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House Extension Cost – How To Determine Your Budget

house with scaffolding around it indicating the construction of a home extension

House Extension Cost – How To Determine Your Budget

Things to Consider
While Budgeting For Your
Home Extension Cost

In this post, we’re going to discuss the key factors that determine your house extension cost.

Undeniably, when it comes to increasing a home’s existing space, a house extension is the most popular and effective option. It not only makes a home more spacious but more functional as well.

For any homeowner who is thinking of extending their home, the first thing to do is set the right budget for your house extension.

Of course, you’ll need to hire a cost consultant or contact a reputable builder for a free home feasibility study to get accurate cost estimates but understanding the following factors beforehand would help you set the right expectations right from the start as house extension costs can vary.

Factors That Contribute To Your House Extension Cost

Specifications

In any house extension project, specification is one of the biggest factors that can dramatically impact the total cost. The quality of products, materials and the kind of finishes you want to have are probably the first thing you’d want to consider while making these calculations.

If you list top-quality fittings and finishes in your specifications, the cost is likely to be a lot more than what standard-quality materials will cost you. It pays to be realistic.

Type of Extension

You probably know already that there are many different types of home extension projects that can be executed. From basement and rear extensions to side extensions and loft conversions, with kitchen and bathroom layouts to consider – a lot can be achieved if you’ve got the area and the money.

It is always a good idea to research what type of house extension will work best with the existing layout of your house because this will have a direct impact on the cost. For example, a garage extension or a simple loft conversion will cost significantly less than the addition of an annex or a glass extension. A basement extension would probably cost much more.

Number of storeys

It’s important to note that larger extensions would help you get the maximum out of your investment, thanks to economies of scale.

Assuming you’ll be keeping the same specifications, a two-storey extension would not cost more (per metre square) compared to a single-storey extension. This is because you will still need to add floor joists and walls in both cases to build the foundations and the roof.

Some homeowners opt to have a two-storey extension instead of a single-storey because it is better value when it is possible. What you need to remember is in the case of a two-storey extension, the overall cost will be higher, but your cost per metre square will be lower, comparatively.

Location

If your house is in an upscale neighbourhood, you are likely to spend more on extension costs because you may want your house to blend in with other pricey houses in your estate.

On the other hand, if the house is situated in a gated community, there might be restrictions on modifying the facades of the homes. For example, you might be limited to executing only rear house extension projects or make use of the backyard space, so it doesn’t tower over other people’s backyards.


The above factors will consume most of your house extension budget, there are several other factors to consider as well. These may include architectural consultant fees, structural engineering costs, and planning application fees, to name a few.

Additionally, you will pay VAT on materials and labour at a standard rate as part of your house extension cost.

If you’re up for it, you may want to manage your house extension project yourself. Taking such a route will definitely help you lower your house extension cost dramatically, but you should expect to invest a considerable amount of time and effort to ensure everything goes smoothly.

On the other hand, hiring a chartered building company and consultancy means the team you hire will be responsible for the entire project – from contacting individual trades to get the best deals to monitoring the work and ensuring timely completion, minimising the disruption to your home life.

Remember, it is wise to obtain 3-4 quotes from reputable local builders before selecting the one you think will deliver on your vision. If we are local to you, that may be us!

If you need a pricing guide and are based in or near Sidcup/Bexley/Kent, give us a call or drop us a line.

Craymanor offers the highest level of commitment & experience a Kent builder can offer