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Five Things You Need to Know Before Building a House Extension

For many people, their houses are their most significant financial assets, but for them, the value of their homes is not just limited to financials. When it comes to the walls, the roof, the brick, and mortar, it is just a house. But when people make their houses their homes, an attachment develops. 

A home is a place where you spend the best days of your life with your loved ones, and make the most precious memories of your life. But if there comes a time when you grow out of your homes, you are presented with two choices – move out to a new one or make renovations to the existing one. There are external as well as internal factors that affect this decision. 

According to research, an increasing number of people are preferring to improve their homes instead of moving due to external factors such as the rising property costs and the prevailing economic conditions.

However, internal factors such as attachment to the place can also play a significant part in influencing decision making. Therefore if you want to make improvements to your house, a house extension is an excellent place to start from, as it will add space, value, and utility to the site you hold so dear to your heart. 

A house extension is a project that you will invest in financially as well as emotionally, thus it is only right that you go about it carefully and with proper planning.

And sometimes if you’re in an eco-sensitive area, you may have to get an ecology survey done before you get approval to build the extension. So it pays to research your options and requirements before breaking ground.

In this article, we have compiled a list of things that you should know before building the perfect house extension that is best suited for your requirements. 

Double-story extensions

Adding a second story (or storey as it’s spelled in the UK) to your expansion is an excellent tool to utilize space optimally.

A double storey extension cost is affected by factors, such as finish and location, which can potentially be much lower when compared to that of a single-story because the roof replacement cost and the excavation costs stay the same.

So this means that the space you will be getting with a double-story extension is double that of a single-story extension, but the cost per square meter will be less. 

One consideration to make here is whether the existing structure can hold the weight of a second story. If the building was built less than 25 years ago, then the foundations of that building might be deep enough to support the weight of the extension above. But if the building is older, you might have to strengthen the existing structure with a steel frame that is concrete embedded. The existing foundations can also be underpinned.

Planning permissions

The first thing you need to do before you get serious about planning the perfect house extension is to make sure you have the appropriate planning permissions from the concerned authorities. In most cases, you can proceed with building the house extension without any individual permits, but in the case of height restrictions or listed buildings, there can come halts in plans. 

Therefore it’s always better to be sure. You can get clarity by logging on to the website of your local council for relevant information. Alternatively, you can visit the concerned office or talk to them over the phone. If you do need permission from the planning department, hiring a qualified architect can ease the process as they draw up the building plans and submit them to the authorities for approval. 

Go over the practicalities 

In order for the business to proceed feasibly, you need to make sure the basics are covered, such as easy access for builders to the property. Once we have done all that, the next stage is the contractors, from those who will work on the construction to those who will deal with the installation of the roof like Golden Heights Roofing Company, electricians and so on.

Thus you will have to think carefully about the practicality of the project and determine if it will actually be possible, and then make arrangements accordingly. You might have to change the plans of the extension.

Similarly, if your property does not have a proper driveway, you need to determine whether the parking space will be sufficient for the builders and yourself. If there is not enough parking space, you might have to make arrangements for an alternative route from where the building materials can pass through. 

Consider the property value

Adding an extension to your house can potentially increase your property’s value and to find out whether that’s the case, you should use a calculator to give yourself a better idea before you start. You may be surprised to find that increasing the square footing of your home may only give you a small boost.

There is only so much value you can add to your house by building a house extension.

This is because the ceiling price for the houses in a neighborhood is typically the same and it is a common misconception that by adding a significant house extension, you will be able to increase the value beyond the ceiling price. Thus if the ceiling price of your house is too low and the costs relating to the house extension too high, you might want to consider moving instead of improving or adjusting your plans.   


When building a house extension, privacy is not something that crosses a lot of people’s minds. House extensions usually have windows and roofs that allow the natural light to come in, but the downside of that is that the same windows can expose your interior to the passerby’s on the street or your neighbors. 

One way to protect your privacy without compromising on your design is to add one-way window screens, and these screens will let the natural light in without exposing your interiors or obstructing your views. Alternatively, you can add blinds to your windows. 


House extensions are a great way to add space and value to your house and provide an alternative to moving. The things discussed in the article are essential to know before you build a house extension, as they will save your time and effort, and direct them to be used in the right places. 

What else do you need to know before building a house extension? Let us know in the comments below.

Jeff Campbell