

Double-Storey Extension Ideas

Two-storey extensions can be used in many different ways to improve the size and practicality of a home. From creating an open-plan home layout to changing up the exterior of your home, there is a whole host of double-storey extension ideas to inspire you. 

Here’s a look at some of our favourite double-storey extension ideas. 

Double-Storey Front Extension

Norfolk home that has been extended at the front with a double-storey extension.

While most home extensions are placed at the side or rear of a property, it is possible to add an extension to the front of a home. By extending at the front, a home can look almost unrecognisable from how it looked before. This is a particularly good idea if there is plenty of room in front of a property but not so much at the back or sides.  

Two-Storey Extension on Bungalow

Bungalows have the common problem of being too small. When a normal home is too small, the general answer is to extend, and this is also possible for bungalow properties. Suddenly, a bungalow that was once too small with just one floor benefits from added space and an extra floor. 

Contrasting Exterior to the Original House 

Double storey house extension with a mixture of external cladding and brickwork.

Sometimes, a clash of styles is welcomed and can be a great way of adding some character to a home and helping it to stand out from its neighbouring properties. With the construction of your new extension, try adding cladding or building with timber to counter the exterior of the original home.

Glazed Double-Storey House Extension 

Home extensions aren’t just for making a home larger. Some have been known to use an extension as a means of creating more light for a home as a way of improving home life. There are so many benefits to living in a home that is flooded with natural light and adding a fully or partly glazed extension could be just the solution. 

Other Types of Home Extensions

The focus of this blog has been double-storey extensions, but before finishing, we wanted to highlight two other forms of home extensions that do just as good a job of enlarging homes and providing homeowners with the option of staying in a home they love. 

Timber Frame Extension

Timber frame extension built onto cottage property by construction company Norfolk.

Timber frame extensions can come as both single- or double-storey. Built using timber as opposed to brick and mortar, these extensions are sustainable, usually faster to build, and can also retain heat better than brick. Read: A Beginner’s Guide to Timber Frame Extensions and Construction.

Single-Storey Extension

Home extension with one storey built onto existing property.

We’ve mentioned this type of home extension throughout this blog. This is an ideal extension method for smaller home construction projects. As opposed to building two stories, this extension includes only one storey/floor. Read: Single-Storey Extension: The Complete Home Extension Guide. 

Final Thoughts on Two-Storey Extensions 

Bespoke Construction Group are experienced home extension professionals and we serve our local communities by providing high-quality home construction services. 

If you want to reimagine your home with a double-storey house extension, we can help. Comprised of the best construction, architectural and design experts around, we create living spaces that blow our clients away. Perhaps we can do the same for you. Find out by getting in contact with our team

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If you’re interested in any of our wide range of services, you can easily schedule a free consultation with us for no-obligation advice