Costs to build extension.jpg

Investing in a home extension is one of the best ways to give yourself more valuable living space without having to move. Eventually, every homeowner needs to think about whether or not they need more space; it could be that they need to make room for a new family member, or it could simply be that they are ready to move up the property ladder. However, the current property market can make simply moving to a larger home an impossibility, especially in areas like London. 

Depending on the costs involved, building a home extension could make more financial sense than moving. It is relatively simple to collect quotes to compare to the cost of an entirely new property. Plus, if you love your home and the area you live in, you may prefer to stick around!

If you are interested in building a house or flat extension, your first step should be to speak to a local builder or structural engineer about your plans. Hiring an architectural designer to create accurate plans will be a big help, especially when it comes to making applications for planning permission, building regulations approval and so on. 

Need a Structural Engineer?
Fill in a quick form to post your job
Group 4

The key at this point will be to collect as many quotes as possible in order to give you a clear idea of the costs involved in building an extension. While there are several cost calculators online, these rarely produce accurate figures; quotes can vary significantly depending on the size of your extension, your location the UK, the materials used, local utilities and so on.

Once you have a good idea of the costs it will be a good idea to speak to a local estate agent. Ideally, the investment in your extension will be reflected in the value of your home; however, if your property is already highly valued for the area, this may not be the case, meaning that it could make more sense for you to move after all.

It should go without saying when embarking on a larger home improvement job that you should establish a paper trail and collect invoices for every service provided by your Pros. This will give you a record of what you paid for and when, allowing you to hold Pros accountable for sub-par work if necessary. 

When you book a job via, the website keeps all messages and transactions on file, allowing customers to access them quickly. The Plentific support team is also equipped to diffuse any negativity between Pros and customers, ensuring that jobs are completed to a high standard. Finally, by booking your Pro via the Plentific platform, you will also have your investment protected by the Plentific Guarantee.

Costs of building extension.jpg

Before contacting any Pros about your home extension, ask yourself what kind of extension you actually want. How much space do you want to add to your home? Are you happy to add plain rooms, or will you need a new bathroom or kitchen? What kind of decor will you want to add? The more that you can decide on at this early stage, the easier it will be for you to collect accurate quotes.

Keep in mind when budgeting for your project that you will also need to add professional fees. Hiring a structural engineer, architectural designer and so on will usually add around 10-15% to your costs. Depending on the size of the firms that you hire for the work, you may also need to factor in VAT.

Extension Costs.jpg
Need a Builder?
Fill in a quick form to post your job
Group 4

One of the most important parts of planning your project will be deciding whether you want a single or double storey extension. You will usually be told that a single storey extension costs between £1,000 and £1,500 per square meter, but the actual costs can be much more in areas like London. The cost of a two storey extension will usually be around 50% higher than a single.

Unfortunately, these ‘averages’ usually only apply to the most basic extensions. For example, adding a new bathroom can cost at least £5,000, while a new kitchen can easily cost over £10,000. There will also be additional costs for higher-tier decor and home features, such as floating staircases. Utilities can also raise your quote: how many plug sockets will you want to include in your extension? What about radiators? What about lighting? 

You could also see your quote increase as a result of the circumstances of your property. For example, if there is limited access to the prospective work area, your Pros may find it difficult to get the appropriate equipment through, causing the project to drag on. Similarly, if there are any utilities that need to be relocated, such as drains, sewers or buried pipes, you will need to factor in these costs as well. The structure of your home can also be a factor: will you need to take down or replace any internal walls? Finally, does your property share a wall with a neighbour? If so, a party wall survey may be required.

Building Extension Costs.jpg

To put it simply, building an extension will force you to consider a huge number of variables, so it will be crucial to invest the appropriate amount of time in your planning stage. An architectural designer can be a big help here; based on your budget, they can make sure that your plans stay realistic by identifying potential cost-cutting methods, emphasising simple designs and helping you to source materials.

While it may seem to cheaper to act as your own project manager, this is a bit of a false economy. You will need to hire Pros, work with your local planning authority, liaise with everyone and buy your own materials, all of which can take up more time and money for someone who does not have any experience. Having an experienced builder or architectural designer act as your project manager may seem like just another added expense, but it can actually end up saving you money in the end.

An important thing to keep in mind before hiring your Pros is that extensions can often take several weeks. For a smaller job, you would be required to make a deposit and then pay the outstanding balance once everything is finished, but for a project like this you may be required to make interim payments. What you will not be required to do is pay all of your costs up front. If a Pro asks this of you, it may be best for you to hire someone else.

Finally, once you have a solid plan in place, try to stick to it as much as possible. Trying to make last minute changes can cause your costs to shoot up. Instead, invest as much time as possible in your planning phase and only move forward once you are completely happy.