House Extension

The cost of a house extension depends on the scale of the project, including your preferred finishes and the level of structural work required.

In the North West, most extensions range from £1,500–£2,500 per m². Costs will likely rise if you decide on bespoke design, high-end materials, or complex construction. You should also factor in planning applications, professional fees, and VAT.  

The best way to get a clear indication of costs is with tailored house extension plans, which PDK provide at the start of every project. 

There’s no standard approach to extending a home. Popular house extension options include: 

Single-storey extension: for open-plan kitchens, family rooms, or orangeries. 

Double-storey extension: for extra bedrooms, bathrooms, or home offices while maximising ground-floor space. 

Rear extension: for extending into your garden for a larger living or dining area. 

Side extension: for expanding narrow kitchens in terraced or semi-detached properties. 

Wrap-around extension: for transforming the flow of your home with a combined side and rear extension.  

Each type of extension has its own benefits and planning considerations. PDK’s architectural design team will help you decide which option works best for your lifestyle and property. 

Double-storey extensions typically cost between £1,200 and £2,200 per m². Although the upfront spend is higher than a single storey, the cost per square metre is lower, making it a cost-effective way to gain significant space. Factors such as the number of rooms, structural complexity, and finish quality will impact the final figure. 

Single-storey extensions usually range from £1,500 to £2,500 per m². A straightforward rear extension with standard finishes may sit at the lower end, while projects involving large glass openings, bifold doors, or high-spec kitchen design will be higher.  

We’ll work with you to balance your vision with budget to ensure your investment delivers the space you need. 

If you want to keep your project on track, yes. Home extension plans provide accurate dimensions for pricing, ensure compliance with building regulations, and act as a clear guide for contractors. Without detailed drawings, extensions can run into delays and unforeseen costs.  

PDK create comprehensive house extension plans, giving you confidence that your design is practical, safe, and ready for approval. 

Not all extensions require planning permission, as many fall under permitted development. However, you may need formal approval if your home is in a conservation area, is listed, or the extension exceeds specific limits.  

PDK will ensure your project has the correct permissions in place. 

A well-designed extension can increase your property’s market value, as  additional living space, modern layouts, and extra bedrooms or bathrooms are all desirable to buyers.  

Timelines vary depending on the project’s size and scope. A small single-storey extension might take 8–12 weeks once construction starts. In contrast, a larger or double-storey project can take several months.  

PDK will provide a clear schedule as part of your house extension plans, so you know what timelines to expect.