One of the most remarkable and effective ways to transform your house into your dream home is to extend upwards and outwards at the same time. Double storey extensions are expensive but compared to the cost of buying a sizeable property in the area you’re settled in, they’re a cost-effective choice. And that’s not to mention the benefits of being able to maximise the value of your investment and design your home to your unique specs. If you have the space for this type of extension, we’d highly recommend that you get a quote on your favourite double storey extension ideas from a bespoke construction company before you consider a costly move.

How Much Does a Double Storey Extension Cost?

As with all building projects, the cost of a two-storey extension depends on several factors, including:

  • The location of your home and accessibility of the site – How far suppliers and teams need to travel, how easy it is to get materials onto the site, if you need a crane, etc.
  • Composition of the soil – This impacts foundation and structural requirements.
  • The size of the project – The larger the project the more labour and materials are needed.
  • The type and shape of the roof – Flat roofs tend to be more affordable than pitched, gabled, or crown roofs.
  • Your selected finishes – The cost and availability of your selected windows, doors, heating, flooring, and cabinetry, etc.

What Additional Costs Should I Expect?

These are complex and time-consuming projects, so it’s essential to include additional fees in your budget. Depending on the project, this can include:

  • Architects’ fees
  • Project Management fees
  • Survey costs
  • Structural engineer fees
  • Planning application fees
  • Building control charges
  • Party Wall Agreements
  • Interior fit out costs

All these costs depend on the specialists your project requires, negotiations for providing these services, and the organisations you partner with. Often, it’s a good idea to keep as many of these services with one party as possible, which streamlines the process and helps to keep costs down. This is where using a construction company that handles the project from start to finish (from design through to completion) can be exceptionally cost effective and hassle-free.

Planning Permission for a Double Storey Extension

These extensions do require planning permission, so it’s important to take this into consideration when looking for double storey extension ideas. Again, a bespoke construction firm will be able to guide you through this process and ensure that your plans are within all requirements.

Generally, the main contended aspect of a double storey extension is its height. The height of the extension’s ridge and eaves should not be higher than the existing roof and eaves. If your current property has low ceilings, these ceilings may be raised to accommodate a taller extension, or the extension can be set a little lower on the ground.

In a conservation area or if you have a period home, you might not be allowed to have a flat roof extension, but your design team can give you guidance here. Again, this can be incorporated into your design ideas in different ways, for example, by having multiple traditional pitched roofs or a crown roof design that gives the impression of a pitch with a flat roof hidden behind it.

Another consideration is the footprint of the extension, or how large it can be. Planning permission limits a double storey extension, saying it must project no further back than a line set at 45 degrees horizontally from the centre of neighbouring windows (sightlines), with a width less than 50% of the width of the existing house and a maximum length of 3m for terraced or semi-detached houses and 4m for detached houses.

Will a Double Storey Extension Add Value to My Home?

The answer to this question is almost always a resounding yes. Living space is the single-most in-demand factor for buyers, and people are willing to pay a premium, especially in high demand areas. How much value this will add is a different question.

We recommend getting quotes on a double storey extension for your home to get a clear idea of the costs. Then, you can measure the short-term costs against the cost of moving to a similar home in your area, remembering to factor in stamp duty, removal costs, and other expenses relating to a new home.

To get an idea of the value of your current property, you should get a valuation from 1-3 estate agents. Then, using your extension quote, measure these costs against similar homes for sale and recent homes purchased in your area. Remember to compare these based on price per meter, but also consider factors like the quality of the home’s design, desirable features you will have in your extension, and other aspects that add to buyer appeal.

This will also help prevent you from overspending on your double-storey extension or overinvesting in your property. Be Inspired By This Double Delight in Elmbridge

Double storey extension in Kings Mead Park, London

Planning permissions and fees aside, building a double storey extension is a creative and inspiring project. This Kings Mead Park home experienced a new, modern lease on life through a project that extended the ground floor out into the garden for a large kitchen and living space, created a new hallway WC, expanded the main bedroom into a king-sized suite, added a new 3rd bedroom, and flooded the space with natural light. Modern, chic, and with an eye on indoor-outdoor living, the design is enriched with sleek lines, quality finishes, and bold colours, creating a family home that’s the envy of the neighbourhood.

See more house extension ideas here.

For more double storey extension ideas or to get a quote on double storey extension plans, call the team at Plus Rooms today. We are an experienced, full-service design and construction business, handling every aspect of your construction projects and with an exceptional track record of completing over 1,400 projects in homes throughout London to world-class standards.